Askar Ali Khan Blog

ERROR: This RRD was created on another architecture

2011-08-20T03:36:00.000-07:00

Recently I have to migrate our cacti installation to new machine during which i encounter few issues.

After copying the RRD files to new machines and accessing cacti web http://myserver/cacti gives empty graphs. (wired)

After digging the logs (in apache error log) found out that RRD files is not portable between different architechture.

ERROR: This RRD was created on another architecture

In my case the old machine was 32bit arch with 32bit OS, and the new machine is 64bit with 64bit OS.

Quick googling tells that using rrddump and rrdrestore one can transfer RRD between architectures with ease.

EXAMPLES

To transfer an RRD between architectures, follow these steps:

1. On the same system where the RRD was created, use rrdtool dump to export the data to XML format.

# for i in ./*.rrd;do rrdtool dump $i ../rrd/$i.xml;done
(to converted all the files in rrd directory to XML format)

2. Transfer the XML dump to the target system.

3. Run rrdtool restore to create a new RRD from the XML dump.

# for i in ./*.xml; do rrdtool restore "$i" "../rrd/${i%.xml}"; done

After this cacti was up and running with all the old graphs migrated successfully.

Installing Nagios-plugins and NRPE on Centos 6

2011-08-13T00:50:00.000-07:00

To monitor remote hosts CPU load, disk partitions, processes etc with Nagios, requires to install NRPE and nagios-plugins on the remote host.

Nagios-plugins and NRPE is not available from Centos official repositories, so first of all we need to configure RPMforge> repo from where to install the required packages.

Read my previous article before configuring and installing anything from third party repo.

Installing RPMforge on Centos 6

Download and install the rpmforge-release package. Choose one of the two links below, selecting to match your host's architecture. If you are unsure of which one to use you can check your architecture with the command uname -i

x386
# rpm -Uvh http://pkgs.repoforge.org/rpmforge-release/rpmforge-release-0.5.2-1.el6.rf.i686.rpm

x86_64
# rpm -Uvh http://pkgs.repoforge.org/rpmforge-release/rpmforge-release-0.5.2-1.el6.rf.x86_64.rpm

Do not forget to set the priority,

vi /etc/yum.repos.d/rpmforge.repo

[rpmforge]
name = RHEL $releasever - RPMforge.net - dag
baseurl = http://apt.sw.be/redhat/el6/en/$basearch/rpmforge
mirrorlist = http://apt.sw.be/redhat/el6/en/mirrors-rpmforge
#mirrorlist = file:///etc/yum.repos.d/mirrors-rpmforge
enabled = 1
protect = 0
gpgkey = file:///etc/pki/rpm-gpg/RPM-GPG-KEY-rpmforge-dag
gpgcheck = 1
priority=10

Now everything is setup now you can install nagios-plugins and nrpe packages from RPMforge repo

# yum install nagios-plugins nagios-nrpe

Running NRPE under xinetd

Edit /etc/xinetd.d/nrpe for

disable = no
only_from = 127.0.0.1 Nagios ServerIP

Restart xinetd service
# /etc/init.d/xinetd restart

My KVM howto

2011-08-03T00:08:00.000-07:00

Enabling KVM support on your hardware

The host machines need to be running either Intel VT or AMD-V chipsets that support hardware-assisted
virtualization.

# grep -E 'vmx|svm' /proc/cpuinfo

If this command returns output, then your system supports KVM. The vmx CPU feature flag represents
Intel VT chipset while the svm flag represents AMD-V. Note which KVM flag was returned as it will be
useful for loading the right module later.

Next you need to ensure the KVM-related feature is enabled in the BIOS

1. In the BIOS menu, select Advanced Step → CPU Options.
2. Make sure the Intel Virtualization Technology option is Enabled.

Installing and configuring KVM-related package

Install the KVM software using yum:
# yum install kvm

Install additional virtualization management packages:

# yum install libvirt python-virtinst libvirt-python libvirt-client bridge-utils

Configuring KVM after installing the packages

After you have installed the KVM-related packages, load the right KVM modules by following these
steps:

Procedure
1. Insert KVM module by running the following command:
# modprobe kvm

2. Insert the chip-specific KVM module by running one of these commands:
For the AMD chip (svm flag)
# modprobe kvm-amd

For Intel chip (vmx flag)
# modprobe kvm-intel

You can verify that the modules are inserted and running.
# lsmod|grep kvm
kvm-intel    86248 3
kvm     223264 1 kvm_intel

3. Start the libvirtd daemon service:
# /etc/init.d/libvirtd start

Starting libvirtd daemon:
# /etc/init.d/libvirtd status
libvirtd (pid 6584) is running.

4. Set up libvirtd to start on every reboot:
# chkconfig libvirtd on

5. Better to reboot the host machine.

Creating LVM for Guest OS (Run lvdisplay before creating new LVM)

# lvcreate -L 4G -n kvm5 vg_kvm

-L 10G = replace with filesystem size
-n kvm1 = replace with kvm#

Creating KVM guest using virt-install

virt-install --name kvm1 \
--ram 512 \
--os-type='linux' \
--disk path=/dev/mapper/vg_kvm-kvm1 \
--network network:default \
--accelerate \
--vnc \
--cdrom /iso/CentOS-5.5-x86_64-bin-DVD-1of2.iso

For network installation replace --cdrom with --location with URL to OS installation link.

Eg, Centos 5.6 64bit
--location http://mirror.its.sfu.ca/mirror/CentOS/5.6/os/x86_64/

Creating Scientific Linux 6 64bit vm with bridge networking and two virtual CPUs

Note: br0 bridge interface should exist before using it for KVM

virt-install --name kvm3 \
--ram 1024 \
--vcpus 2 \
--os-type='linux' \
--disk path=/dev/mapper/vg_kvm-kvm3 \
--network bridge:br0 \
--accelerate \
--vnc \
--location http://ftp1.scientificlinux.org/linux/scientific/6/x86_64/os/

*** Installing Slackware off NFS (NFS running on xxx.xxx.xxx.60 machine)

virt-install --name slack64 \
--ram 512 \
--vcpus 1 \
--os-type='linux' \
--disk path=/dev/mapper/vg_kvm-kvm8 \
--network bridge:br0 \
--accelerate --vnc \
--cdrom /iso/slackware_x86_64-13.37-mini-install.iso

Cloning KVM VM
1. LVM based
Cloning KVM (Create LVM partition for cloned first ie 'lvcreate -L 4G -n kvmX vg_kvm' run lvdisplay to check existing LVMs)
virt-clone --original kvm1 \
             --name kvmX \
              --file /dev/mapper/vg_kvm-kvmX --prompt

2. File based
virt-clone --original kvm1 \
             --name kvmX \
              --file /var/lib/libvirt/images/centos6-2.img

Resizing KVM VM disk storage
1. install libguestfs-tools package.
2. Best to have separate parititons for /, /boot, and swap, then following http://askaralikhan.blogspot.com/2011/07/expanding-kvm-guest-disk-image-using.html

Troubleshooting For network interface

1. Open /etc/sysconfig/network-scripts/ifcfg-eth0 and delete the following line and save the file
HWADDR=52:54:00:8f:62:01
2. Remove the following filen and reboot the virtual machine
/etc/udev/rules.d/*persistent-net*'
After reboot eth0 network interface will be available.

Removing LVM partition: Remove LVM partition which is no longer need.

# lvchange -an /dev/mapper/vg_kvm-kvm8 (change LVM status to inactive)
# lvremove /dev/mapper/vg_kvm-kvm8 (remove the LVM paritition)

Expanding a KVM guest disk image using virt-resize

2011-07-02T04:21:00.000-07:00

Decide on how you wish to expand the guest. Run virt-df -h and virt-list-partitions -lh on the guest disk, as shown in the following output:

# virt-df -h /dev/vg_kvm/kvm7
Filesystem                                Size       Used Available Use%
/dev/vg_kvm/kvm7:/dev/sda1              484.2M      48.8M     410.4M   11%
/dev/vg_kvm/kvm7:/dev/sda3               2.5G       1.3G      25.4G    5%

# virt-list-partitions -lh /dev/vg_kvm/kvm7
/dev/sda1 ext4 500.0M
/dev/sda2 swap 1.0G
/dev/sda3 ext4 2.5G

This example we will increase the size of /dev/sda3 to 30G

1. Shutdown guest

2. Rename the original disk for the backup purpose, for lvm use lvrename command, for file use 'mv' command

# lvrename /dev/vg_kvm/kvm7 /dev/vg_kvm/kvm7.backup
Renamed "kvm7" to "kvm7.backup" in volume group "vg_kvm"

3. Create new disk
# lvcreate -L 30G -n kvm7 vg_kvm
Logical volume "kvm7" created

4. Now resize the /dev/sda3, refer to virt-resize man for detail.

# virt-resize \

/dev/vg_kvm/kvm7.backup /dev/vg_kvm/kvm7 \

--expand /dev/sda3

Summary of changes:
/dev/sda1: partition will be left alone
/dev/sda2: partition will be left alone
/dev/sda3: partition will be resized from 2.5G to 28.5G
Copying /dev/sda1 ... done
Copying /dev/sda2 ... done
Copying /dev/sda3 ... done

Parition /dev/sda3 contains a filesystem or LVM PV, then this content is not automatically resized. You can resize it afterwards either using guestfish(1) (offline) or using commands inside the guest (online resizing).

Here we resize the filesystem using guestfish

[root@kvm ~]# guestfish -a /dev/vg_kvm/kvm7

Welcome to guestfish, the libguestfs filesystem interactive shell for
editing virtual machine filesystems.

Type: 'help' for help with commands
      'quit' to quit the shell

> run
> resize2fs /dev/sda3
libguestfs: error: resize2fs: resize2fs 1.41.12 (17-May-2010)
Please run 'e2fsck -f /dev/vda3' first.
> e2fsck-f /dev/sda3
> resize2fs /dev/sda3
> exit

[root@kvm ~]# virt-df -h sl6-5
Filesystem                                Size       Used Available Use%
sl6-5:/dev/sda1                         484.2M      48.8M     410.4M   11%
sl6-5:/dev/sda3                          28.1G       1.3G      25.4G    5%

Try to boot the virtual machine. If it works you can delete the backup disk.

# lvchange -an vg_kvm/kvm7.backup

# lvremove vg_kvm/kvm7.backup
Logical volume "kvm7.backup" successfully removed

Clone KVM with virt-clone

2011-07-02T00:44:00.000-07:00

virt-clone is a command line tool for cloning existing virtual machine images using the "libvirt" hypervisor management library. It will copy the disk images of any existing virtual machine, and define a new guest with an identical virtual hardware configuration. Elements which require uniqueness will be updated to avoid a clash between old and new guests

virt-clone of python-virtinst package is a great tool for creating cloned KVM virtual machine quickly.

Example: LVM based kvm

# virt-clone --original sl6-3 \
             --name sl6-4 \
              --file /dev/mapper/vg_kvm-kvm6 --prompt

In the above example /dev/mapper/vg_kvm-kvm6 LVM should be created before executing the virt-clone command.

Creating LVM
# lvcreate -L 4G -n kvm6 vg_kvm

Example file based storage
virt-clone \
              --original ubuntu11 \
              --name ubuntu-2 \
              --file /var/lib/libvirt/images/ubuntu-2.img

--original sl6-3 = name of the existing KVM (make sure the original KVM is shutdown before creating clone out of it)

--name se6-4 = Name of the New KVM (cloned)
--file = In LVM case path to the existing storage, in file based storage the file will be automatically created by virt-clone

Troubleshooting Network issue
Upon booting the new cloned KVM VM I encounter with problem of not showing any network interface. After digging more it appears that udev on virtual machine changed the eth0 interface with eth1 due to change in MAC of the interface. Quick search on Google suggested the following solution to get back the 'eth0' interface on cloned vm.

1. Open /etc/sysconfig/network-scripts/ifcfg-eth0 and delete the following line and save the file

HWADDR=52:54:00:8f:62:01

2. Remove the following filen and reboot the virtual machine

/etc/udev/rules.d/*persistent-net*'

After reboot eth0 network interface will be available.

Scientific Linux 6

2011-06-28T21:47:00.000-07:00

Recently I start using Scientific Linux on KVM virtual hosts. For anyone new to Scientific its a Enterprise Linux based on RHEL just like Centos maintained by Fermi National Accelerator Laboratory and the European Organization for Nuclear Research 'CERN' - and RHEL, of course :)

Scientific Linux folks is closely following the upstream srpm provider (RHEL) and its already shipped with version 6 just like RHEL 6.

The other things which inspired me to give a try to Scientific Linux is the latest version of Linux Kernel with latest hardware support, the ext4 filesystem is the default, KVM enhancement, latest versions of software eg PHP, Mysql which means I don't have to mess around with test repos or yum priorities

For detail What's new in RHEL/Scientific Linux please refer to RHEL.

I encourage anyone interested in RHEL and/or building your own test server, to experiment with this distro.

Medialess installation of Redhat Enterprise 6/Centos/Scientic Linux 6

2011-06-20T04:45:00.000-07:00

This procedure assumes you are already using Red Hat Enterprise Linux or another relatively modern Linux distribution, and the GRUB boot loader. It also assumes you are a somewhat experienced Linux user.

To perform medialess installation of Redhat Enterprise 6/Centos/Scientific Linux 6 without media or a PXE server, the system must have two files stored locally, a kernel and an initial RAM disk

Copy the vmlinuz and initrd.img files from a Red Hat Enterprise Linux DVD (or DVD image) to the /boot/ directory, renaming them to vmlinuz-install and initrd.img-install.

Editing the GRUB Configuration

The GRUB boot loader uses the configuration file /boot/grub/grub.conf. To configure GRUB to boot from the new files, add a boot stanza to /boot/grub/grub.conf that refers to them

title Installation
    root (hd0,0)
    kernel /boot/vmlinuz-install ip=xxx.xxx.xx.x netmask=255.255.255.0 gateway=xxx.xx.xx.x dns=xxx.xx.xx.x vnc vncpassword=qwerty repo=http://ftp1.scientificlinux.org/linux/scientific/6/x86_64/os/ lang=en_US keymap=us
    initrd /boot/initrd.img-install

If using network interface other than eth0 then you must have to specify it with ksdevice=ethX, then the kernel line will read something like this for eth1

kernel /boot/vmlinuz-install ip=xxx.xxx.xx.x netmask=255.255.255.0 gateway=xxx.xx.xx.x dns=xxx.xx.xx.x ksdevice=eth1 vnc vncpassword=qwerty repo=http://ftp1.scientificlinux.org/linux/scientific/6/x86_64/os/ lang=en_US keymap=us

The following options are generally useful for medialess installations:

IP = yourIP
netmas = Netmask
gateway = your Gateway
dns = your dns
vnc (for remote graphical installation)
vncpassword = Yourpassword
repo = Redhat/Centos/SL repo (In the sample I use the Scientific Linux 6 repo)

Also change the entry "default 0" to boot from new kernel entries, when done reboot the system.

Completing the installation:
From your local system use vncviewer to connect to the remote server and complete the installation process

$ vncviewer RemoteHostIP

KVM virt-install: Install Scientific Linux 6 (RHEL6) as KVM Guest

2011-06-19T23:56:00.000-07:00

Network installation of SL6 64bit as KVM guest.

virt-install --name se6 \
--ram 884 \
--os-type='linux' \
--disk path=/var/lib/libvirt/images/se6.img,size=10 \
--network network:default \
--accelerate \
--vnc \
--location http://ftp1.scientificlinux.org/linux/scientific/6/x86_64/os/

Connect from your local system to continue the installation

virt-viewer -c qemu+ssh://root@IPAdress/system se6

Installing skype on Fedora 14 64bit

2011-06-17T22:00:00.000-07:00

Skype only available for 32bit version of Fedora while most of the folks already get into wagon of 64bit OS, here is short howto installing the skype on 64bit Fedora. The hack is to install 32bit version of the following packages on 64bit Fedora.

yum install glibc.i686 alsa-lib.i686 libXv.i686 libXScrnSaver.i686 qt.i686 qt-x11.i686

Download Skype Fedora 13+ package from Skype official site http://www.skype.com/intl/en-us/get-skype/on-your-computer/linux/

And then install it.

yum install --nogpgcheck skype-2.1.0.81-fc10.i586.rpm

Hoping this is helpful

Upgrade to Fedora 14 using Preupgrade

2011-05-30T04:02:00.000-07:00

Few days back Fedora folks released Fedora 15, however I was still running Fedora 13 on my work laptop. So it was good time to upgrade before Fedora 13 become unsupported version.

Backup Backup Backup
Its recommended to backup your important stuff before going for online upgrade using preupgrade or yum to avoid any data loose in case of system goes to its knees :P

The Upgrade
Preupgrade is a nice tool for upgrading Fedora from one version to another, it can be run from GUI and also from CLI.

# preupgrade-cli "Fedora 14 (Laughlin)"

Depends on your Internet pipe it will takes quite some time to download all the required Fedora 14 packages, once packages successfully downloaded reboot is required to boot the system into Fedora 14 and complete the installation process of the packages.

Go get cup of tea while the installation process running. Once installation finished a final reboot and you will find your box booted into shiny Fedora 14.

Its was a clean upgrade, everything working fine after upgrade. Thumbs up for Fedora folks.

For detail please refer to Preupgrade wiki.

