This is more of Resize LVM
I have tested this on CentOS 5.5. Since this is root partition modification, I’ll recommend to keep config backup before proceeding.
create new partition (partition id should be 8e Linux LVM)
ADD PHYSICAL VOLUME
pvcreate /dev/new_partition
Verify new physical volume
pvdisplay
Or
pvscan
Extend existing VOLUME GROUP
vgextend VolGroup00 /dev/xvda3
make sure vg free size is = new partition size using vgdisplay command
Extend existing LVM by adding new partition
lvextend /dev/VolGroup00/LogVol00 /dev/xvda3
make sure lv size is increased, use lvdisplay
RESIZE FILE SYSTEM
Reboot Linux to init1
umount /dev/VolGroup00/LogVol00
fsck -f /dev/VolGroup00/LogVol00
Mount / partition or reboot to init1 for following command to run.
resize2fs /dev/VolGroup00/LogVol00
Now you may reboot & check / partition size.