Is ext3 online LVM resize working ?

YES , if you run kernel 2.6.10 and upwards you should be able to do an online resize of your LVM partition.

Check this :


PRD01:~ # uname -a
Linux PRD01 2.6.27.19-5-default #1 SMP 2009-02-28 04:40:21 +0100 x86_64 x86_64 x86_64 GNU/Linux

( When checked in /etc/mke2fs.conf , you will see a default registration of resize_inode which also indicates that online resizing is allowed. )

Here are the steps i used to do it :

Check your filesystem first :

PRD01:~ # df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/system-root
                      9.9G  3.7G  5.8G  39% /
udev                  1.9G  120K  1.9G   1% /dev
/dev/sda2             996M   25M  921M   3% /boot
/dev/mapper/system-tmp
                      5.0G  1.2G  3.6G  26% /tmp
/dev/mapper/oracle-u00
                      9.9G  5.7G  3.8G  61% /u00
/dev/mapper/oracle-u01
                      4.0G  1.7G  2.2G  44% /u01
/dev/mapper/oracle-u02
                      148G   91G   50G  65% /u02
/dev/mapper/oracle-u03
                       30G  2.1G   26G   8% /u03
/dev/mapper/oracle-u04
                      296G   77G  204G  28% /u04

See if there is any space to give to our lvm volumes :

PRD01:~ # pvscan
  PV /dev/sdb1   VG oracle   lvm2 [599.98 GB / 105.98 GB free]
  PV /dev/sda3   VG system   lvm2 [15.00 GB / 0    free]
  Total: 2 [614.98 GB] / in use: 2 [614.98 GB] / in no VG: 0 [0   ]

Lets add 50 Gb to our /u03 location : ( be aware of the + in the command, without it , your partition will be sized 50 Gb )

PRD01:~ # lvm
lvm> lvextend -L+50000M /dev/mapper/oracle-u03
  Extending logical volume u03 to 78.83 GB
  Logical volume u03 successfully resized
lvm> exit
  Exiting.

Our LVM is resized , but the partition still needs a resize to match the volume given :

PRD01:~ # resize2fs /dev/mapper/oracle-u03
resize2fs 1.41.1 (01-Sep-2008)
Filesystem at /dev/mapper/oracle-u03 is mounted on /u03; on-line resizing required
old desc_blocks = 2, new_desc_blocks = 5
Performing an on-line resize of /dev/mapper/oracle-u03 to 20664320 (4k) blocks.
The filesystem on /dev/mapper/oracle-u03 is now 20664320 blocks long.

Now lets check if all is well :

PRD01:~ # df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/system-root
                      9.9G  3.7G  5.8G  39% /
udev                  1.9G  120K  1.9G   1% /dev
/dev/sda2             996M   25M  921M   3% /boot
/dev/mapper/system-tmp
                      5.0G  1.2G  3.6G  26% /tmp
/dev/mapper/oracle-u00
                      9.9G  5.7G  3.8G  61% /u00
/dev/mapper/oracle-u01
                      4.0G  1.7G  2.2G  44% /u01
/dev/mapper/oracle-u02
                      148G   91G   50G  65% /u02
/dev/mapper/oracle-u03
                       78G  2.1G   72G   3% /u03
/dev/mapper/oracle-u04
                      296G   77G  204G  28% /u04
PRD01:~ #

Thats all !