Note: I prefer not to go for Fedora 15 at this time due to the fuse around the Gnome 3, but will wait until the community find some solid solutions. I do not want to loose my desktop icons and application launchers ;)

Inserting colon after every 2nd digit using sed

2011-05-27T01:41:00.000-07:00

Sometime while working with the MAC address from BRAS I need to convert the MAC address into colon delimited. Here is how to insert colon after every second digit

Contents of mac.txt

00e04dc540fe
00e04dc541f6
00e04dc54366
00e04dc5452e
00e04dc543f6
00e04dc5473a
00e04dc54852
00e04dc54a9e
c8d5fe1fd02c
c8d5fe1fa69c

The command:
$ sed 's/../&:/g; s/:$//' < mac.txt

Result:
00:e0:4d:c5:40:fe
00:e0:4d:c5:41:f6
00:e0:4d:c5:43:66
00:e0:4d:c5:45:2e
00:e0:4d:c5:43:f6
00:e0:4d:c5:47:3a
00:e0:4d:c5:48:52
00:e0:4d:c5:4a:9e
c8:d5:fe:1f:d0:2c
c8:d5:fe:1f:a6:9c

Upgrade to CentOS 5.6 and KVM failure

2011-04-13T11:16:00.000-07:00

Recently I have upgraded my KVM server from Centos 5.5 to 5.6 I can no longer boot any of virtual machines. While trying to boot VM its gives error...

Booting from Hard Disk...
Boot failed: not a bootable disk
FATAL: No bootable device

My all VMs are qcow2 format, quick Googling reports its issue with the 'type=raw' in .xml file for the VM.

<driver name='qemu' type='raw'/>

Fixed:
Change the type='qcow2' in xml file, so that its read something like this

<driver name='qemu' type='qcow2'/>

And restart the libvirtd service.

This fixed all the KVM VMs for me.

Linux Tips and Tricks - Display the IPs on interfaces

2011-04-13T07:51:00.000-07:00

Using ifconfig

FIBER_ADDR=$(ifconfig $FIBER | grep 'inet addr' | sed 's/^[^:]\+://;s/$[^ \t]\+$.\+$/\1/')
echo $FIBER_ADDR

Same using IP command

ip addr show | awk '/inet[^6]/ { print $2 }' | sed -e 's/$.\+$\/.\+/\1/'

Find the disk space used by a user

2011-04-11T21:08:00.000-07:00

To find the disk space being used by a single user, you need to combine du with the find command to only report disk usage for a specific user:

$ find . -user username -type f -exec du -k {} \;

To get total disk used

$ find . -user username -type f -exec du -k {} \;|awk '{ s = s+$1 } END { print "Total used: ",s }'

You use the same principle with groups using the -group option to find

find . -group mcslp -type f -exec du -k {} \;|awk '{ s = s+$1 } END { print "Total used: ",s }'

Creating thumbnails on a fly using ImageMagick

2011-04-08T10:52:00.000-07:00

To create thumbnails for all the JPG files in the current directory

for img in *.jpg; do convert -resize 200 "$img" thumb_"$img";done

Linux Tips & Tricks

2011-04-07T10:39:00.000-07:00

Removing commented lines '#' from a file
grep -v '^#' squid.conf > squid.conf.new

to remove empty lines from a text file. I've been using sed with
sed '/^ *$/d' squid.conf.new > squid.conf.nospace

Do the same thing with sed in one line
sed '/^#/d' squid.conf.default | sed /^$/d > squid.conf.new

Or
sed -e '/^$#\|$$/ d' squid.conf.default > squid.conf.new

Remove comments and blank lines from a file
egrep -v '^(#|$)' squid.conf.default > squid.conf.new

Or
grep '^[^#]' squid.conf > squid.conf.new

2011 World Cup cricket ended in disappointment for Pakistan

2011-03-30T11:17:00.000-07:00

Long story short.......In electrifying semi final at MOHALI India beat Pakistan by 29 runs on Wednesday to set-up a World Cup final against Sri Lanka in Mumbai on Saturday.

The 100 Oldest Currently Registered .COM Domains

2011-03-18T23:12:00.000-07:00

Here is the list of 100 oldest .com domains if anyone wondering to buy any of the these domain eg sun.com (the 12th oldest domain) which Oracle will soon spare after $7 billion purchase of Sun Microsystems. then remember you need a bottom less pocket :).
Domain brokers speculate Oracle could sell it for $1 million or more, if it chose to do so.

My Baby Girl Fatime

2011-03-15T22:33:00.000-07:00

If anyone wondering about my baby girl Fatime here she :). Fatima is now almost two months old.

Its more fun with Ayesha and Fatima I would say its the greatest time of our lives.

Installing oracle-instantclient on Centos 5.5

2011-03-11T01:21:00.000-08:00

1. Download oracle instantclient rpm from Oracle for your platform

Need to download these two rpms.

oracle-instantclient-basic-*
oracle-instantclient-devel-*

2. Install
# rpm -ivh oracle-instantclient-*

Getting and compiling oci8 extension for PHP

# pear download pecl/oci8
# tar zxvf oci8-1.4.5.tgz
# cd oci8-1.4.5
# ./configure --with-oci8=instantclient
# make
# make install

Create a file called /etc/php.d/oracle_oci.ini and place the following line
extension=oci8.so

Restart Apache

Create a .php file with call to phpinfo(); and confirm that oci8 is loaded in apache, you can also check if module is loaded with php -m.

HP EliteBook 8540p Hibernate/Suspend Fixed in Fedora 13

2011-03-09T10:53:00.000-08:00

Today got time to play with the long standing problem of hibernate/suspend problem on my work notebook HP EliteBook 8540p running Fedora 13 (upgrading to Fedora 14 still pending :( )

Quick Google search reports an article on The Linux Laptop Wiki and astonishingly within 3 minutes the problem fixed and now the thing goes on suspend/hibernate (as per power management settings) if the laptop lid is closed while on battery power or when when the battery power is critically low.

As per the article all have to do is to create a script,

1. Create a script file.
$ sudo vi /etc/pm/sleep.d/01fix_usb3

#!/bin/sh
# Put the laptop to suspend/hibernate
MOD=xhci-hcd

case $1 in
suspend | hibernate) modprobe -r $MOD ;;
resume | thaw) modprobe $MOD ;;
*) echo "USB3 fix script: wrong argument $1" ;;
esac

2. Make it executable
sudo chmod +x /etc/pm/sleep.d/01fix_usb3

Thanks to nice folks at The Linux Laptop Wiki.

Update: This hack is no longer required in Fedora 14, Hibernate/Suspend working out of the box in Fedora 14

Bulk data uploading into the Oracle database using SQL*Loader

2011-03-02T23:34:00.000-08:00

SQL*Loader is a bulk loader utility used for moving data from external files into the Oracle database.

SQL*Loader (sqlldr) is the utility to use for high performance data loads. The data can be loaded from any text file and inserted into the database.

Recently I got the chance to use SQL*Loader to automate data uploading from a text file in which each field delimited with the pipe "|" into the Oracle.

1. Create a control file, call it anything in my case its add.ctl

load data infile '-'
APPEND
into table records
fields terminated by '|'
(
field1,
field2,
.
.
fieldN
)

load data infile '-' : In my case there are multiple text files which to be process by sqlldr so instead of using filename I used the '-'. And used APPEND to append the new data into the table.

2. Script to run to call sqlldr utility for uploading the data from text files.

#!/bin/sh
# Author: Askar Ali Khan
# Purpose: To upload data from text files into Oracle Table - RECORDS
# records_upload

# Define Oracle variables
ORACLE_BASE=/oracle
ORACLE_HOME=$ORACLE_BASE/102
ORACLE_SID=SID
LD_LIBRARY_PATH=$ORACLE_HOME/lib
PATH=$PATH:$ORACLE_HOME/bin
export ORACLE_BASE ORACLE_HOME ORACLE_SID LD_LIBRARY_PATH PATH

SRCDIR="/data"

# Must be run as oracle user
if [[ $UID -ne 501 ]]; then
echo "$0 must be run as oracle"
exit 1
fi

cd "$SRCDIR"

# If directory contains *.txt files then call sqlldr otherwise do nothing

for file in *.txt; do
test -f "$file" || continue
cat $file | sqlldr oraclUser/Password add.ctl
rm -f $file
done

The script process files in /data directory one by one by piping into sqlldr and delete it. Deletion is must coz in the next run there will be new files fetched into /data directory by another FTP script.

3. Define a cron job under oracle user to run script every 15 minutes

$ crontab -e
*/15 * * * * /usr/local/bin/records_upload > /dev/null 2>&1

Backup using Rsync

2011-03-02T22:51:00.000-08:00

Rsync is a great tool for backup your servers, home directories or anything else, I thought of go for a little howto but there is already plenty of material available online therefore no need to reinvent the wheel :)

Anyone interested in quick howto for Rsync I would suggest to look into very nice article on LinuxPlanet.

Screencasting in Linux

2011-02-28T01:19:00.000-08:00

To create screencast in Linux there lots of Open Source applications but I found RecordMyDesktop the easiest one to use.

Installing of recordmydeskop is straight forward under most of Linux distributions and there is a chance that its available in your Linux distro repository.

Installing on Fedora 13

sudo yum install gtk-recordmydesktop

Or prefer to install QT based which is the fork of gtk based then,

sudo yum install qt-recordmydesktop

Using recordmydesktop is very easy and its do not require any explanation, but still interested in learning more about then refer to recordmydesktop documentions.

Installing Oracle 11gR2 on Centos 5.5 64bit

2011-02-13T21:02:00.000-08:00

1. The /etc/redhat-release should be faked to show Red Hat Enterprise Linux Server release 5 (Tikanga). same goes for /etc/issues file.
But to be sure apply this settings (backup /etc/redhat-release and /etc/issue before) change existing value to
Red Hat Enterprise Linux Server release 5 (Tikanga)

2. Install fake redhat-release RPM file from http://ivan.kartik.sk/

rpm -i centos-fake.noarch.rpm

3. Create Required UNIX Groups and User (For detail check http://download.oracle.com/docs/html/B15521_01/toc.htm)

# /usr/sbin/groupadd oinstall
# /usr/sbin/groupadd dba

# /usr/sbin/useradd -g oinstall -G dba oracle

Enter the following command to set the password of the oracle user:

# passwd oracle

4. Create Required Directories
Create directories with names similar to the following and specify the correct owner, group, and permissions for them:

    * /u01/app/oracle (the Oracle base directory)
    * /u02/oradata (an optional Oracle datafile directory)

# mkdir -p /u01/app/oracle
# mkdir -p /u02/oradata

#

Change the permissions on the directories that you created to 775:

# chmod -R 775 /u01/app/oracle
# chmod -R 775 /u02/oradata

Depending on the oracle user's default shell, make the following changes to the default shell start-up file:

    * For the Bourne, Bash, or Korn shell, add the following lines to the /etc/profile file (or the /etc/profile.local file on SUSE systems):

      if [ $USER = "oracle" ]; then
              if [ $SHELL = "/bin/ksh" ]; then
                    ulimit -p 16384
                    ulimit -n 65536
              else
                    ulimit -u 16384 -n 65536
              fi
      fi

Fulfilling package requirements:

       kernel-headers-2.6.18-194.el5.x86_64.rpm \
           glibc-headers-2.5-49.x86_64.rpm \
           glibc-devel-2.5-49.x86_64.rpm \
           libstdc++-devel-4.1.2-48.el5.x86_64.rpm \
           compat-db-4.2.52-5.1.x86_64.rpm \
           libgomp-4.4.0-6.el5.x86_64.rpm \
           gcc-4.1.2-48.el5.x86_64.rpm \
           gcc-c++-4.1.2-48.el5.x86_64.rpm \
           sysstat-7.0.2-3.el5.x86_64.rpm \
           unixODBC-2.2.11-7.1.x86_64.rpm \
           unixODBC-devel-2.2.11-7.1.x86_64.rpm \
           libXp-1.0.0-8.1.el5.i386.rpm \
           libstdc++-devel-4.1.2-48.el5.i386.rpm \
           unixODBC-2.2.11-7.1.i386.rpm \
           unixODBC-devel-2.2.11-7.1.i386.rpm \
           libaio-devel-0.3.106-5.x86_64.rpm \
           elfutils-libelf-devel-static-0.137-3.el5.x86_64.rpm \
           elfutils-libelf-devel-0.137-3.el5.x86_64.rpm \
           compat-gcc-34-3.4.6-4.x86_64.rpm \
           compat-gcc-34-c++-3.4.6-4.x86_64.rpm \
           gdb-7.0.1-23.el5.x86_64.rpm \
           libtermcap-devel-2.0.8-46.1.x86_64.rpm \
           readline-devel-5.1-3.el5.x86_64.rpm \
           glibc-devel-2.5-49.i386.rpm \
           libaio-devel-0.3.106-5.i386.rpm

Install Oracle Database 11gR2

1. Download the linux.x64_11gR2_database_1of2.zip and linux.x64_11gR2_database_2of2.zip from www.oracle.com
2 unzip both archive this will give one database directory
3. cd database directory and run ./runInstaller (the installer must be run as oracle user)

Installing KVM guest using virt-install tool

2011-02-01T02:45:00.000-08:00

These has been tested on Centos 5.5 64bit host.

1. KVM Guest installation with virt-install using default networking and storage image created automatically.

virt-install \
     --name ubuntu_server \
     --ram 256 \
     --disk path=/var/lib/libvirt/images/ubuntu_server.img,size=5 \
     --network network:default \
     --accelerate \
     --vnc \
     --cdrom FullPathTo.iso

2. KVM Guest installation with virt-install using bridging interface, and storage image file created with qemu-img

For this its assume that bridge 'br0' interface is already configured on host, refer to how to create bridge interface on Redhat/Centos.

a) To create storage image
# qemu-img create -f qcow2 /var/lib/libvirt/images/ubuntu_server.img 10G

b)
virt-install \
     --name ubuntu_server \
     --ram 256 \
     --os-type='linux' \
     --disk path=/var/lib/libvirt/images/ubuntu_server.img \
     --network bridge:br0 \
     --accelerate \
     --vnc \
     --cdrom FullPathTo.iso

3. Install a KVM in text mode from remote http server, storage image created with qemu-img. Check (a) for creating storage image

virt-install \
              --name centos2 \
              --ram 256 \
              --os-type='linux' \
              --disk path=/var/lib/libvirt/images/centos2.img \
              --network network:default \
              --nographics \
              --location http://mirror.switch.ch/ftp/mirror/centos/5.5/os/x86_64/ \
              --hvm \
              --extra-args console=ttyS0

Note: --extra-args will only work when performing a guest install from "--location", when doing install from local ISO image it should be mounted somewhere

Tips for completing the installing of guest operating system

1) To Connect from remote PC/laptop

1. install virt-viewer on your local pc

2. Upload your ssh public key to KVM host /root/.ssh/authorized_keys (For this you should allow root login in /etc/ssh/sshd_config)

3. Run the following by replace KVMHostIP with KVM host IP address and vmName with the KVM virtual machine name.

$ virt-viewer -c qemu+ssh://root@KVMHostIP/system vmName

To connect KVMs from the KVM Host

To connect using the virt-viewer tool, run the following command:
# virt-viewer vmName

To connect using the virt-manager tool, run the following command:
# virt-manager vmName

Auto start KVM VMs on Host system boot

The following command will mark the VM for auto start on system reboot

# virsh autostart vmName

Creating KVM Guests using virsh tool

2011-01-30T22:24:00.000-08:00

An example XML file to install an operating system from an ISO image The following example XML file can be modified to create a KVM and boot to any operating system from an ISO image or a CD-ROM drive.

<domain type='kvm'>
   <name>kvm1</name>
   <uuid>a1e40383-2dfb-47f7-9cf6-589fc9679aa7</uuid>
   <memory>524288</memory>
   <currentMemory>524288</currentMemory>
   <vcpu>1</vcpu>
   <os>
     <type arch='x86_64' machine='pc'>hvm</type>
     <boot dev='cdrom'/>
 </os>
 <features>
    <acpi/>
    <apic/>
     <pae/>
 </features>
 <clock offset='localtime'/>
 <on_poweroff>destroy</on_poweroff>
 <on_reboot>restart</on_reboot>
 <on_crash>restart</on_crash>
 <devices>
     <emulator>/usr/libexec/qemu-kvm</emulator>
     <disk type='file' device='disk'>
       <source file='/var/lib/libvirt/images/kvm1.img'/>
       <target dev='hda' bus='ide'/>
     </disk>
    <disk type='file' device='cdrom'>
     <source file='/home/askarali/.bb/Fedora-14-x86_64-Live/Fedora-14-x86_64-Live-Desktop.iso'/>
     <target dev='hdc' bus='ide'/>
     <readonly/>
     </disk>
     <interface type='network'>
      <mac address='54:52:00:2a:58:0d'/>
      <source network='default'/>
    </interface>
     <input type='mouse' bus='ps2'/>
     <graphics type='vnc' port='-1' autoport='yes' keymap='en-us'/>
 </devices>
 </domain>

Edit the following before proceeding
a) Each guest needs a universal unique identifier (uuid), You must generate one for your guest by running the following command, and then copy and paste the identifier into the XML file <uuid>HERE</uuid>

# uuidgen

b) Replace <memory>524288</memory> and <currentMemory>524288</currentMemory> tag to memory you want to allocate to your guest.

c) Replace <mac address='54:52:00:2a:58:0d'/> with the mac address, To generate unique mac address, get the python script from http://www.centos.org/docs/5/html/5.2/Virtualization/sect-Virtualization-Tips_and_tricks-Generating_a_new_unique_MAC_address.html

Creating Storage Image file
# qemu-img create -f qcow2 /var/lib/libvirt/images/kvm1.img 10G

Using virsh to create a KVM
1. Define your KVM by running:
# virsh define kvm1.xml

2. Start the KVM so that the installation of its operating system can begin:
# virsh start kvm1

If your KVM does not start, complete one of the following to redefine the KVM:

# virsh edit <Name of KVM>

After editing the definition file, try to start guest vm again

# virsh start vmName

Tips for installing your guest operating system (This should be run on mother host

To Connect from your PC/laptop

1. install virt-viewer
2. Upload your ssh public key to KVM host /root/.ssh/authorized_keys (For this you should allow root login in /etc/ssh/sshd_config)

From your laptop, run

$ virt-viewer -c qemu+ssh://root@KVMHostIP/system vmName

To connect KVMs from the Host

To connect using the virt-viewer tool, run the following command:
# virt-viewer vmName

To connect using the virt-manager tool, run the following command:
# virt-manager vmName

Editing the KVM definition file after operating system installation

To boot to the installed guest after the guest operating system installation is complete, revise the guest
definition so that it will boot from its hard disk drive.

