Extending LVM disk space

Add the new disk drive to the system, you need to reboot the machine and configure the hardware RAID if required.

Add the new disk to Volume group

For e.g.: if the disk is HP with Smart array

# pvcreate /dev/cciss/c0d1
# vgextend <volume_group_name> /dev/cciss/c0d1

Extend the Logical volume:
# lvextend -L<+mention_the_size> /dev/<volume_group>/<logical_volume>
eg: # lvextend -L+25G /dev/localhost/var
       # lvextend -L+10G /dev/localhost/home

Resize the file system:
# resizefs <file_system>
# resizefs /dev/mapper/localhost-var
# resizefs /dev/mapper/localhost-home


Converting LVM virtual machine storage to image

To convert the LVM disk to qcow2 formatted disk image,

Use lvdisplay to get the Logical volume name

$ sudo lvdisplay

Use qemu-img to convert to the required image format

# qemu-img convert -O qcow2 /dev/mapper/lv_name <destination_file>.qcow2


# qemu-img convert -O qcow2 /dev/mapper/disk1 disk1.qcow2

This will be useful to replicate the virtual machines to other hardware.