increasing a logical volume

Question

I need to increase the logical volume of the var directory, the maximum size of var right now is 10GB, I need to make it 50GB. I have a Centos 6 server.

The output of df -h is:

Filesystem            Size  Used Avail Use% Mounted on
rootfs                 10G   10G     0 100% /
/dev/root              10G   10G     0 100% /
none                  991M  312K  990M   1% /dev
/dev/sda2             455G  3.6G  429G   1% /home
tmpfs                 991M     0  991M   0% /dev/shm
/dev/root              10G   10G     0 100% /var/named/chroot/etc/named
/dev/root              10G   10G     0 100% /var/named/chroot/var/named
/dev/root              10G   10G     0 100% /var/named/chroot/etc/named.conf
/dev/root              10G   10G     0 100% /var/named/chroot/etc/named.rfc1912.zones
/dev/root              10G   10G     0 100% /var/named/chroot/etc/rndc.key
/dev/root              10G   10G     0 100% /var/named/chroot/usr/lib64/bind
/dev/root              10G   10G     0 100% /var/named/chroot/etc/named.iscdlv.key
/dev/root              10G   10G     0 100% /var/named/chroot/etc/named.root.key

I followed this tutorial. In order to increase the volume you have to do:

lvextend -L +40G /Path/To/var

My problem is simple, I don't know where my var is located.

If i do lvextend -L +40G /dev/root/var I get Volume group "root" not found

If i do lvextend -L +40G /dev/var I get

  Path required for Logical Volume "var"
  Please provide a volume group name
  Run `lvextend --help' for more information.

I tried every possible path, still can't find the right path to var, so where my var is located?

EDIT

If i do lvextend -L +40G /dev/root I get

  Path required for Logical Volume "root"
  Please provide a volume group name
  Run `lvextend --help' for more information.

pvs gives no output at all.

lvs gives this output No volume groups found

Solution 1

As I expected from the name /dev/root, you're not using LVM. You have a few options:

1. Reinstall
2. Hope that your partitioning scheme allows you to grow the root partition with (g)parted.
3. Create a new partition as LVM volume, create a vg and and an lv for /var and move /var over
4. Clean up the current system so you don't need the space

Options 2 and 3 are best done when booting from a rescue cd or rescue netboot.

Solution 2

Your /var is inside the root mountpoint, so you'll want to increase the size of /dev/root, if that is an LVM volume.

Comments

[Dennis Kaarsemaker]

Can you add the output of pvs, vgs and lvs please.

[mahieddine]

please read my edit sir

[vonbrand]

Or use something like parted, as OP isn't using LVM.

[mahieddine]

option 1: do you mean reinstall centos? if so what to do during the installation to insure that i'm using lvm volume? Basically i have nothing on the server right now so i can do a reinstallation