# virsh edit vmName

1. Replace <boot dev='cdrom'/> line with <boot dev='hd'/> (To boot from hard disk)
2. and remove the ISO disk definitions are removed because they are no longer needed.

Propagating your KVMs
For example, if your task is to create 10 identical KVMs that have simple configurations, you can propagate existing KVMs rather than manually installing 10 identical KVMs.

1. Stop the template KVM with the virsh tool:

# virsh shutdown templateKVM

2. Make copies of the KVM disk image by using the qemu-image command with the convert option:

# qemu-img convert templateKVM.img -O qcow2 NewKVM1.img

3. Make copies of the templateKVM XML definition file. You can find it in the /etc/libvirt/qemu/directory or you can run the following command to see the definition file.

# virsh dumpxml templateKVM

4. Edit the definition files for name, memory, mac address, source file etc to define the new KVMs. It is important that a unique MAC address is used in the definition file to make sure that the network functions without a problem.

Networking in Bridge Mode

1. Configure the bridge interface on host operating system
2. replace <interface type='network'> section in kvm.xml with the following

<interface type='bridge'>
<mac address='00:16:3e:56:40:ad'/>
<source bridge='br0'/>
</interface>

3. Install the guest OS, after installation configure the IP on guest.

Auto start KVM VMs on Host system boot

The following command will mark the VM for auto start on system reboot

# virsh autostart vmName

VirtualBox 4.0: Creating a Virtual Machine on a headless server

2011-01-13T00:06:00.000-08:00

The following instructions may give you an idea how to create a virtual machine on a headless server over a network connection. We will create a virtual machine, establish an RDP connection and install a guest operating system -- all without having to touch the headless server. All you need is the following:

1. VirtualBox on a server machine with a supported host operating system. The VirtualBox extension pack for the VRDP server must be installed For the following example, we will assume a Linux server.

2. An ISO file accessible from the server, containing the installation data for the guest operating system to install (we will assume Windows XP in the following example).

3. A terminal connection to that host through which you can access a command line (e.g. via ssh).

4. An RDP viewer on the remote client rdesktop, rdesktop-vrdp, Microsoft mstsc

Note again that on the server machine, since we will only use the headless server, neither Qt nor SDL nor the X Window system will be needed.

1. On the headless server, create a new virtual machine:

VBoxManage createvm --name "Windows XP" --ostype WindowsXP --register

Note that if you do not specify --register, you will have to manually use the registervm command later.

Note further that you do not need to specify --ostype, but doing so selects some sane default values for certain VM parameters, for example the RAM size and the type of the virtual network device. To get a complete list of supported operating systems you can use

VBoxManage list ostypes

2. Make sure the settings for this VM are appropriate for the guest operating system that we will install. For example:

VBoxManage modifyvm "Windows XP" --memory 256 --acpi on --boot1 dvd --nic1 nat

3. Create a virtual hard disk for the VM (in this case, 10GB in size):

VBoxManage createhd --filename "WinXP.vdi" --size 10000

4. Add an IDE Controller to the new VM:

VBoxManage storagectl "Windows XP" --name "IDE Controller" --add ide --controller PIIX4

5. Set the VDI file created above as the first virtual hard disk of the new VM:

VBoxManage storageattach "Windows XP" --storagectl "IDE Controller" --port 0 --device 0 --type hdd --medium "WinXP.vdi"

6. Attach the ISO file that contains the operating system installation that you want to install later to the virtual machine, so the machine can boot from it:

VBoxManage storageattach "Windows XP" --storagectl "IDE Controller" --port 0 --device 1 --type dvddrive --medium /full/path/to/iso.iso

7. Start the virtual machine using VBoxHeadless:

VBoxHeadless --startvm "Windows XP"

If everything worked, you should see a copyright notice. If, instead, you are returned to the command line, then something went wrong.

8. On the client machine, fire up the RDP viewer and try to connect to the server (see the section called “Common third-party RDP viewers” above for how to use various common RDP viewers).

You should now be seeing the installation routine of your guest operating system remotely in the RDP viewer.

To stop a VM
VBoxManage controlvm "Windows XP" poweroff

To pause a VM
VBoxManage controlvm "Windows XP" pause

Allow multi connections:
VBoxManage modifyvm "Windows XP" --vrdemulticon on

Listen on different port
VBoxHeadless --startvm "Windows XP" --vrdeproperty "TCP/Ports"=5001

Installing Guest Addition on Headless VM

1. First attach the Guest Addition .iso to VM (vm should be poweroff)

VBoxManage storageattach "Windows XP" --storagectl "IDE Controller" --port 1 --device 0 --type dvddrive --medium /usr/share/virtualbox/VBoxGuestAdditions.iso

2. Start VM and now you can explorer and install the guest addition.

VirtualBox VBoxHeadless, the remote desktop server

2011-01-12T22:46:00.000-08:00

Which produces no visible output on the host at all, but instead only delivers VRDP data. This front-end has no dependencies on the X Window system on Linux and Solaris hosts, this is usefull on servers where the only purpose is to run VMs and access it remotely.

Prerequisite:
On Virtualbox 4.0 you must have extension pack installed.

To start a virtual machine with VBoxHeadless, you have two options:

VBoxManage startvm "VM name" --type headless

The extra --type option causes VirtualBox to use VBoxHeadless as the front-end to the internal virtualization engine instead of the Qt front-end.

The alternative is to use VBoxHeadless directly, as follows:

VBoxHeadless --startvm

This way of starting the VM is preferred because you can see more detailed error messages, especially for early failures before the VM execution is started. If you have trouble with VBoxManage startvm, it can help greatly to start VBoxHeadless directly to diagnose the problem cause.

Note that when you use VBoxHeadless to start a VM, since the headless server has no other means of output, the VRDP (VirtualBox Remote Desktop Protocol) server will always be enabled, regardless of whether you had enabled the VRDP server in the VM's settings

Accessing the VM remotely:

On Linux host you can test the Remote display of VM using rdesktop, or rdesktop-vrdp which is installed with VirtualBox

rdesktop -a 16 -N 1.2.3.4:3339

As said for the Microsoft viewer above, replace "1.2.3.4" with the host IP address, and 3389 with a different port if necessary. The -a 16 option requests a color depth of 16 bits per pixel, which we recommend. (For best performance, after installation of the guest operating system, you should set its display color depth to the same value). The -N option enables use of the NumPad keys.

rdesktop-vrdp 127.0.0.2:3339

When connecting to localhost in order to test the connection, the addresses localhost and 127.0.0.1 might not work. Instead, the address 127.0.0.2[:3389] has to be used.

On Windows, you can use the Microsoft Terminal Services Connector (mstsc.exe) that ships with Windows. You can start it by bringing up the "Run" dialog (press the Windows key and "R") and typing "mstsc". You can also find it under "Start" -> "All Programs" -> "Accessories" -> "Remote Desktop Connection". If you use the "Run" dialog, you can type in options directly:

mstsc 1.2.3.4[:3389]

VirtualBox Remote display (VRDP support)

2011-01-12T22:35:00.000-08:00

VirtualBox can display virtual machines remotely, meaning that a virtual machine can execute on one machine even though the machine will be displayed on a second computer, and the machine will be controlled from there as well, as if the virtual machine was running on that second computer.

Prerequisites:
VirtualBox Extentions Pack

You can also check my eariier post for how to install VirtualBox and extention pack.

Enabling VRDP

Even when the extension is installed, the VRDP server is disabled by default. It can easily be enabled on a per-VM basis either in the VirtualBox Manager in the "Display" settings or with VBoxManage:

VBoxManage modifyvm "VM name" --vrde on

By default, VRDP uses TCP port 3389. You will need to change the default port if you run more than one VRDP server, since the port can only be used by one server at a time; you might also need to change it on Windows hosts since the default port might already be used by the RDP server that is built into Windows itself. Ports 5000 through 5050 are typically not used and might be a good choice.

Accessing the VM remotely:

On Linux host you can test the Remote display of VM using rdesktop, or rdesktop-vrdp which is installed with VirtualBox

rdesktop -a 16 -N 1.2.3.4:3339

As said for the Microsoft viewer above, replace "1.2.3.4" with the host IP address, and 3389 with a different port if necessary. The -a 16 option requests a color depth of 16 bits per pixel, which we recommend. (For best performance, after installation of the guest operating system, you should set its display color depth to the same value). The -N option enables use of the NumPad keys.

rdesktop-vrdp 127.0.0.2:3339

When connecting to localhost in order to test the connection, the addresses localhost and 127.0.0.1 might not work using mstsc.exe. Instead, the address 127.0.0.2[:3389] has to be used.

On Windows, you can use the Microsoft Terminal Services Connector (mstsc.exe) that ships with Windows. You can start it by bringing up the "Run" dialog (press the Windows key and "R") and typing "mstsc". You can also find it under "Start" -> "All Programs" -> "Accessories" -> "Remote Desktop Connection". If you use the "Run" dialog, you can type in options directly:

mstsc 1.2.3.4[:3389]

Installing VirtualBox 4.0 on Fedora 13

2011-01-11T22:21:00.000-08:00

Oracle recently released VirtualBox 4.0, a new major release. It now has an open architecture using extension packs and the base package is under GPLv2 and lots of new cool features. So its worth to install the VB 4.0

This article assume that you have already older version of VirtualBox installed along with all the dependencies.

1. First install the DKMS package

$ sudo yum install dkms

2. Download the VB 4.0 for Fedora 13 64bit

$ wget http://download.virtualbox.org/virtualbox/4.0.0/VirtualBox-4.0-4.0.0_69151_fedora13-1.x86_64.rpm

3. Uninstall the older version of VB (make sure no virtual machine is running)

$ rpm -qa | grep VirtualBox <- this will give you the package name of installed VB

$ sudo rpm –e PackageName (replace package name with the name got from earlier command)

4. Install VirtualBox 4.0

sudo rpm –Uvh VirtualBox-4.0-4.0.0_69151_fedora13-1.x86_64.rpm

Download and install the extension pack as follows:

$ wget http://download.virtualbox.org/virtualbox/4.0.0/Oracle_VM_VirtualBox_Extension_Pack-4.0.0-69151.vbox-extpack

$ sudo VBoxManage extpack install Oracle_VM_VirtualBox_Extension_Pack-4.0.0-69151.vbox-extpack

Receiving SNMP Traps in Nagios

2010-12-22T20:57:00.000-08:00

SNMP traps are alerts and notifications generated by SNMP-enabled devices. The traps con-tain information about the status or an event on an SNMP-enabled device. For example, an authentication event or the change in status of an interface on a router may generate an SNMP trap that is sent to a management station of some sort, such as HP OpenView, CiscoWorks, Nagios.

Pre-requisites:

1. Net-SNMP with snmptrapd configured.
2. SNMPTT, SNMP trap translator.
3. Nagios.
5. Mib definition files for the equipment or software you need to monitor.

Installing Net-SNMP packages:

The Net-SNMP package is available as a series of installable packages on many distributions. Indeed, it may already be installed on your system or you may be able to install it via your distribution’s package management system, such as yum, apt, or the like. On Red Hat, SuSE, Debian, and Mandrake
distributions, the required packages are called net-snmp, net-snmp-libs, and net-snmp-utils.

Installing Net-SNMP packages on Centos 5.5

# yum install net-snmp net-snmp-libs net-snmp-utils net-snmp-perl perl-Net-SNMP net-snmp-devel

Configuring and Running the snmptrapd Daemon
When incoming traps are received from the snmptrapd daemon, they are passed to the SNMPTT tool. The SNMPTT tool will then try to match the incoming trap against the collection of trap definitions that it has translated. If the trap matches, SNMPTT will see if the translated trap definition contains logic to output it to Nagios and execute that logic. The trap is then out-put to Nagios as a passive check result.

On Centos 5.5

# vi /etc/sysconfig/snmptrapd.options
#OPTIONS="-On -Lsd -c /etc/snmp/snmptrapd.conf -p /var/run/snmptrapd.pid"
OPTIONS="-On -Lsd -p /var/run/snmptrapd.pid"

Make sure to remove the -c /etc/snmp/snmptrapd.conf part, otherwise you will receive TRAP twice, as snmptrapd' is compiled with the default configuration file path being already set to '/etc/snmp/snmptrapd.conf'.

As quoted from SNMP Trap Translator documentation: "The -On is recommended. This will make snmptrapd pass OIDs in numeric form and prevent SNMPTT from having to translate the symbolic name to numerical form."

# vi /etc/snmp/snmptrapd.conf
traphandle default /usr/sbin/snmptthandler
disableAuthorization yes
#donotlogtraps yes

The traphandle directive tells the snmptrapd daemon how to handle incoming traps and where to send them. Adding the default option tells the daemon that this is the default way to handle all incoming traps. All traps will be sent to the snmptthandler script located in the /usr/sbin directory, the "disableAuthorization yes" tells to accept SNMP traps from all you can configure it to do authentication for detail refer to snmptrapd.conf manual.

Installing SNMPTT (SNMP Trap Translator)
You can get the SNMPTT tool from Sourceforge at http://snmptt.sourceforge.net/. This line shows how to download and unpack the SNMPTT tool:
Download snmptt_1.3.tgz which the latest version/stable release.

tar -zxvf snmptt_1.3.tgz

The SNMPTT package has no installation script, so a number of manual installations steps need to take place. First, copy the SNMPTT binaries to a suitable directory and mark them as executable. I recommend using the /usr/sbin directory

# cp snmptt snmptthandler /usr/sbin/
# chmod +x /usr/sbin/snmptt /usr/sbin/snmptthandler

I specified the snmptthandler binary as the value of the traphandle option in the snmptrapd.conf configuration file in the previous section. When a trap is received, this binary is executed by default and the trap sent to the snmptt daemon

Next, copy the SNMPTT configuration file, snmptt.ini, to the /etc/snmp directory and snmpttconvertmib utility

# cp snmptt.ini /etc/snmp/
# cp snmpttconvertmib /usr/sbin/

Also needed are a user and group to run the SNMPTT daemon as.

# groupadd snmptt
# adduser -g snmptt snmptt

# chown snmptt:snmptt /etc/snmp/snmptt.ini

The SNMPTT tool also needs a spool directory to hold the incoming traps. I usually use the default directory of /var/spool/snmptt. It needs to be owned by the user and group that will run SNMPTT. Create and change the ownership of the directory like so

# mkdir /var/spool/snmptt
# chown snmptt:snmptt /var/spool/snmptt

Finally, in order to start the SNMPTT tool, you can either execute it from the command line or use the init script provided with the package. On the following line

SNMPTT started in daemon mode:
# /usr/sbin/snmptt -daemon

Or copy the init script provided with the package, you can then add it to your startup process.

# cp snmptt-init.d /etc/init.d/snmptt

To start/stop/reload you can do with ..

/etc/init.d/snmptt start/stop/reload

Configuring SNMPTT
The first is configuring the /etc/snmp/snmptt.ini file. The file contains quite a large number of directives, but I’ll only look at those relevant to the process of translating and transmitting the received traps to Nagios

mode = daemon
daemon_fork = 1
daemon_uid = snmptt
spool_directory = /var/spool/snmptt/
sleep = 5
dns_enable = 1
strip_domain = 1
log_enable = 1
syslog_enable = 0
exec_enable = 1
snmptt_conf_files = <
/etc/snmp/snmptt.conf
END

The sample snmptt.ini file contained in the SNMPTT package has detailed explanations of all the directives and options that you can specify. I recommend reading this file for further information and explanations about SNMPTT’s configuration options

Tip: If you enable DNS resolution, I recommend you add all the hostnames that need to be resolved to the local /etc/hosts file on your host server. This prevents your DNS server from being a bottleneck or preventing SNMPTT from functioning if your DNS server is unavailable.

Compiling MIBs
You must gather all MIBs for monitored software, so you can feed SNMPTT with them. Compiling consists in extracting each OID of type "trap" and its associated comments, and generate a configuration file in SNMPTT format from these informations.

Run the following command on each of your MIB files:

snmpttconvertmib --in= --out=/etc/snmp/snmptt.conf. \
--exec='/usr/local/nagios/libexec/eventhandlers/submit_check_result $r TRAP 1'

The resulting SNMPTT configuration file will contain blocks (one per selected OID)

Catchall Trap Definition
SNMPTT also has a regular expression–matching capability that allows you to use an EVENT line that matches multiple incoming traps, a catchall trap definition. This means you don’t need to define individual translated trap definitions for each possible incoming trap.

Catchall Trap Definition
EVENT CatchAll .1.* "SNMP Traps" Critical
FORMAT $D
EXEC /usr/local/nagios/libexec/eventhandlers/submit_check_result "$r"
"snmp_traps" 2 "$O: $1 $2 $3 $4 $5"

I could also be more selective and select OIDs from a particular vendor or class of trap either using a wildcard or regular expression pattern matching. I’ve added a category called SNMP Traps and severity of Warning.

For example here is example to catchall traps from a specific vendor OID.

EVENT CatchAll .1.3.6.1.4.1.20916.* "Status Events" Normal
FORMAT A room-alert-4e-snmp-trap indicates that an alarm $*
EXEC /usr/lib/nagios/plugins/eventhandlers/submit_check_result $r "snmp_traps" 1 "A room-alert-4e-snmp-trap indicates that an alarm $*"
SDESC
A room-alert-4e-snmp-trap indicates that an alarm
condition has occurred on the sensor indicated
by the alarmmessage variable.
Variables:
1: alarmmessage
EDESC

When done, add to SNMPTT configuration file /etc/snmp/snmptt.ini the path to compiled configuration files:

[...]
snmptt_conf_files = <
/etc/snmp/snmptt.conf.
/etc/snmp/snmptt.conf.
END

Configuring Nagios
You will use passive checks to receive SNMP traps but they also will be volatiles. If ever two traps are received from the same host, the second one coming in before the first one was reset to OK, we want to be notified twice, although there is no state change. That's why we use a volatile service.

