Monday, September 30, 2013

Extend a volume in RedHat 6 or CentOS 6

To extend a partition on a VM on CentOS 6 or RHEL 6, do the following:

Extend the Partition in vSphere to the size that you need:

in the VM, refresh the Partition Tables by the following command:

echo 1 > /sys/block/sda/device/rescan
Run fdisk to create a new primary partition:

fdisk /dev/sda

Press p to print the number of partitions
Press n to create a new primary patition
Press p for primary
The partition number should automatically be selected, and press enter twice to accept the beginning and ending blocks on the free space.
Press w to write the changes.

Reboot the system: shutdown -r now

Verify that the new partition exists:
fdisk -l

Convert the new partition to a physical volume:
pvcreate /dev/sda3
Extend the Physical Volume (run vgdisplay to obtain the name of the Volume Group; default is VolGroup00):
vgextend VolGroup00 /dev/sda3

Extend the Logical Volume (run vgdisplay to obtain the free space and replace # below, and lvdisplay to obtain the name of the Logical Volume; default is /dev/VolGroup00/LogVol00)
lvextend -L+#G /dev/VolGroup00/LogVol00

Expand the ext3 online using the following command (substituting your proper Volume Group and Logical Volume names):
resize2fs /dev/VolGroup00/LogVol00

Confirm that your new space is available:
df -h



This was written using VMware's KB article on the subject as a reference.

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Dustin Shaw
VCP