Adding additional disk to Windows XP KVM guest

Need additional disk space on your KVM guest OS?, here how I added an additional disk to Windows XP guest OS. Note I am using logical volumes for the storage.

1) Create a LVM which will then be added to guest OS as an additional hard disk
On host run

#  lvcreate -L 20G -n kvm7 vg_kvm

-L 20G is the size of the new LVM
-n kvm7 is the name of the new LVM
vg_kvm is the volume group name

2) Next stop the guest OS (virsh destroy vmName may be? :)

3) Edit the guest OS configuration file by adding a new disk section

# virsh edit

In my case the existing drive "C" on windows XP was defined as dev="hda"

<disk type='block' device='disk'> <driver name='qemu' type='raw' cache='none'/> <source dev='/dev/mapper/vg_kvm-kvm6'/> <target dev='hda' bus='ide'/> <alias name='ide0-0-0'/> <address type='drive' controller='0' bus='0' unit='0'/> </disk>

 The additional drive will be "hdb", ended by adding the following to the configuration file

<disk type='block' device='disk'> <driver name='qemu' type='raw' cache='none'/> <source dev='/dev/mapper/vg_kvm-kvm7'/> <target dev='hdb' bus='ide'/> <alias name='ide0-0-1'/> <address type='drive' controller='0' bus='0' unit='1'/> </disk>

Save the configuration and exists

4) Start the guest OS "virsh start , once the vm fully started initialize the new disk by 
Right click My computer -> Manage -> Disk Management