You might define (for example) a service template for SNMP traps, inheriting from a generic service template:

define service{
        name                            generic-service
        active_checks_enabled           1
        passive_checks_enabled          1                       ; Passive service checks are enabled/accepted
        parallelize_check               1
        obsess_over_service             1
        check_freshness                 0
        notifications_enabled           1                       ; Service notifications are enabled
        event_handler_enabled           1                       ; Service event handler is enabled
        flap_detection_enabled          1                       ; Flap detection is enabled
        failure_prediction_enabled      1                       ; Failure prediction is enabled
        process_perf_data               1                       ; Process performance data
        retain_status_information       1                       ; Retain status information across program restarts
        retain_nonstatus_information    1                       ; Retain non-status information across program restarts
        is_volatile                     0                       ; The service is not volatile
        check_period                    24x7                    ; The service can be checked at any time of the day
        max_check_attempts              3                       ; Re-check the service up to 3 times in order to determine its final (hard) state
        normal_check_interval           10                      ; Check the service every 10 minutes under normal conditions
        retry_check_interval            2                       ; Re-check the service every two minutes until a hard state can be determined
        contact_groups                  admins                  ; Notifications get sent out to everyone in the 'admins' group
        notification_options            w,u,c,r                 ; Send notifications about warning, unknown, critical, and recovery events
        notification_interval           60                      ; Re-notify about service problems every hour
        notification_period             24x7                    ; Notifications can be sent out at any time
         register                        0                      ; DONT REGISTER THIS DEFINITION - ITS NOT A REAL SERVICE, JUST A TEMPLATE!
        }

define service{
name                    trap-service
use                     generic-service
register                0
service_description     snmp_traps
is_volatile             1
check_command           check-host-alive    ;Used to reset the status to OK when 'Schedule an immediate check of this service' is selected.
flap_detection_enabled 0                               ; Flap detection is disabled
process_perf_data       0                               ; Do not Process performance data
max_check_attempts      1                    ; Leave as 1
normal_check_interval   1                    ; Leave as 1
retry_check_interval    1                    ; Leave as 1
passive_checks_enabled 1                    ; Enables passive checks
check_period            24x7
notification_interval   31536000                ; Notification interval. Set to a very high number to prevent you from getting                                 pages of previously received traps (1 year - restart Nagios at least once a year! -                                     do not set to 0!).
active_checks_enabled   0                    ; Prevent active checks from occuring as we are only using passive checks.
notification_options    w,u,c                    ; Notify on warning, unknown and critical.
contact_groups          sysadmins
}

define service{
host_name       AVT-Room-Alert ; hostname is define /etc/hosts file
use             trap-service
contact_groups sysadmins
}

TIP: You could also use a wildcard to create this service for all hosts or use the hostgroup_name directive to create the service for all members of a host group or groups.

I’ve defined the service as volatile and set the maximum check attempts to 1. This will cause Nagios to immediately set a HARD service state and trigger any configured notifications or event handlers. I’ve also configured it for passive checks only and disabled active checks.

Putting It All Together
The SNMPTT tool is called via the trap handler defined in the snmptrapd.conf configuration file I defined in the “Configuring and Running the snmptrapd Daemon” section. This trap handler calls the /usr/sbin/snmptthandler script. The script reads the trap and then writes it to the spool directory defined in the spool_directory directive from the snmptt.ini configuration file. The script then exits.

From here the SNMPTT daemon takes over. It reads the trap from the spool file and searches for a match in its trap definitions. If it finds a match, it executes the EXEC statement in the matching trap definition. This EXEC statement sends the passive check result to the Nagios server using the submit_check_result script. The daemon then sleeps for the period specified in the sleep directive in the snmptt.ini file and checks the spool directory for additional traps; if it finds matches, it processes them and sends the check results to Nagios.

The Nagios server has to have host objects defined for every host that generates SNMP traps. Additionally, you need to define service objects for those hosts to receive the service check results. You should configure them to receive passive check results and as volatile services.

Fixing Oracle SQL Developer on 64 bit Fedora 13

2010-10-29T22:28:00.000-07:00

If getting error while trying to start SQL Developer on 64 bit Fedora

java.lang.UnsatisfiedLinkError: /usr/java/jdk1.6.0_07/jre/lib/i386/xawt/libmawt.so: libXtst.so.6: cannot open shared object file: No such file or directory

The installed libXtst is 64 bit and sqldeveloper will not work until 32bit version of the same package is installed.

Installing 32 bit package on Fedora

sudo yum install packagename.i686

Now to fix the Oracle SQL Developer problem install the 32 bit version of libXtst

sudo yum install libXtst.i686

Cache Only Local DNS Server using dnsmasq

2010-08-30T11:03:00.000-07:00

dnsmasq is the most popular caching DNS choice for small-to-medium deployments is which is both a lightweight DNS server and a lightweight DHCP server. It is a standard package in modern Linux distributions. If your distro doesn't provide it, though, you can download and install the source without too much trouble; there are no major external package dependencies.

Installing dnsmasq on Fedora

# yum install dnsmasq

Configuration

Open the file /etc/dnsmasq.conf as root. There are several dozen configuration options -- all of them well-documented -- but it only takes a few to get set up for normal use. Near the top, uncomment out the listen-address= directive and add the localhost address 127.0.0.1: listen-address=127.0.0.1. This tells dnsmasq to listen for DNS queries that originate on the local machine.

listen-address=127.0.0.1

Edit /etc/resolv.conf, and add nameserver 127.0.0.1 to the top. The locally-running copy of dnsmasq will now receive all DNS queries first, and cache the results.

Starting dnsmasq Service
# /etc/init.d/dnsmasq start

No Video with mplayer on Fedora 13

2010-08-28T12:59:00.000-07:00

After installing Mplayer on Fedora 13 I was facing the problem of no video which was fixed after running the mplayer from command line with the following option

gmplayer -vo xv filename.avi

After running it from command line it start working fine.

Installing Google Command-Line Tool for Linux

2010-06-18T23:02:00.001-07:00

Ever wanted to upload a folder full of photos to Picasa from a command prompt?' Google introduced today a new project, Google CL, that lets you do that and much more. It's a new command line tool for Linux that acts as an interface with Google services; you can upload videos to YouTube or maybe post a new blog post in Blogger in just one line

Installing Google CL:

DEPENDENCIES

GoogleCL requires Python 2.5 or 2.6 and the gdata python client library. You can get the library from the project homepage: http://code.google.com/p/gdata-python-client/

1. Download gdata-2.0.10.tar.gz or .zip
2. extract the source tar zxvf gdata-2.0.10.tar.gz
3. cd gdata-2.0.10
4. Run sudo ./setup.py install

I got this error...

/usr/lib/python2.6/distutils/dist.py:266: UserWarning: Unknown distribution option: 'install_requires'
warnings.warn(msg)
running install
error: invalid Python installation: unable to open /usr/lib/python2.6/config/Makefile (No such file or directory)

In case of above error install python-setuptools-devel which will also install python-devel as dependency,

sudo yum install python-setuptools-devel

and do the step (4) again

Running Tests and Samples

./tests/run_data_tests.py

If this script runs correctly, you should see output on the command line like this:

Running all tests in module gdata_test
.....................
----------------------------------------------------------------------
Ran 21 tests in 0.028s

OK

Running all tests in module atom_test
...............................................
----------------------------------------------------------------------
Ran 47 tests in 0.038s

OK

....

Finally get the Google CL source from http://code.google.com/p/googlecl/

1. Extract the source
tar xvf googlecl-0.9.5.tar.gz

2. change to googlecl-0.9.5 directory and run
sudo python setup.py install

Now you are ready to play with Google CL and starting posting blogs, videos to youtube etc right from your Linux command Line,

One first run for every google service you will get ...

Did not find config / preferences file at /home/myhome/.googlecl/config
... making new one.
Please specify user: myusername
(Hint: You can automatically launch your browser by adding "auth_browser = " to your config file under the GENERAL section, or define the BROWSER environment variable.)
Please log in and/or grant access via your browser at https://www.google.com/accounts/OAuthAuthorizeToken?oauth_token=4%2FglE62XHHpOLmP6jhGGZumt6Tm2re then hit enter.

Specify the username and put the following in the ~/yourhome/.googlecl/config GENERAL section.

auth_browser = firefox

And when browser open Auth Token page click "Grant Acces"

Examples:

1. Post a blog
$ google blogger post --tags "GoogleCL, awesome" --title "Test Post" "I'm posting from the command line"

2. To post a blog from .txt file

$ google blogger post ~/Desktop/googlecl.txt

3. To delete a post
google blogger delete --title "Test Post"
Are you SURE you want to delete post "Test Post"? (y/N): y

For detail examples refer to GooglCL project web

Installing Nagios-plugins and NRPE on Centos 5.x

2010-06-11T23:49:00.000-07:00

To monitor remote hosts CPU load, disk partitions, processes etc with Nagios, requires to install NRPE and nagios-plugins on the remote host.

This is how I do it...

Nagios-plugins and NRPE is not available from Centos official repositories, so first of all we need to configure RPMforge> repo from where to install the required packages.

Read my previous article before configuring and installing anything from third party repo.

Installing RPMforge on Centos 5.x

Download the rpmforge-release package. Choose one of the two links below, selecting to match your host's architecture. If you are unsure of which one to use you can check your architecture with the command uname -i

x386
wget http://packages.sw.be/rpmforge-release/rpmforge-release-0.5.1-1.el5.rf.i386.rpm

x86_64
wget http://packages.sw.be/rpmforge-release/rpmforge-release-0.5.1-1.el5.rf.x86_64.rpm

Install the RPMForget key

rpm --import http://dag.wieers.com/rpm/packages/RPM-GPG-KEY.dag.txt

If key didn't install no worries yum will ask when installing a package from rpmforge repo.

Verify the package you have downloaded
# rpm -K rpmforge-release-0.5.1-1.el5.rf.*.rpm

Install the package
# rpm -ivh rpmforge-release-0.5.1-1.el5.rf.*.rpm

Now everything is setup now you can install nagios-plugins and nrpe packages from RPMforge repo

# yum install nagios-plugins nagios-nrpe

Running NRPE under xinetd

Edit /etc/xinetd.d/nrpe for

disable = no
only_from = 127.0.0.1 NagiosServerIP

Restart xinetd service

# /etc/init.d/xinetd restart

Before using third party repositories on Centos

2010-06-11T23:05:00.000-07:00

Before configuring and installing anything from third party repo, it is recommended to make sure to use Priorities by installing yum-priorities package for your version of Centos

CentOS-4 or CentOS-6:
# yum install yum-plugin-priorities

CentOS-5:
# yum install yum-priorities

After the plugin is installed, make sure that it is enabled when you decide to use a given archive. You can do this by editing the /etc/yum/pluginconf.d/priorities.conf file, and ensuring that it contains the following lines:

[main]
enabled=1
check_obsoletes=1

Set the priorities of Repositories

With the plugin enabled, you may add priorities to repositories by adding the line:

priority=N

where N is an integer from 1 to 99. The default priority for repositories is 99. The repositories with the lowest numerical priority number have the highest priority. Usually, it is best to give at least the CentOS base and update repositories a very high priority.

Give CentOS base,update,addons,extras repositories the highest possible priority (1):

vi /etc/yum.repos.d/CentOS-Base.repo
priority=1

And give centosplus, and contrib priority 2
priority=2

Give low priority = 10 to all the third party repositories by setting repos files in /etc/yum.conf.d directory

For detail refer to the Centos wiki

Upgrading to Fedora 13 with Preupgrade

2010-06-10T10:38:00.000-07:00

Preupgrade is an application users run on a existing release, that resolves and downloads packages required to upgrade to a newer release of Fedora. While Preupgrade downloads the necessary packages, users are free to continue using their systems. This gives an experience similar to a live upgrade. For additional information

While preupgrade provides a generally hassle free upgrade experience. The following steps are recommended before proceeding.

1. Backup - Before performing any system maintenance, it is recommended that you back up all important data before proceeding.
2. Update - Apply available updates Fedora updates before proceeding. As the root user, issue the following command.

# yum update

2. If preupgrade package not already install then install it.

# yum install preupgrade

Perform the upgrade

1. As the root user, run the command preupgrade to start the Preupgrade application. If you prefer a command line application, the command preupgrade-cli is available.

2. On the Choose desired release screen, select the Fedora release (in my case my home laptop running Fedora 12, I have only one option ie Fedora 13) you want to upgrade to , and click the Apply button.

# preupgrade -cli

Checking for new repos for mirrors
* preupgrade-updates: mirror.yandex.ru
Downloading 947.6MB
Available disk space for /var/cache/yum/preupgrade: 2.8GB

relax and do your work while packages being downloaded which will take quit sometime, depending on your Internet connection.

3. When all of the packages have downloaded, reboot your system to start the Fedora installer and upgrade to the next release.

Common post-upgrade tasks.

Refer to the Fedora wiki

Troubleshooting

Not enough space in /boot

Fedora 13 and above has a 500 MB default boot partition. The default /boot filesystem size of 200MB for previous releases can be a problem for users upgrading from that release.

Follow the instructions on Fedora wiki to handle the space problem on /boot partition.

Note: If preupgrade give you message "Not enough space in /boot/upgrade to download install.img." but it can download it after reboot if you have a wired connection to the network, you can click continue for that.

VLC not working after upgrade to Fedora 13.

Fix: If you are getting the invalid pointer error, try running VLC the first time with:

MALLOC_CHECK_=1 vlc

After setting my preferences and quitting, I was then able to run it normally on F13 without issue.

VirtualBox: Networking between Linux Host and Windows XP Guest

2010-06-10T04:31:00.000-07:00

In this article we will learn how to configure networking between Linux host OS and Windows Guest (VM) using Virtualbox

1. First of all download and install Virtualbox on your Linux host and install the guest operating system

2. Now configure network on Guest OS, open VM settings and click Network

3. Select Host-Only Adapter from "Attached to" combo

The VM will create the default network interface named by "vboxnet0" on the host OS,

#ifconfig
vboxnet0 Link encap:Ethernet HWaddr 0A:00:27:00:00:00
          inet addr:192.168.56.1 Bcast:192.168.56.255 Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:3599 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:0 (0.0 b) TX bytes:3896747 (3.7 MiB)

VirtualBox automatically assigned IP address 192.168.56.1 on the host to that network interface.

4. Launch the XP guest OS from virtualbox and configured the network upon VM successfully boot

5. Make sure both Host and guest can responding to each other 'ping'
ping 192.168.56.10
PING 192.168.56.10 (192.168.56.10) 56(84) bytes of data.
64 bytes from 192.168.56.10: icmp_seq=1 ttl=128 time=1.83 ms
64 bytes from 192.168.56.10: icmp_seq=2 ttl=128 time=0.512 ms

Enabling Internet for VM.

Above steps was fine as far as networking between Host and VM is concerned, however if you want to let VM also access the Internet then you have to configure the following iptables rules and enable ipfowarding on Host OS.

# insert NAT rule
iptables -t nat -A POSTROUTING -o vboxnet0 -j MASQUERADE
iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE

# enable forwarding
echo 1 > /proc/sys/net/ipv4/ip_forward

CountDown to 2010 FIFA World Cup South Africa

2010-06-05T03:50:00.000-07:00

I wonders who will miss this amazing event :), I wish I could watch all the matches of this great event.

Italy will be defending its title which they won in the 2006 FWC in Germany against France.

Like all previous Football world cup Brazil will again my favourite team, Brazil is the only team which have qualified for all known FWC and also holding a record of wining FWC 5 times.

Face-Off with Facebook By Irfan Husain (The Dawn)

2010-05-26T04:04:00.000-07:00

Recently Pakistan Government went on blocking Facebook (social networking) the site carrying the blasphemous drawings of the Holy Prophet [PBUH].

Read the full article here.

Fedora 13 Is Out

2010-05-26T03:48:00.000-07:00

Thanks to Fedora folks for releasing yet another release of one of the best Linux distro.

Fedora 13 includes some major features like automatic print driver installation, automatic language pack installation, redesigned user account tool, color management to calibrate monitors and scanners, experimental 3D support for NVIDIA video cards, and more in the release notes.

Currently I have Fedora 12 installed which will be supported for quit sometime (almost six months) so there is no need to rush for new release yet.

Whenever I need to upgrade I'll decide to use one of the following tool/option for upgrading my home and work laptops.

Preupgrade
Using boot images available from http://boot.fedoraproject.org/

Though last time upgrading from Fedora 11 'preupgrade' work like a charm for me, so there is a chance that this time I'll also go with preupgrade.

Vnstat a console based network traffic monitor

2010-03-19T03:09:00.000-07:00

vnStat is a console-based network traffic monitor for Linux and BSD that keeps a log of network traffic for the selected interface(s). It uses the network interface statistics provided by the kernel as information source. This means that vnStat won't actually be sniffing any traffic and also ensures light use of system resources.

The beautiy of Vnstat is that its very simple to install and configure

Installing vnstat on Fedora

Thanks to Fedora folks vnstat can now be installed from Fedora repository using 'yum', please refer to your distro package management commands for installing vnstat on other distros.

yum install vnstat

Monitoring Interface traffic

The commmand forces a database update for interface or creates the database if it doesn’t exist. This is usually the first command used after a fresh install.

vnstat -u -i Interface

Replace with the Interface name eg, eth0, wlan0 etc

Displaying statistics:

After installation and creating a interface database vnstat can be used from command line to display network traffic statistics

$ vnstat --help

vnStat 1.6 by Teemu Toivola

         -q, --query          query database
         -h, --hours          show hours
         -d, --days           show days
         -m, --months         show months
         -w, --weeks          show weeks
         -t, --top10          show top10
         -s, --short          use short output
         -u, --update         update database
         -i, --iface          select interface (default: eth0)
         -?, --help           short help
         -v, --version        show version
         -tr, --traffic        calculate traffic
         -l, --live           show transfer rate in real time

Sending SMS Notifications From Nagios

2010-03-02T03:09:00.000-08:00

In my last article I have discuses how to install Gnokii for sending/receiving SMS from your computer. Today I'll explain how we are using Gnokii + Nagios for sending SMS notifications to our cell phones. Its a great way to get notify of the problems while on road.

