How to increase disk size using logical volume manager

Okay, so you added extra space on a VM or a new disk on the physical server, follow the steps below to increase the logical volume without reboot.

check the disk and current volumes

fdisk -l

Run fdisk on the disk (in this case it was sda)

fdisk /dev/sda

Check free unpartitioned space

F

print the partition table

p

create a new partition

n

select primary partition

p

select the partition number(in this case it was 3)

3

write changes to the partition table (ignore errors if any)

w

run partx to view the disk partition without rebooting if the fdisk command above throws a message that the new partition table will be available after reboot

partx -v -a /dev/sda

create a physical volume using /dev/sda3

pvcreate /dev/sda3

display volume group information (check for Free PE / Size)

vgdisplay

Extend the Volume Group (in this case vg0)

vgextend vg0 /dev/sda3

display volume group information again (check for Free PE / Size)

vgdisplay

*note the - Free  PE / Size  

Run lvdisplay to list all logical volumes and then run it again with the volume you wish to extend

lvdisplay /dev/vg0/root

* Note the - Current LE

Resize the Logical Volume

lvresize -l 438 /dev/vg0/root

*The number is Free PE Current LE

OR

lvresize --size [plus]10GB /Dev/vg0/root

(replace 10GB with the amount of space you want to increase)

Run the df command

df -h

Resize the partition

resize2fs /dev/mapper/vg0-root

Run df again

df -h

The disk space on the volume has increased.