I assume that you have working Nagios and its monitoring the devices in your infrastructure and sending notifications via Email and you are looking how to get these problem notifications on your phones.

Gnokii is also working and you can send SMS from CLI.

Lets cut it short and back to actual business.

In my setup we have Nagios and Gnokii install on same host running Centos 5.4, but it can easily be followed for any other Linux distro or even with setup where Gnokii is install on separate host.

1. Make sure you can send SMS from CLI with "gnokii --sendsms +92xxxxx" using root or the user under which Nagios process is running normally its 'nagios' user, sending under nagios user requires to add nagios to groups which have permission to access the device files.

a) So add nagios to 'uucp' group (you can do this with usermod command)

Gnokii also acquire a lock under /var/lock

b) So add nagios user to 'lock' group also.

su to nagios user and send sms from CLI using gnokii --sendsms, when it works move forward for defining commands.

2. Define command for send notification via SMS in commands.cfg

# 'notify-service-by-sms' command definition
define command{
command_name notify-service-by-sms
command_line /usr/bin/printf "%.120s" "*** Nagios Alert*** $HOSTALIAS$/$SERVICEDESC$ is $SERVICESTATE$" | /usr/local/bin/gnokii --sendsms $CONTACTPAGER$
}

# 'notify-host-by-sms' command definition
define command{
command_name notify-host-by-sms
command_line /usr/bin/printf "%.120s" "*** Nagios Alert*** $NOTIFICATIONTYPE$ : Host $HOSTALIAS$ is $HOSTSTATE$" | /usr/local/bin/gnokii --sendsms $CONTACTPAGER$
}

3. Modify contacts.cfg and add or modify a contact by calling new commands

define contact{
contact_name askarali
use generic-contact
alias Askar Ali Khan
email emailaddress
pager +92xxxxxx
service_notification_commands notify-service-by-email,notify-service-by-sms
host_notification_commands notify-host-by-email,notify-host-by-sms
}

The key in the contact detail is the service/host notifications commands

service_notification_commands notify-service-by-email,notify-service-by-sms
host_notification_commands notify-host-by-email,notify-host-by-sms

I have configured a contact so that he can receive notifications via Email 'notify-service-by-email' as well as via SMS 'notify-service-by-sms'

That's all, finally reload nagios, before reload better to run syntax check

'nagios -v PathTo nagios.cfg'

and then reload

/etc/init.d/nagios reload

Now Nagios will send SMS notifications on your phone whenever there is problem with any host/service which being monitor with Nagios.

I hope this could help.

Bash Scripting - Adding pipe "|" to each line of text file

2010-03-02T02:08:00.000-08:00

Here is a simple script which will add a pipe symbol '|' to the start and end of every line in a text file.

Well do not ask why I need to do this, it was needed for some nasty text files which we have to deal with in our day to day works.

Someone will argue why the hell we need a script for this simple task when we can do the same with 'vi', well I must say chill mate...yes there are more then one way to do the work done, and using the script way you don't have to open a file or what if you have to work with more then one txt file? its easy to run a script "add_pipe" and sit back instead of vi file1;vi file2. :)

Script can be easily modified to accept the "SOURCEDIR" from command line or adding any other symbol, currently I put all such text files in /tmp/manual before running the script.

The Script:

#!/bin/sh
# Purpose: To add pipe '|' to begin and end of line in a txt file.
# Date: 2010-02-25
# add_pipes

# Directory to where files need to process for adding pipe
SOURCEDIR="/tmp/manual"

# Change to source directory
if [ -d "$SOURCEDIR" ];then
cd "$SOURCEDIR"
else
exit 1
fi

# First convert the files to Unix (if imported from M$ files carries the carrige return
CR='\015' # Carriage return.
           # 015 is octal ASCII code for CR.
           # Lines in a DOS text file end in CR-LF.
           # Lines in a UNIX text file end in LF only.

for file in $(ls)
do
if [ ! -d "$file" ];then
tr -d $CR < $file >newname
mv newname $file
fi
done

# Finally add pipe by loop through files
for file in $(ls)
do
if [ ! -d "$file" ];then
#sed -e 's/^/|/g' -e 's/\r$/|/g' < $file >newname
sed -e 's/^/|/g' -e 's/$/|/g' < $file >newname
mv newname $file
fi
done
# End

Installing and configuring caching nameserver (named) on Linux (Fedora 12)

2010-02-19T01:06:00.000-08:00

To configure caching-nameserver on local machine in my case on my laptop running Fedora 12, local caching nameserver which will use "cascade" to other functional DNS server in this case my ISP DNS servers.

Advantage: Reduces the delay in domain name resolution drastically as the requests for frequently accessed websites are served from cache. Google for cache nameserver to learn more.

Installing caching-nameserver:

# yum install caching-nameserver

Configuring caching-nameserver:

The main configuration file reside in /etc/named.conf

Not much need to be changed in this file, however if you want to cascade your ISP DNS servers as forwarder, then edit the named.conf and add forwarder directive under the 'options' section.

options {
        listen-on port 53 { 127.0.0.1; };
        listen-on-v6 port 53 { ::1; };
        directory       "/var/named";
        dump-file       "/var/named/data/cache_dump.db";
        statistics-file "/var/named/data/named_stats.txt";
        memstatistics-file "/var/named/data/named_mem_stats.txt";
        allow-query     { localhost; };
        recursion yes;
    // Replace the IPs with the DNS of your ISP
    forwarders { 192.168.36.204; 192.168.36.210; };
        dnssec-enable yes;
        dnssec-validation yes;
        dnssec-lookaside . trust-anchor dlv.isc.org.;
};

And if you do not want to use 'dnssec' then disable it by...

dnssec-enable no;
dnssec-validation no;

Starting caching-nameserver:

# service named start

Or

# /etc/init.d/named start

To make named start every time you reboot your machine

# chkconfig named on

Or

# setup

Go to "System services" and check named

Using caching-nameserver:

To use your caching-nameserver, add the following line to /etc/resolv.conf

nameserver 127.0.0.1

Now your system will use your own nameserver (in caching mode) for resolving all domain names

$ dig askarali.org
Query time: 8 msec

First time the response time will be little high, next time the DNS query response will be served from local cache and will takes very little time

$ dig askarali.org
$ Query time: 0 msec

Sending SNMP Traps from Nagios

2010-02-12T21:52:00.000-08:00

As well as receiving SNMP traps in Nagios, you can send SNMP traps from Nagios to a remote SNMP management station like HP OpenView (NNM) or the like. The easiest way to do this is to create a notification command that generates an SNMP trap. This way, you can use an SNMP management station as a notification destination. This will mean that the trap will be sent every time a notification is scheduled.

Prerequisites:

net-snmp, net-snmp-utils should be installed on Monitoring host running Nagios

Connectivity between management station and nagios has been stablished and nagios can connect and send snmptraps to snmptrap 162/udp port on management station.

1. First of all define notification command, below is the commands for service and hosts in commands.cfg

# 'send-service-trap' command definition
define command{
      command_name send-service-trap
      command_line /usr/local/bin/send-service-trap manager public "$HOSTNAME$" "$SERVICEDESC$" $SERVICESTATEID$ "$SERVICEOUTPUT$"
}

# 'send-host-trap' command definition
define command{
                command_name send-host-trap
                command_line /usr/local/bin/send-host-trap manager public "$HOSTNAME$" $HOSTSTATEID$ "$HOSTOUTPUT$"
}

Both the commands call the shell scripts send-service-trap and send-host-trap in /usr/local/bin/. Passing the hostname or IP address of the destination management station and the target community string, manager and public, respectively.

A number of macros are also passed to the shell script representing the hostname, the service description, the service/host state in numeric form, and the output of the host/service check.

The snmptrap tool generates SNMP traps and can send them to remote management stations. The traps are generated according to a Nagios
MIB available from the same Sourceforge project as the Nagios plug-ins. You can download the MIB from http://prdownloads.sourceforge.net/nagiosplug/nagiosmib-1.0.0.tar.gz?download.

The package contains two MIB files: a root MIB file containing basic definitions for Nagios OIDs called NAGIOS-ROOT-MIB and an MIB containing events and traps called NAGIOS-NOTIFY-MIB. You will need to install both MIB files into your SNMP management device; for example, if your trap daemon is the snmptrapd daemon, you would generally copy these files to the /usr/share/snmp/mibs directory. When you start the snmptrapd daemon, you load the MIB files using the -m
and -M options:

Also copy the MIBs files on localhost where Nagios is running under snmp/mibs

/usr/sbin/snmptrapd -m ALL -M /usr/share/snmp/mibs -Lf /var/log/snmptrapd.log

Tip: There is an excellent HOWTO on how to use snmptrap to send traps here.

Note: Your own SNMP management station, such as HP OpenView or the like, will have its own method of loading MIB files. You should refer to its documentation for that.

2. Define a contact for Management station

Need to define a contact for management station in the same way we create for other contact person, to receive SNMP traps from Nagios whereever Nagios send notificaiton for host/service

define contact{
        contact_name                             managementstation
        use                                              generic-contact
        alias                                            Management Station
        service_notification_options    w,u,c,r
        host_notification_options         d,u,r
        service_notification_commands   send-service-trap
        host_notification_commands      send-host-trap
        }

3. Add the new conatct to contactgroup for hosts/services for which you want to send SNMP traps

define contactgroup{
        contactgroup_name       linuxadmins
        alias                                Linux Servers Administrators
        members                         me, managementstation
}

Now whenever there is a alert for linux servers Nagios will notify contact "managementstation" which in turn call the commands send-service-trap/send-host-trap accordingly depends on host or service alert.

4. send-service-trap/send-host-trap Shell Script

===/usr/local/bin/send-service-trap ====
# Arguments:
# $1 = Management Station
# $2 = Community String
# $3 = host_name
# $4 = service_description (Description of the service)
# $5 = return_code (An integer that determines the state
#       of the service check, 0=OK, 1=WARNING, 2=CRITICAL,
#       3=UNKNOWN).
# $6 = plugin_output (A text string that should be used
#       as the plugin output for the service check)
#
#
/usr/bin/snmptrap -v 2c -c $2 $1 '' NAGIOS-NOTIFY-MIB::nSvcEvent nSvcHostname s "$3" nSvcDesc s "$4" nSvcStateID i $5 nSvcOutput s "$6"

===/usr/local/bin/send-host-trap=======
# Arguments:
# $1 = Management Station
# $2 = Community String
# $3 = host_name
# $4 = HostStatID A number that corresponds to the current state of the host: 0=UP, 1=DOWN, 2=UNREACHABLE.
# $5 = HOSTOUTPUT The first line of text output from the last host check (i.e. "Ping OK").
#
#
/usr/bin/snmptrap -v 2c -c $2 $1 '' NAGIOS-NOTIFY-MIB::nHostEvent nHostname s "$3" nHostStateID i $4 nHostOutput s "$5"

The shell script receives all the incoming variables and passes them to the snmptrap command

-v = snmp version
-c = community string
$1 = Management Station IP address or hostname

The next two single quotes are special characters representing the uptime portion of a trap. They will be replaced with the current uptime of the system generating the trap when the snmptrap command is executed.

The enterprise OID is specified next; in this case it is NAGIOS-NOTIFY-MIB::nSvcEvent and NAGIOS-NOTIFY-MIB::nHostEvent. The NAGIOS-NOTIFY-MIB is the name of the MIB module being referenced, and the nSvcEvent/nHostEvent is the trap defined for sending service events. Together these form the enterprise OID.

Next specified a list of individual OIDs and their variables that I’m passing as part of the trap. They are, in order, the hostname, the service description, the host/service status ID in numerical form, and the output of the host/service check.

Enclosing the values ones that might contain multiword data in quotation marks so that they are passed cleanly to the command.

Tip: You can find these and other OIDs that you can use with the traps and notifications defined in the NAGIOS-ROOT-MIB and NAGIOS-NOTIFY-MIB MIB files.

Creating Custom Template in pnp4nagios

2010-01-15T01:05:00.000-08:00

Some time need to create custom template in pnp4nagios for some command which behave differently when execute on remote host as the appearance of graphs depends on the check command used. eg check_nrpe

Example:

define command {
command_name check_nrpe
command_line $USER1$/check_nrpe -H $HOSTADDRESS$ -c $ARG1$
}

This would lead to a call of the check_nrpe.php template even when the monitored host would use a completely different plugin which is called via NRPE, eg

In service definition

define service{
use local-service,srv-pnp
host_name SomeHost
service_description Current Load
check_command check_nrpe!check_load
}

This will lead to call to check_nrpe command and it will use the default.php PNP template which may or may not give the graph as required.

Solution: Custom Template

1. Define new command in nagios/commands.cfg

define command{
command_name check_nrpe_load
command_line $USER1$/check_nrpe -H $HOSTADDRESS$ -c $ARG1$
}

2. Modify the service command for the host to use the new command

define service{
use local-service,srv-pnp
host_name SomeHost
service_description Current Load
check_command check_nrpe_load!check_load
}

Reload Nagios so that it start using the new check command.

At this point everything will be working just as before,

Pnp4nagios configuration

1. Define a check command /usr/local/pnp4nagios/etc/check_commands/check_nrpe_load.cfg (with the same name as the check command in above example)

Tip: Just copy the sample command definition /usr/local/pnp4nagios/etc/check_commands/check_nwstat.cfg-sample eg

cd /usr/local/pnp4nagios/etc/check_commands
sudo cp check_nwstat.cfg-sample check_nrpe_load.cfg

For more detail on custom command refer to http://docs.pnp4nagios.org/pnp-0.6/tpl_custom

2. Define a customer template for check_nrpe_load

In the above example if check_nrpe_load.cfg have

CUSTOM_TEMPLATE = 0,1 the it will results in → "check_nrpe_load_check_load.php"

Create a custom template in /usr/local/pnp4nagios/share/templates (pnp4nagios first look for template in this direcotry then fallback to other directories http://docs.pnp4nagios.org/pnp-0.6/tpl)

Note: Or you can just create a symbolic link to existing template that come with pnp4nagios installation eg ...

ln -s ../templates.dist/check_load.php check_nrpe_load_check_load.php

Here is the sample template for check_load on remote hosts that will plot graph of 1M and 15 minute graph for a host,

cd /usr/local/pnp4nagios/share/templates

sudo vi check_nrpe_load_check_load.php (template name should match with the custom command definition in our example check_nrpe_load_check_load.php)

<?php
$opt[1] = "--vertical-label Load -l0 -u 1 --title \"CPU Load for $hostname / $servicedesc\" ";

$def[1] = "DEF:var1=$rrdfile:$DS[1]:AVERAGE " ;
$def[1] .= "DEF:var2=$rrdfile:$DS[2]:AVERAGE " ;
$def[1] .= "DEF:var3=$rrdfile:$DS[3]:AVERAGE " ;
if ($WARN[1] != "") {
$def[1] .= "HRULE:$WARN[1]#FFFF00 ";
}
if ($CRIT[1] != "") {
$def[1] .= "HRULE:$CRIT[1]#FF0000 ";
}
$def[1] .= "AREA:var1#EACC00:\"Load average 1 min \" " ;
$def[1] .= "GPRINT:var1:LAST:\"%6.2lf last\" " ;
$def[1] .= "GPRINT:var1:AVERAGE:\"%6.2lf avg\" " ;
$def[1] .= "GPRINT:var1:MAX:\"%6.2lf max\\n\" ";
$def[1] .= "LINE:var3#FF0000:\"Load average 15 min \" " ;
$def[1] .= "GPRINT:var3:LAST:\"%6.2lf last\" " ;
$def[1] .= "GPRINT:var3:AVERAGE:\"%6.2lf avg\" " ;
$def[1] .= "GPRINT:var3:MAX:\"%6.2lf max\\n\" " ;
?>

Nagios addon - pnp4nagios

2010-01-10T21:04:00.000-08:00

PNP4Nagios is a gem of an add-on; it allows a Nagios administrator to easily add RRD-style graphs and efficient long-term trending capabilities to Nagios. This graphing framework makes extensive use of templates and is easy to customize. It consists of a PHP-based front using Kohana framework.

Pnp4nagios uses kohana framework for web frontend and kohana requires php 5.2.x has to be installed. In my previous post I have describe how to upgrade to php 5.2.x on centos which comes with 5.1.x.

System Requirement

Perl >= 5.x
RRDtool
PHP >= 5.2. for the Webfrontend based on Kohana
PHP-extension zlib, session and GD.
Nagios >= 2.x

Installation

Joerg Linge have written excellent documentation for pnp4nagios and using it one can easily install and configure PNP in no time.

In my case I have used the following ./configure line to have rrd data under nagios directories and rest of pnp4nagios goes its own directories in filesystem.

./configure --with-perfdata-logfile=/var/nagios/perfdata.log --with-perfdata-dir=/var/nagios/perfdata --with-perfdata-spool-dir=/var/nagios/spool/perfdata

After installing follow the pnp docs for start generating graphs and web integration with Nagios.

Before going for production use, decide which mode is right for your Nagios installation.

In our case we go with Bulk Mode with NPCD as per docs...

Nagios again uses a temporary file to store the data and executes a command after expiration of a certain time. Instead of immediate processing by process_perfdata.pl the file is moved to a spool directory. As moving a file inside the same filesystem nearly takes no time nagios is able to execute crucial work immediately.
The NPCD daemon (Nagios Performance C Daemon) will monitor the directory for new files and will pass the names to process_perfdata.pl. Processing of performance data is decoupled completely from nagios. NPCD itself is able to start multiple thread for processing the data.

Pages

One of the cool feature of pnp4nagios to have separate pages of graphs for hosts/services on a single page.
Once again Joerg have an excellent docs for configuring pages.

Conclusion

Once installed and configured pnp4nagios provides trending and capacity planning which allows organizations to plan for infrastructure upgrades before outdated systems catch them by surprise.

Picasa 3 sucks

2010-01-10T02:38:00.000-08:00

Today after upgrading to Picasa 3 on Fedora 12, it no longer let me upload my photos to web album, each time it gives the same error

Login failed - please try again later.

I have exhausted all the options googling, uninstall and reinstall but no luck.

Come on Google you should be watching your groups on which people crying for the issue of sign in after installing/upgrading to picasa 3.

Adding chunk to dbspace in IBM Informix (IDS) using 'onspaces' utility

2010-01-03T23:17:00.000-08:00

Recently I got into problem when there was on space left on dbspace on one of our Informix database. It took me nearly 2 hours of Googling to figure out how to add CHUNK to existing dbspace.

I thinks it would be better to blog it, this might help some other folks or might I need to use it some day when the newly added CHUNK also get full :)

For my setup I do not have the additional hard drive and have a plenty of free space on Unix partition. Therefore I used the unix file as new Chunk.

'onmonitor', oncheck -pe, onstat -d commands can be used to view the status of dbspaces.

Here are the steps to add chunk.

1. First create a chunk file in Unix filesystem and set the permission so that informix user/group have the read/write permission on the file.

touch /export/home/dbspace/billdb_dg/lv_recorddbs11

chmod 660 /export/home/dbspace/billdb_dg/lv_recorddbs11

Note: I run the above commands with 'informix' user or the owner of informix db.

The following example adds a 2GB chunk to recordbs. An offset of 200 kilobytes is specified.

onspaces -a recorddbs -p /export/home/dbspace/billdb_dg/lv_recorddbs11 -o 200 -s 2093150

Here -s 2093150 is specified in KB

The newly added chunk is available immediately.

After you create the chunk, you must perform a level-0 backup of the root dbspace and the dbspace that contains the chunk.

Chat with Joerg Linge developer/maintainer of pnp4nagios

2010-01-01T09:34:00.000-08:00

Today I got an opportunity to chat with developer/maintainer Joerg Linge of pnp4nagios.

Chat was mostly about the new feature of using multiple Data Sources for a service in pnp4nagos.

RRD_STORAE_TYPE = SINGLE means: Store every Datasource in one single RRD Database i.e. for check_icmp this is DS 'pl' and DS 'rta'

With RRD_STORAE_TYPE = MULTILPLE every DS is stored in its own RRD Database i.e. host/service_pl.rrd and host/service_rta.rrd

RRD_STORAE_TYPE = MULTILPLE should only used when a plugin is able to change the number of DS like check_disk does.

Me: Is it ok to set RRD_STORAE_TYPE = MULTIPLE globally in process_perfdata.cfg for new installation of Joerg? when one do not have any RRD data at all.
Me: tomorrow i am going to deploy Joerg 0.6.x on our production nagios server.
Me: thanks.
Joerg : it depends
Joerg : happy new year!
Me: happy new year :)
Me: ok,
Me: going with MULTIPLE has no drawback ok?
Joerg : multiple mean more Disk I/O because of more RRDs to update

Joerg : on sytems with 10000+ rrds you have to look on your disk I/O clisely
Me: well this really need very close monitoring of I/O which is hard to follow :s
Me: better stick with SINGLE :)
Joerg : right
Joerg : there are some plugins with changing DS counts like check_disk
Joerg : in this case multiple is an option
Joerg : or check_oracle_health for tablespace monitoring
Me: we are using check_disk extensively.
Me: for checking servers partitions.
Joerg : one check for all filesystems?
Me: well mostly separate check_disk for each fs, however we have some servers with lot of fs onthese servers we are using single check_disk to check multiple fs in one go.
Me: with -p option
Me: those are mostly HP-UX
Joerg : so check_disk can be used with multiple
Me: ok to use multiple have to configure it globally?
Joerg : wenn you add a nw filesystem, rrdtool is not able to update the rrd databases
Joerg : lol german wenn
Joerg : english when
Joerg : sorry
Me: np, i thought its typo :)
Me: ok to use multiple have to configure it globally? or their is another way around?
Joerg : moment
Joerg : http://docs.Joerg.org/pnp-0.6/tpl_custom
Me: looking.
Joerg : you can set RRD_STORAGE_TYPE per check_commands
Joerg : i.e. your command is check_disk
Joerg : create etc/check_commands/check_disk.cfg
Joerg : set RRD_STORAGE_TYPE = MULTIPLE within this file
Joerg : thats the same rrd_convert.pl --check_command=check_disk will do in its final version
Me: ok but for most host we are doing the check_disk on remote host and then using check_nrpe on nagios host
Joerg : so your command is?
Joerg : check_nrpe?
Me: yes
Joerg : create a new command nrpe_disk
Joerg : thats it
Me: can you give me full example of nrpe_disk here?
Joerg : define command {
Joerg : command_name nrpe_disk
Joerg : command line $USER1$/check_nrpe -H $HOSTqADDRESS$ -c check_diks1
Joerg : }
Joerg : so your command is nrpe_disk and not check_nrpe
Joerg : and now you are able to define MULTIPLE for this command
Joerg : this is done by creating Joerg/etc/check_commands/nrpe_disk.cfg
Me: Thanks for your time very much appreciated.

Installing PHP 5.2.x on Centos

2009-12-28T23:55:00.000-08:00

Recently I have got into issue where the PHP framework requires php 5.2.x while the installed system of centos 5.4 have php 5.1.x.

The Testing repo of centos have php 5.2.x, I followed the following steps to install the php 5.2.x from centos dev repository.

Method 1: Which will install all the new packages from Centos Testing repo.

sudo vi /etc/yum.repos.d/Centos-Test.repo

[c5-testing]
name=CentOS-5 Testing
baseurl=http://dev.centos.org/centos/$releasever/testing/$basearch/
enabled=0
gpgcheck=1
priority=1
gpgkey=http://dev.centos.org/centos/RPM-GPG-KEY-CentOS-testing

# CentOS-Testing:
# !!!! CAUTION !!!!
# This repository is a proving grounds for packages on their way to CentOSPlus and CentOS Extras.
# They may or may not replace core CentOS packages, and are not guaranteed to function properly.
# These packages build and install, but are waiting for feedback from testers as to
# functionality and stability. Packages in this repository will come and go during the
# development period, so it should not be left enabled or used on production systems without due
# consideration.

If you are using "yum-priorities" like me then you also have to add the following to the above

priority=1

Now install the updates

sudo yum --enablerepo=c5-testing update <--- this will install php 5.2.x along with other latest packages from Centos dev repo.

I am not sure how safe its to enable testing repository on production server in my case its a testing server so I can play with it.

Method 2: Only install php 5.2.x and related packages from Centos Testing Repo

sudo yum --enablerepo=c5-testing update php-*

=============================================================================================================================================================
Package                               Arch                          Version                                       Repository                           Size
=============================================================================================================================================================
Updating:
php                                   i386                          5.2.9-2.el5.centos                            c5-testing                          1.2 M
php-cli                               i386                          5.2.9-2.el5.centos                            c5-testing                          2.4 M
php-common                            i386                          5.2.9-2.el5.centos                            c5-testing                          237 k
php-mbstring                          i386                          5.2.9-2.el5.centos                            c5-testing                          1.1 M
php-mysql                             i386                          5.2.9-2.el5.centos                            c5-testing                           80 k
php-pdo                               i386                          5.2.9-2.el5.centos                            c5-testing                           62 k

Transaction Summary
=============================================================================================================================================================

This will install the php packages

For more information click Centos Repositories.

Fedora 12 Yum New Feature 'history'

2009-12-19T23:56:00.000-08:00

With Fedora 12 which was recently released and with F12 new version of Yum package manager also released. One of the new feature that new version of Yum bring is history.

The history command allows the user to view what has happened in past transactions. You can use info/list/summary to view what happened, undo/redo to act on that information and new to start a new his-tory file.

The info/list/summary commands take either a transactions id or a package (with wildcards, as in Specifying package names), all three can also be passed no arguments. list can be passed the keyword "all" to list all the transactions. undo/redo just take a transaction id.

Here are few examples:

$ sudo yum history
Loaded plugins: dellsysidplugin2, fastestmirror, refresh-packagekit
ID     | Login user             | Date and time    | Action(s)      | Altered
-------------------------------------------------------------------------------
    23 | Askar Ali Khan | 2009-12-19 20:29 | Update         |   35
    22 | Askar Ali Khan | 2009-12-19 20:22 | Install        |    1
    21 | Askar Ali Khan | 2009-12-19 19:57 | Erase          |    1
    20 | System          | 2009-12-16 20:16 | Update         |   20
    19 | System          | 2009-12-13 10:03 | E, I, U        |   51
    18 | System          | 2009-12-09 19:19 | Install        |    1
    17 | System          | 2009-12-09 19:12 | Update         |   14
    16 | System          | 2009-12-07 20:51 | I, U           |   33
    15 | System          | 2009-12-03 17:20 | Update         |   10
    14 | Askar Ali Khan | 2009-12-02 17:57 | I, O, U        |   56
    13 | System          | 2009-11-30 20:37 | Update         |   46
    12 | Askar Ali Khan | 2009-11-30 20:29 | Install        |    1
    11 | Askar Ali Khan | 2009-11-25 20:53 | Update         |   19 <
    10 | Askar Ali Khan | 2009-11-22 09:55 | Erase          |    1 >
     9 | Askar Ali Khan | 2009-11-22 09:55 | Erase          |    3
     8 | Askar Ali Khan | 2009-11-22 09:54 | Install        |    1
     7 | Askar Ali Khan | 2009-11-22 09:53 | Install        |    1
     6 | Askar Ali Khan | 2009-11-22 09:52 | Erase          |    1
     5 | Askar Ali Khan | 2009-11-22 09:50 | Erase          |    3
     4 | System          | 2009-11-20 19:12 | I, U           |   38

To list packages of a transaction, use option 'info' followed by transactions id

$sudo yum history info 15
Loaded plugins: dellsysidplugin2, fastestmirror, refresh-packagekit
Transaction ID : 15
Begin time     : Thu Dec 3 17:20:15 2009
Begin rpmdb    : 1328:10c8f90e66eb2c26aa380265fb4b5b11e56aae7a
End time       :            17:20:53 2009 (38 seconds)
End rpmdb      : 1328:465b91d25241fa9452547719e554f9fb8ec9ac73
User           : System
Return-Code    : Success
Transaction performed with:
    Installed    rpm-4.7.1-6.fc12.i686
    Installed    yum-3.2.25-1.fc12.noarch
    Installed    yum-metadata-parser-1.1.2-14.fc12.i686
    Installed    yum-plugin-fastestmirror-1.1.24-2.fc12.noarch
Packages Altered:
    Updated      fontpackages-filesystem-1.35-1.fc12.noarch
    Update                               1.41-1.fc12.noarch
    Updated      gnome-python2-applet-2.28.0-1.fc12.i686
    Update                            2.28.0-2.fc12.i686
    Updated      gnome-python2-desktop-2.28.0-1.fc12.i686
    Update                             2.28.0-2.fc12.i686
    Updated      gnome-python2-gnomekeyring-2.28.0-1.fc12.i686
    Update                                  2.28.0-2.fc12.i686
    Updated      gnome-python2-libwnck-2.28.0-1.fc12.i686
    Update                             2.28.0-2.fc12.i686
    Updated      libsndfile-1.0.20-2.fc12.i686
    Update                  1.0.20-3.fc12.i686
    Updated      liveusb-creator-3.8.6-1.fc12.noarch
    Update                       3.8.7-1.fc12.noarch
    Updated      mdadm-3.0.3-1.fc12.i686
    Update             3.0.3-2.fc12.i686
    Updated      wget-1.11.4-5.fc12.i686
    Update            1.12-2.fc12.i686
    Updated      xorg-x11-drv-dummy-0.3.2-3.fc12.i686
    Update                          0.3.3-1.fc12.i686
history info

Now to undo a transaction, use option 'undo' with the transaction id:

$ sudo yum history undo 22
Loaded plugins: dellsysidplugin2, fastestmirror, refresh-packagekit
Loading mirror speeds from cached hostfile
updates/metalink                                                                                                                      | 7.7 kB     00:00
* fedora: mirrors.cytanet.com.cy
Undoing transaction 22, from Sat Dec 19 20:22:12 2009
    Install      gnokii-0.6.28-1.fc12.i686
Resolving Dependencies
--> Running transaction check
---> Package gnokii.i686 0:0.6.28-1.fc12 set to be erased
--> Finished Dependency Resolution

Dependencies Resolved

=============================================================================================================================================================
Package                            Arch                             Version                                     Repository                             Size
=============================================================================================================================================================
Removing:
gnokii                             i686                             0.6.28-1.fc12                               installed                             1.9 M

Transaction Summary
=============================================================================================================================================================
Remove        1 Package(s)
Reinstall     0 Package(s)
Downgrade     0 Package(s)

Is this ok [y/N]: y
Downloading Packages:
Running rpm_check_debug
Running Transaction Test
Finished Transaction Test
Transaction Test Succeeded
Running Transaction
Erasing        : gnokii-0.6.28-1.fc12.i686                                                                                                             1/1
warning: /etc/gnokiirc saved as /etc/gnokiirc.rpmsave

Removed:
gnokii.i686 0:0.6.28-1.fc12

Complete!

Undoing transaction 22 creates a transaction 24. If you want to reinstall what was installed in transaction 22, do the following:

$ sudo yum history redo 22
Loaded plugins: dellsysidplugin2, fastestmirror, refresh-packagekit
Loading mirror speeds from cached hostfile
* fedora: mirrors.cytanet.com.cy
* rpmfusion-free: ftp-stud.hs-esslingen.de
* rpmfusion-free-updates: ftp-stud.hs-esslingen.de
* rpmfusion-nonfree: ftp-stud.hs-esslingen.de
* rpmfusion-nonfree-updates: ftp-stud.hs-esslingen.de
* updates: mirrors.cytanet.com.cy
Repeating transaction 22, from Sat Dec 19 20:22:12 2009
    Install      gnokii-0.6.28-1.fc12.i686
Resolving Dependencies
--> Running transaction check
---> Package gnokii.i686 0:0.6.28-1.fc12 set to be updated
--> Finished Dependency Resolution

Dependencies Resolved

=============================================================================================================================================================
Package                             Arch                              Version                                     Repository                           Size
=============================================================================================================================================================
Installing:
gnokii                              i686                              0.6.28-1.fc12                               fedora                              539 k

Transaction Summary
=============================================================================================================================================================
Install       1 Package(s)
Upgrade       0 Package(s)

Total download size: 539 k
Is this ok [y/N]: y
Downloading Packages:
gnokii-0.6.28-1.fc12.i686.rpm                                                                                                         | 539 kB     00:03
Running rpm_check_debug
Running Transaction Test
Finished Transaction Test
Transaction Test Succeeded
Running Transaction
Installing     : gnokii-0.6.28-1.fc12.i686                                                                                                             1/1

Installed:
gnokii.i686 0:0.6.28-1.fc12

Complete!

Option 'summary' associated with a package name gives the list of transaction where that package is involved.

$ sudo yum history summary gnokii
Loaded plugins: dellsysidplugin2, fastestmirror, refresh-packagekit
Login user                 | Time                | Action(s)        | Altered
-------------------------------------------------------------------------------
Askar Ali Khan      | Last day            | E, I             |        4
System              | Last 3 months       | I, O, U          |     3909
history summary

And finally here is the option 'list'

$ sudo yum history list gnokii
Loaded plugins: dellsysidplugin2, fastestmirror, refresh-packagekit
ID     | Login user             | Date and time    | Action(s)      | Altered
-------------------------------------------------------------------------------
    25 | Askar Ali Khan | 2009-12-20 12:50 | Install        |    1
    24 | Askar Ali Khan | 2009-12-20 12:46 | Erase          |    1
    22 | Askar Ali Khan | 2009-12-19 20:22 | Install        |    1
    21 | Askar Ali Khan | 2009-12-19 19:57 | Erase          |    1
     3 | System          | 2009-11-20 01:11 | I, O, U        | 1303
     2 | System          | 2009-11-20 00:21 | I, O, U        | 1303
     1 | System          | 2009-11-19 05:40 | I, O, U        | 1303
history list

Nagios and SNMP Traps

2009-12-16T07:17:00.000-08:00

Recently I have worked on sending and receiving SNMP Traps to and from Nagios, its was really a great experience to extend Nagios alerts to other Managers for example HP NNM. Soon I'll document all the process.

Google Launches Public DNS Resolver

2009-12-14T01:32:00.000-08:00

Recently Google launches their free DNS resolution service, called Google Public DNS.
According to their blog post, Google Public DNS uses continuous record prefetching to avoid cache misses — hopefully making the service faster — and implements a variety of techniques to block spoofing attempts. They also say that (unlike an increasing number of ISPs), Google Public DNS behaves exactly according to the DNS standard, and will not redirect you to advertising in the event of a failed lookup.

Google DNS Server IP Addresses

The Google Public DNS IP addresses are as follows:

8.8.8.8

8.8.4.4

Add Google DNS Server IP Address Under Linux

Edit the /etc/resolv.conf file and add above two ip address:

nameserver 8.8.8.8
nameserver 8.8.4.4

Mount an ISO image under Linux

2009-12-14T01:10:00.000-08:00

Mounting ISO images under Linux using loop device.

Assuming /mnt/disk directory is already exists, if not then create it before running the below command.

Mount:

# mount -o loop PathTo/images.iso /mnt/disk

That's it, images.iso has been mounted under /mnt/disk and now you can browse the files.

Unmount:

# umount /mnt/disk

What is loop device, click to read more about loop device. More about loop device.

Too fast to report a problem!

2009-12-13T23:35:00.001-08:00

Today when i tries to send SMS using gnokii from laptop with 'gnokii --sendsms' command it gives a long core dump, my bad that I didn't tries anything at my end and reported a problem on gnokii mailing list.
After a while when I tries with plug/unplug the USB cable which attached with my laptop and phone wow after this simple troubleshooting the 'gnokii --sendsms' start working.

Conclusion: Never report a problem on mailing lists but first exhausting every option at your end.

Make Your Own Holiday Cards with GIMP

2009-12-13T00:15:00.000-08:00

Make Your Own Holiday Cards with GIMP: "It's the holiday season! And regardless of which holidays you celebrate, it's a good time to connect with relatives and absent friends.

Maybe you can send them some cards! But those packaged cards... so drab, so dull. Wouldn't it be more fun to make your own? GIMP is a great tool for that..."

Slashdot Linux Story | GNOME Developer Suggests Split From GNU Project

2009-12-13T00:02:00.000-08:00

Slashdot Linux Story | GNOME Developer Suggests Split From GNU Project: "'In a recent posting from Philip Van Hoof, he suggests that GNOME split off from the GNU Project and has proposed a vote. He was informed he will need 10% of members to agree for a vote to be put forth. At the same time, David Schlesinger (on the GNOME Advisory Board) has agreed on a vote. Stormy Peters said she doesn't agree with this, but then gave everyone instructions on how to proceed with a vote. She mentioned that roughly 20 members are needed to agree.'"

Inserting character at some location using sed

2009-12-11T21:57:00.000-08:00

Inserting Colon ":" after every 2nd digit

Before insertion: 0022938bdea4
After insertion: 00:22:93:8b:de:a4

Method 1: This will also insert Colon in the end
sed 's/$..$/\1:/g' <<<0022938bdea4

00:22:93:8b:de:a4:

Method 2: This will work fine without doing the ending colon.
sed -e 's/$..$/\1:/g' -e 's/.$//' <<<0022938bdea4
00:22:93:8b:de:a4

Method 3: Same as Method 2
a=$(sed 's/$..$/\1:/g' <<<0022938bdea4); echo "${a:0:${#a}-1}"
00:22:93:8b:de:a4

Doing it on a file containing the data

while read file; do sed -e 's/$..$/\1:/g' -e 's/.$//' <<<"$file";done < mac_addresses.txt

Creating tar archive of the directories

2009-12-11T20:55:00.000-08:00

Below is the script for creating .tar archives of the directories containing files, I have coded this script to create .tar archive of the RADIUS bill files.

This script simple create .tar (without compressing it) and later gzip filename could be used to compress the .tar files.

Script require one argument in the form of YYYYMM to create tar archive of all the directories for the specific month of the year.

For example to run, in the current directory

./billfiles 200912 <---will create .tar archives of all the directories in the current directory which have name like 200912*

The script

#!/usr/bin/bash
# Author: Askar Ali Khan
# Date: 2009-02-10
# Purpose: To create tar of bill files
# billfiles

SOURCEDIR="/export/home/backup_billdb/bb_bill_backup"

if [ ! "$1" ]
then
echo "Must provide correct month"
echo "Format: YYYYMM Eg, 200901"
exit 0
else

if [ ! -d "$SOURCEDIR"/"$1" ]
then
echo "Directory does not exists,creating ...."
mkdir "$SOURCEDIR"/"$1"
else
echo "Directory already exists"
exit 0
fi

# Creating tar
for f in "$1"*
do
echo "Making $f.tar, please wait..."
tar cvf "$SOURCEDIR"/"$1"/"$f".tar "$f"
done

fi

New day!

2009-12-09T22:56:00.000-08:00

I am feeling sleeping coz last night my daughter Ayesha was not feeling well and keep awaking all night. Well this is what usually kids do in this age, when its time to sleep they wake up :)
And this is what fun part of life, to sacrifice your sleep for your beloved ones.
Lot of work to do at work, today we have to finalize the shifting of Broadband users to new AAA which were previously made available by moving all the Narrowband users to another AAA.
I have already created all the required charge policies and services so that during time we do not have to waste time on making them.

I have still do modify the manual provisioning scripts to work with Oracle, as the old BB AAA have IBM IDS backend while this one having Oracle 9i.

I wouldn't be difficult to as I have already modified the "Close Account" script to use Oracle and only left the "Create Account" script.

My daughter Ayesha growing

2009-12-09T08:04:00.000-08:00

My beloved daughter Ayesha is now almost one year and 2 months old and she is learn fast, walking by her own :)
Its really a fun watching her learn a little thing and walk, smile. Its all about her after I get back to home after work.

Google Dictionary

2009-12-08T21:32:00.001-08:00

Recently Google launches free online dictionary Google Dictionary. So google is going to give a tough time to work/meaning providers :)
I think that the really interesting thing is how they've integrated Google Translate into the drop down language list. Absolutely beautiful. Very useful. Nice work.

Google Chrome Browser for Linux

2009-12-08T21:12:00.000-08:00

Finally google release BETA version of chrome browser for Linux and OSX plateform, I have just install it on my laptop running Fedora 12. Installation was straight forward and as usual google chrome is fast and kick ass browser like all other google applications (GMAIL, gtalk, maps, google search) name the few :)

Google Chrome Extensions Are Now Available is now open for Windows and Linux users — but not yet for Mac — and contains around 300 extensions.

Upgrade to Fedora 12 using preupgrade

2009-11-20T07:05:00.000-08:00

Today I have upgraded my work laptop from Fedora 10 to Fedora 12 using 'preupgrade' and guess what everything went smooth and here I am currently blogging from Fedora 12 :)

Perhaps I have upgraded to Fedora 12 on both of my work and home laptops.

Here are the steps which I followed to upgrade to Fedora 12.

1. Fedora 12 upgrade requires quit some extra space on /boot partition (which is default 200MB with fedora install), before doing the upgrade first move all the extra kernels and leave only the last working one.

2. Adjust the number of reserved filesystem blocks on /boot partition using the command tune2fs. first need to identify the block device for your /boot file system. In the example below, /dev/sda1 is the block device for the /boot filesystem.

# mount | grep "/boot"
/dev/sda3 on /boot type ext4 (rw)

Now, adjust the number of reserved blocks for the /boot filesystem using the command tune2fs

# tune2fs -r 0 /dev/sda3

3. Finally run the preupgrade command to start fetching the packages while you continue to do your work, remember the downloading will takes times depending on your Internet pipe :)

# preupgrade

Or

sudo preupgrade

4. After download finish it will ask to reboot the system and then the installation process will begin which will again takes sometime. And then only one last reboot and here is the shiny Fedora 12 Constantine Desktop :)

5. Some packages may no longer be supported by the new release. You may wish to remove these packages because they will no longer get security updates, and they may cause later conflicts with supported packages. These can be identified with the following command:

package-cleanup --orphans

Securing Solaris 10 Host using ipfilter

2009-11-14T22:18:00.000-08:00

Although the “svc:/network/pfil:default” is enabled and online on a default Solaris 10 installation, no device driver has been configured for it. So that to enable IPFilter, you’ll need to configure “pfil” so that it gets autopushed for the network drivers for which you want to enable your firewall. And then the network interfaces will need to be plumbed or replumbed.

The point to note here is that IPFilter is enabled per network device driver (hme, ge, qfe,… ).

# vi /etc/ipf/pfil.ap

and uncomment there the specific drivers you are interested in, man ipf(1M) for more.

You now have 2 choices. One : reboot. At boot time, when the “pfil” service is started, the startup script /lib/svc/method/pfil will run the autopush command on the /etc/ipf/pfil.ap file before the network interfaces are confgured so that everything will work as expected. Note that the same script will also start IPFilter with a very restrictive set of rules to cover the window of vulnerability during the time network is initialized and the “ipfilter” service is started.

Second:

svcadm enable ipfilter

autopush -f /etc/ipf/pfil.ap
ifconfig bge0 unplumb
ifconfig bge0 plumb xxx.xx.xxx.xxx netmask 255.255.255.0 up

Now you are reading to write your firewall rules.

You will find some examples of the ipf.conf configuration file in /usr/share/ipfilter/examples. Just copy one of them over /etc/ipf/ipf.conf to start playing around.

Sample firewall rules.

#
# ipf.conf
#
# IP Filter rules to be loaded during startup
#
# See ipf(4) manpage for more information on
# IP Filter rules syntax.
#
# block all inbound packets.
#
block in from any to any
#
# pass through packets to and from localhost.
#
pass in from 127.0.0.1/32 to 127.0.0.1/32
#
# allow a variety of individual hosts to send any type of IP packet to any
# other host.
#
pass in from xxx.xx.xxx.xxx/32 to any
pass in from xxx.xx.xx.xxx/32 to any
#
# Allow all ICMP
pass in proto icmp from any to any

# Allow all Radius (the localhost running Radius software for authentication)
pass in proto udp from any to any port = 1812
pass in proto udp from any to any port = 1813
pass in proto tcp from any to any port = 1812
pass in proto tcp from any to any port = 1813

# Allow all from internal LAN
pass in from xx.xxx.xxx.0/24 to any

Enabling/Disabling ipf

ipf -D disable
ipf -E enable

ipf -Fa -f /etc/ipf/ipf.conf read the ipf.conf

man ipf(1M) for more on ipf

Removing ^M (Ctrl +M) characters

2009-10-15T21:54:00.000-07:00

Time to time we have to delete ^M charaters in *nix from a files, here is a simple script which will do it fast.

#!/usr/bin/ksh
# To remove ctrl+M character from txt file in solaris
# Date: 2009-02-06
# ctrl_m.sh

if [ -f $1 ]
then
tr -d '\15' < $1 >newname
mv newname $1
fi

Script first remove the ^M characters and then move the file to same filename.

Nagios Read Only Access

2009-10-14T21:46:00.000-07:00

Today I got a task to provided Nagios Read Only Web access to Contact Centres, and Google for a 2 minutes tells that a nice guy Derrick have written a readonly cgi patch for Nagios.

When I tries to patch the Nagios source it give error...

Reversed (or previously applied) patch detected! Assume -R? [n]

Which mean I did have missed something "ChangeLog" between Nagios version 3.0.x to 3.2.x, hey no more manual patching is required if you are running latest version of Nagios, as the Nagios Team have included the patch into the Nagios Core :)

So all one have to do is to add all the users to Nagios cgi.cfg file directive...

authorized_for_read_only=username

That's all, thumb up for Derrick for the nice patch and thanks to Nagios team for including it in the Core.

Installing configuring Gnokii on Linux

2009-10-13T02:04:00.000-07:00

Gnokii provides tools and a user space driver for use with mobile phones under various operating systems (most testing is done under Linux but also Solaris, *BSD family and MS Windows families are known to work. Using Gnokii one can send/receive SMS, phonebook, call management and others.

Installation from rpm manager (yum)

Gnokii package is available via most of Linux distro repository, on Fedora 10 the below will install the gnokii package if not then do the installation from source.

yum install gnokii

Installing from Source:

1. Download the gnokii source download.
2. Untar the source and change (cd) to gnokii source directory

Run...

./configure (to configure)
make (to compile)
make install (to install the binaries)

Copy the example config file for gnokii from the Docs/sample/ directory to your home directory:

$ cp Docs/sample/gnokiirc ~/.gnokiirc

If you copied the .gnokiirc file to your home directory (not root) then do not forget to add your shell user account to uucp otherwise you wouldn't able to use gnokii due to permission problem on serial device you setup in .gnokiirc file.

$ groups
askar wheel uucp

I have tested Gnokii with my Motorola L6/L7 cell phones check gnokii.org whether your phone is supported or not. (Tip.

Configuration.

Gnokii uses gnokiirc file for all this configuration, if gnokii has been installed via package manager then most probably it may have installed a /etc/gnokiirc file, the settings in this file will be used in the absence of a .gnokiirc file in your home directory.

Below is the minimum setting we need.

Note: usually you only need to edit the port and model part only

[global]
port = /dev/ttyACM0 # Set to port on which your phone is connect Tip: check /var/log/messages ]
model = AT
initlength = default
connection = serial
use_locking = no
serial_baudrate = 19200
smsc_timeout = 10
[xgnokii]
allow_breakage = 0
[gnokiid]
bindir = /usr/sbin/
#[connect_script]
#TELEPHONE = 12345678
[disconnect_script]
[logging]
debug = off # Turn it on for debugging
rlpdebug = off
xdebug = off

While phone is connected and /etc/gnokiirc or .gnokiirc has been setup properly.

2. Check if you phone has been recognize by gnokii.

gnokii --identify

GNOKII Version 0.6.27
IMEI : IMEI359411000810925
Manufacturer : Motorola CE, Copyright 2000
Model : GSM900","GSM1800","GSM1900","GS
Product name : GSM900","GSM1800","GSM1900","GS
Revision : R4513_G_08.B7.DCR_R

This is what I get for my Motorola L7 connected with via USB cable with my laptop running Fedora 10.

Note: you should see gnokii identified your cellphone/gsm modem, if you don't see it, update your ~/.gnokiirc or /etc/gnokiirc to suit your need

Note: During testing use 'root' account or you will need read/write permissions on whatever serial port you specify in /etc/gnokiirc or .gnokiirc file.

Using Gnokii

All the below information and more can be found here.

Backup & Restoration of phonebook on phone SM card using gnokii

Backup

gnokii --getphonebook SM 1 end --vcard > myphonebook.vcf

Restore

gnokii --writephonebook --vcard \< myphonebook.vcf

Handling calls

To dial a voice call:

gnokii --dialvoice 12345678

SMS Sending and Receiving

Use smsd if you need both to send and to receive SMS. You can use it with a file or a database backend.

If you only need to send, you can also use gnokii --sendsms, which reads message body from stdin.

Example:

echo "This is a test message" | gnokii --sendsms +12345678

Or

gnokii --sendsms +12345678
type your text and press

Ctrl+d to exit.

You can also use the utils/sendsms bash script that uses a text based interface using dialog as a more friendly frontend to gnokii --sendsms, allowing you to pick recipient numbers from your phonebooks instead of typing them on the command line.

In my next article you can learn how to use Gnokii + Nagios for sending SMS Notifications from Nagios whenever there is problem with any of the monitored host/service

SUSE Studio

2009-10-11T00:16:00.000-07:00

SUSE Studi o is a ...

SUSE Studio is a simple and fast appliance builder.
It provides an easy to use, web-based user interface and will run in your browser without other needed software.
One great feature is the SUSE Studio Testdrive. You can boot, configure and test your appliance in a browser window without download.

I have used to to create customize Suse (Gnome Desktop) and Minimal X Vmware images which later I have booted with Virtualbox. One can easily convert images created for vmware to virtualbox.

I like Suse Studio and its kinda revolution in the field of OS.

Checking invalid SSH attempts

2009-10-05T10:29:00.000-07:00

Running the following will gives the unique count of invalid SSH attempts on Linux server.

sudo awk 'gsub(".*sshd.*Failed password for (invalid user )?", "") {print $1}' /var/log/secure | sort | uniq -c | sort -rn | head -10

Or all of the /var/log/secure* files

sudo awk 'gsub(".*sshd.*Failed password for (invalid user )?", "") {print $1}' /var/log/secure* | sort | uniq -c | sort -rn | head -10

Domain name resolutions using 'host' command in Linux

2009-09-28T23:00:00.000-07:00

host - DNS lookup utility

host is a simple utility for performing DNS lookups. It is normally used to convert names to IP addresses and vice versa.

1. In this example we are asking host to give us the IP of www.askarali.org

host www.askarali.org
www.askarali.org has address 202.125.140.141

2. For more detailed output use -v or -d switch

host -v askarali.org
Trying "askarali.org"
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 58441 ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 2 ;; QUESTION SECTION: ;askarali.org. IN A ;; ANSWER SECTION: askarali.org. 600 IN A 202.125.140.141 ;; AUTHORITY SECTION: askarali.org. 600 IN NS dns00.beaconet.net. askarali.org. 600 IN NS dns01.beaconet.net. ;; ADDITIONAL SECTION: dns00.beaconet.net. 85792 IN A 202.125.140.139 dns01.beaconet.net. 85792 IN A 202.125.140.138 Received 130 bytes from 203.99.163.189#53 in 174 ms Trying "askarali.org" ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 5014 ;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0 ;; QUESTION SECTION: ;askarali.org. IN AAAA ;; AUTHORITY SECTION: askarali.org. 600 IN SOA dns00.beaconet.net. postmaster.askarali.org. 200803202 28800 7200 2419200 86400 Received 95 bytes from 203.99.163.189#53 in 19 ms Trying "askarali.org" ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 9732
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 3

;; QUESTION SECTION:
;askarali.org. IN MX

;; ANSWER SECTION:
askarali.org. 600 IN MX 10 smtp.askarali.org.

;; AUTHORITY SECTION:
askarali.org. 600 IN NS dns00.beaconet.net.
askarali.org. 600 IN NS dns01.beaconet.net.

;; ADDITIONAL SECTION:
smtp.askarali.org. 600 IN A 203.148.64.29
dns00.beaconet.net. 85792 IN A 202.125.140.139
dns01.beaconet.net. 85792 IN A 202.125.140.138

Received 151 bytes from 203.99.163.189#53 in 12 ms

3. For particular type of DNS record for example NS, MX, SOA, CNAME use the -t option. In the following example will search for name server (NS), mail exchanger (MX) and Start of Authority (SOA) for askarali.org

host -t NS askarali.org
askarali.org name server dns00.beaconet.net.
askarali.org name server dns01.beaconet.net.

host -t MX askarali.org
askarali.org mail is handled by 10 smtp.askarali.org.

host -t SOA askarali.org
askarali.org has SOA record dns00.beaconet.net. postmaster.askarali.org. 200803202 28800 7200 2419200 86400

For more information on host read the RTFM (man host)

2009-09-27T21:37:00.000-07:00

Installing NRPE in Solaris 10

1. Install NRPE and dependencies using blastwave repository, if new to blastwave then follow the howto use the repostory for installing third party and GNU tools in Solaris.

/opt/csw/bin/pkgutil -i nrpe

2. Download manifest files
wget -P /tmp/ http://www.terdmonk.com/files/solaris/nagios/nrpe_smf.zip

# cd /tmp
# unzip nrpe_smf.zip
# mv nrpe/manifest/nagios-nrpe.xml /var/svc/manifest/network
# mv nrpe/method/nagios-nrpe /lib/svc/method/nagios-nrpe
# svccfg import /var/svc/manifest/network/nagios-nrpe.xml

3. Create nrpe.cfg file
mv /opt/csw/etc/nrpe.cfg-sample /opt/csw/etc/nrpe.cfg

4. Fixing permissions
chown nagios:nagios /opt/csw/etc/nrpe.cfg
chmod ug+x /lib/svc/method/nagios-nrpe

5. Starting NRPE daemon
# svcadm disable nrpe
# svcadm enable nrpe

That's all confirm that nrpe is running and listening on port 5666

# svcs | grep nrpe
online May_29 svc:/network/nagios/nrpe:default

# netstat -a | grep 5666
*.5666 *.* 0 0 49152 0 LISTEN

2009-09-27T09:00:00.000-07:00

Booting Linux Over HTTP

Wow one now can boot Linux over HTTP with BKO, sound very interesting project soon I'll give a try to it.
All one need a machine and have to dowload a small bootable 56K program (pgxe) which take care of network connectivity. After downloading the pgxe have burn it to CD, or copy to USB stick.

Linux Distributions supported or available to boot over HTTP..
1. Debian : Debian live
2. Ubuntu : 9.04
3. Damm Small Linux : Lightweight linux distribution with GUI.
4. Knoppix : Knoppix 5.0.1 English.
5. Fedora 11 Live CD : Currently only single user mode is working. (Working on complete live CD)

2009-09-27T06:59:00.000-07:00

Squid configurations examples

Here are the collection of Squid Configurations contributed by me on wiki-squid intended to demonstrate the flexibility of Squid.

SquidAndOpenLDAP
In this example a squid installation will use LDAP to authenticate users before allowing them to surf the web. For security reasons users need to enter their username and password before they are allowed to surf the internet.

SquidAndMysql
In this example a squid installation will use Mysql to authenticate users before allowing them to surf the web. For security reasons users need to enter their username and password before they are allowed to surf the internet.

SquidAndRADIUS
In this example a squid installation will use RADIUS "squid_radius_auth" Squid RADIUS authentication helper to authenticate users before allowing them to surf the web. For security reasons users need to enter their username and password before they are allowed to surf the internet.

2009-09-27T06:51:00.000-07:00

Installing Postfix in Solaris 10

Solaris 10 like all other Unix/Linux comes with sendmail by default, however managing sendmail is difficult that's where Postfix come into picture.
Postfix is easier to install and configure in Solaris 10 this is how I did it a while back.
Hope this will also help other fulks looking for installing Postfix in Solaris 10.

Securing the BIND using "Views"

2009-09-16T02:03:00.000-07:00

BIND server is not without centain vulnerabilities, a bad guys can turn misconfigured bind into launching platform for DDOS attacks. Vandals can also take advantage of an insecure BIND configuration and poison the cache, thus permitting host impersonation and redirecting legitimate traffic to black holes or malicious hosts.

Here you will learn how to secure BIND using views, the sample config is for cache only named server and can easily be modified and used for your primary DNS server which could be authorized for your company domain.

named.conf

acl "trusted" {
// Place our internal and DMZ subnets in here so that
// intranet and DMZ clients may send DNS queries. This
// also prevents outside hosts from using our name server
// as a resolver for other domains.
192.168.1.0/24 // Replace it with your network
localhost;
};

logging {
category lame-servers {null; };
};

options {
directory "/var/named";
dump-file "/var/named/data/cache_dump.db";
statistics-file "/var/named/data/named_stats.txt";
/*
* If there is a firewall between you and nameservers you want
* to talk to, you might need to uncomment the query-source
* directive below. Previous versions of BIND always asked
* questions using port 53, but BIND 8.1 uses an unprivileged
* port by default.
*/
// query-source address * port 53;
// Prevent DoS attacks by generating bogus zone transfer
// requests. This will result in slower updates to the
// slave servers (e.g. they will await the poll interval
// before checking for updates).
notify no;

// Generate more efficient zone transfers. This will place
// multiple DNS records in a DNS message, instead of one per
// DNS message.
transfer-format many-answers;

// Set the maximum zone transfer time to something more
// reasonable. In this case, we state that any zone transfer
// that takes longer than 60 minutes is unlikely to ever
// complete. WARNING: If you have very large zone files,
// adjust this to fit your requirements.
max-transfer-time-in 60;

// We have no dynamic interfaces, so BIND shouldn't need to
// poll for interface state {UP|DOWN}.
interface-interval 0;
};

//
// a caching only nameserver config
//
controls {
inet 127.0.0.1 allow { localhost; } keys { rndckey; };
};

view "trusted" IN {
// Our internal (trusted) view. We permit the internal networks
// to freely access this view. We perform recursion for our
// internal hosts, and retrieve data from the cache for them.
match-clients { trusted; };
recursion yes;
additional-from-auth yes;
additional-from-cache yes;
// Link in our zones
zone "." IN {
type hint;
file "named.ca";
};

zone "localdomain" IN {
type master;
file "localdomain.zone";
allow-update { none; };
};

zone "localhost" IN {
type master;
file "localhost.zone";
allow-update { none; };
};

zone "0.0.127.in-addr.arpa" IN {
type master;
file "named.local";
allow-update { none; };
};

zone "0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa" IN {
type master;
file "named.ip6.local";
allow-update { none; };
};

zone "255.in-addr.arpa" IN {
type master;
file "named.broadcast";
allow-update { none; };
};

zone "0.in-addr.arpa" IN {
type master;
file "named.zero";
allow-update { none; };
};
};
view "badguys" IN {
// Our external (untrusted) view. We permit any client to access
// portions of this view. We do not perform recursion or cache
// access for hosts using this view.
match-clients {"any"; }; // all others hosts
recursion no;
additional-from-auth no;
additional-from-cache no;

// Link in our zones
zone "." IN {
type hint;
file "named.ca";
};

zone "localdomain" IN {
type master;
file "localdomain.zone";
allow-update { none; };
};

zone "localhost" IN {
type master;
file "localhost.zone";
allow-update { none; };
};

zone "0.0.127.in-addr.arpa" IN {
type master;
file "named.local";
allow-update { none; };
};

zone "0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa" IN {
type master;
file "named.ip6.local";
allow-update { none; };
};

zone "255.in-addr.arpa" IN {
type master;
file "named.broadcast";
allow-update { none; };
};

zone "0.in-addr.arpa" IN {
type master;
file "named.zero";
allow-update { none; };
};
};
// Create a view for all clients perusing the CHAOS class.
// We allow internal hosts to query our version number.
// This is a good idea from a support point of view.
view "external-chaos" chaos {
match-clients { any; };
recursion no;

zone "." {
type hint;
file "/dev/null";
};

zone "bind" {
type master;
file "db.bind";
};

allow-query {
trusted;
};
allow-transfer {
none;
};
};

include "/etc/rndc.key";

The db.bind zone file

The db.bind zone file is used to track miscreants who attempt to query the CHAOS TXT records version.bind and authors.bind. You can also use this zone file to change the strings returned by such queries. Using the "version" directive in the options stanza will block the version.bind query, but it will not log such attempts.

; @(#)db.bind v1.2 25 JAN 2001 Rob Thomas noc@cymru.com ; $TTL 1D $ORIGIN bind. @ 1D CHAOS SOA localhost. root.localhost. ( 2001013101 ; serial 3H ; refresh 1H ; retry 1W ; expiry 1D ) ; minimum CHAOS NS localhost.

version.bind. CHAOS TXT "BIND 9.1.3+robhacks" authors.bind. CHAOS TXT "are better coders than I. :)"

Converting VMware image to VirtualBox

2009-09-15T00:53:00.000-07:00

VirtualBox can run VMs created by VMware Workstation or Server for this you need to import vmdk files using the following procedure

* Start Virtual Box

* Goto File > Virtual Disk Manager

* Click Add. Locate and select the copied .vmdk file. Click OK.

* Create a New VM as usual using the added vmdk file

* Boot the VM

OpenSolaris vs. Linux, For Linux Users

2009-09-14T22:36:00.000-07:00

With Sun busy being swallowed up by Oracle, should Linux geeks pay any interest to OpenSolaris? TuxRadar put together a guide to OpenSolaris's most interesting features from a Linux user's perspective, covering how to get started with ZFS and virtualisation alongside more consumer-friendly topics such as hardware and Flash support.

Linux Tip/Tricks continue...

2009-09-14T01:03:00.000-07:00

Command to search packages with duplicats sort them

rpm -qa --qf "%{name} %{epoch}:%{version} - %{arch}\n" | sort

Creating thumbnails on the fly using ImageMagick

for img in *.jpg; do convert -resize 200 "$img" thumb_"$img";done

Renaming all files in current directory to filename.orig - you should use quotes around $file if your filenames contain spaces

for file in *; do mv $file $file.orig; done

Chop value to two decimal places using 'bc'

printf "%.2f\n" $(echo $'scale=2\n'"1.006"'+.005' | bc)

Finds all files over 20,000KB (roughly 20MB) in size and presents their names and size in a human readable

find / -type f -size +20000k -exec ls -lh {} \; | awk '{ print $9 ": " $5 }'

OR

find / -type f -size +20M -exec ls -lh {} \;

Find some text in lot of files and then delete those files

grep -rls "PATTERN" . | tr '\n' '\0' | xargs -0 rm

Linux Tip/Tricks continue...

2009-09-12T00:36:00.000-07:00

To print unique IPs from squid access.log and sort them

awk '{print $3}' /var/log/squid/access.log.0 | sort -ut . -n -k 1,1 -k 2,2 -k 3,3 -k 4,4 | nl

This one doesn't sort but gives uniq ips with line number.

awk '{print $3}' /var/log/squid/access.log.0 | sort -u | nl

To put some text on every blank line

sed 's/^/some text/' urls > newfile

To kill the process

ps -ef | grep xterm | awk '{print $2}' | xargs kill -9

Check if the machine is live, useful for use in scripts.

if ping -c 1 mydomain.com >/dev/null 2>&1; then echo "live";else echo "dead";fi

Linux Tip and Tricks continue...

2009-09-11T00:08:00.000-07:00

Continuation with the day to day commands that I have compiled over the time.

Removing commented lines (starting with #) from a file
grep -v '^#' squid.conf > squid.conf.new

To remove empty lines from a text file. I've been using sed with
sed '/^ *$/d' squid.conf.new > squid.conf.nospace

Do the same thing with sed in one line
$ sed '/^#/d' squid.conf.default | sed /^$/d > squid.conf.new

To remove all commented lines (starting with #) and blank lines from a file
sed -e '/^$#\|$$/ d' squid.conf.default > squid.conf.new

Same thing using egrep
egrep -v '^(#|$)' squid.conf.default > squid.conf.new

OR
grep '^[^#]' squid.conf > squid.conf.new

Hammad got admission in BCS

2009-09-10T10:35:00.000-07:00

Hammad got admission in Mardan Univeristy BCS, he is now university going boy :)

2009-09-10T10:22:00.000-07:00

It was another cool day of Ramadan, nothing much at work (in this holy month working get bit slow).
In the morning did a tape backup of AAA data, backup taking is already automated including backing up to external machine and restoring.
Tomorrow there is a meeting call on the proposed expansion BRAS project in the CDDT building H9, Mr. Imtiaz (GM IP OPs MMBB Core) will chair the meeting.

Reunion

2009-09-09T10:43:00.000-07:00

Today after a long time I have contact one of my childhood friend Shamsul Qamar. We lived and grow up in Mirpurkhas Sugar Mills colony where both of our fathers were working.Its was very nice to talk to one childhood friend, it reminds the great and ever lasting memories of childhood.He is working in sugar industry like his father and lives with his family in Torro (Mardan), Shams promise to visit me during coming Eid and I am looking forward :)

Linux commands

2009-09-07T23:17:00.000-07:00

Here are the series of commands bash tip/tricks which I have learn time to time while working.

# To report oldest file in a directory
ls -1rt | head -n1

# To rename lot of files to different name
for i in `find -type d`; do mv $i `basename $i (ska)`; done

# Very handy while copying ssh public key to remote server, where one have to create .ssh directory, authorized file, keeping the permissions straight.

mkdir .ssh --mode 700 ; touch .ssh/authorized_keys ; chmod 644 .ssh/authorized_keys

# Whats the quick way to remove .blah.com from mycomany.blah.com ?

$str=~s/\.blah\.com//i

# Finding files and then deleting them

find /software/ftp/ -name '*.exe' -print0 | xargs -0 rm -f

Or much better to use the -exec action:

find /software/ftp/ -name '*.exe' -exec rm {} \;

# Extract url for path to Full version of last kernel for each branch

wget -O /dev/stdout http://www.kernel.org/ 2>/dev/null | grep ">F<"|head |awk -F "\"" '{ print $2 }' # This version will download the kernels wget -O /dev/stdout http://www.kernel.org/ 2>/dev/null | grep ">F<"|head |awk -F "\"" '{ print $2 }'|while read line;do if [ -n "$line" ]; then wget -c "http://www.kernel.org$line";fi;done#

#Find files that has been access +n days ago and then remove it.

find . -mtime +180 -exec ls -lh {} \;
find . -mtime +180 -exec rm -f {} \;

Updating Nagios package

2009-09-07T02:08:00.000-07:00

Today at last I have updated the Nagios package which was delayed from quit sometime.

Updating was quite transparent, only the index.php page has been replaced. Actually instead of displaying the default Nagios index page I have changed it to display the "Host Group Summary" page to all using Nagios web UI.

So all I have to do to change

/usr/share/nagios/index.php (path might be different if installed from source)

frame src="main.php" name="main" frameborder="0"

To

frame src="/nagios/cgi-bin/status.cgi?hostgroup=all&style=summary" name="main" frameborder="0"

Sunday is family day

2009-09-06T04:09:00.000-07:00

Its Sunday so like every Sunday its family day. On Sunday night i usually watch movie but due to ramadan karim I am not watching movies.
Yesterday i was watching news and then while checking email found an email from Pat (founder of Slackware, a oldest serviving Linux distro). Wow Pat and team released Slackware 13.0 in 2009-08-27.
Its always nice to see Pat working hard and releasing the stable versions of slackware.
Slackware is my favourite Linux distro, and i used it exclusively as my home and work desktop OS for almost 3 years.
However due to work nature (need to work more) got switched to Fedora. Switching off from Slackware doesn't mean that I do not like it. I learn Linux with slackware, and I am still a proud slacker :)
Well Fedora is bit easier to maitain and installing packages is also easy using YUM.

Ayesha wake up in Peshmani

2009-09-03T22:43:00.000-07:00

Today at the time of Peshmanay my daughter Ayesha wake up, normally she sleeping at that time while me and my wife talk our food. Well long story short then she wants us to play and listen to her :)
It took another hour and half when she again went sleep.

Ayesah is almost 11 month old now and she is getting very naughty and its very hard for both of us to keep and eye on her not just an eye but these age babies require a very close watch and i am thinking to monitor her via Nagios http://www.nagios.org :)

Love Open Source

2009-09-03T22:38:00.000-07:00

I love open source, not because this community provide free and the best software but bcoz they way this community works. I wish one day all the evil IT empires will open source there fat ass softwares.

Monitoring

2009-09-03T22:31:00.000-07:00

You either fight fires all day, or build a flame resistant structure. Monitoring is the smoke detector. Notification is the alarm system. Fireman, or Fire Marshall - take your pick...

If you are not monitoring, then you are not managing.

2009-09-02T00:31:00.000-07:00

I almost forget to talk about my daughter, whom is the centre of gravity these days.
I wonders how smart she is getting day by day, while we (me and my wife) sit during the iftar she is the one to handle :)
She tries to get her hands to each pot she see and if Ayesha got spoon in her hands then its drums all around.
Ayesha mother wait till I come back from work so that she could start working in the kitchen and i could look after Ayesha.
We father and daughter went out after the prayers of Asar. Ayesha loves going out (probably she got bored staying at home all day).

2009-09-02T00:25:00.000-07:00

Its the Holy month of Ramadan and during this month we fast. Tell you what I got too lazy coz of level of energy :)
As Allah says this month is for me so we fast with devotion to get all out of the this holy month in term of recetation of Quran, praying 5 times (this we do the whole year), the prayers of travis.
After the whole day of fasting its really a blessing when one Iftar, this is the real time to thanks Allah for all his givings.
During the month of Ramadan one could realize for can imagine a bit the feelings of one who's hungry.
This month is the month of brotherhood, love, devotion.

2009-07-22T07:10:00.000-07:00

Today nagios has been successfully integrated with gnokii SMS gateway. Now each work group will receive SMS notification in case of problem with any host/service in our infra.
There is still plenty of work to do, for example need to add lot of devices/hosts monitoring.

2009-07-20T21:13:00.000-07:00

After two hot summar days today weather is kinda pleasant and clouds are hanging on the sky hopes there will be some rain fall to turn the weather more pleasant.
Today my two nephews Hammad & Ahrar Khan's F.Sc result were announced and with the grace of Almighty Allah both passed the exams with bright colors.
Ahrar have got 359 out of 550 in F.Sc Part 1 so he will sit in F.Sc Part II very soon.
Hammad Khan have got 621 out of 1050 in F.Sc part II.
Whole the family down in Mardan are very happy with the success of our kids :)
Hammad Khan is interested to get admission in the BCS computer, hope he will got admission in some decent university.

2009-07-18T23:19:00.000-07:00

Ayesha is sleeping so I have time to check my emails and slashdot. On Off day like sunday its all about Ayesha, me and my wife. We spend all time together sometime go outing/shopping.
However as its too hot in here these days we prefer to spend time inside.
Ayesha love to go out, (all the kids love to go outside :))

2009-07-13T22:02:00.000-07:00

Its working, my fault I was too quick to check my web blogs.
Yesterday I have added few more hosts in nagios, most of them where Linux hosts.
For SMS notifications from nagios I have to work on integrating nagios with our company SMS system.