[linux-lvm] Different sizes being reported for logical volume after extend

[Magnus Hyllander <mhylist1@hyllander.org>]

  Hi,

I have a little problem with a logical volume: in short, the size of the 
volume is different depending on if I boot from the FC5 rescue CD or 
from the installed FC5.

I have two mirrored disks. On the mirror I have created a logical volume 
/dev/VolGroup00/LogVol00 which contains the root filesystem. Initially I 
made the volume 4GB. Later I needed more space, so I decided to extend 
the volume to 8GB. I booted from the FC5 rescue CD and ran the following 
commands:

    dmraid -a y
    lvm vgscan
    lvm vgchange -a y
    lvm lvextend -L +4G /dev/VolGroup00/LogVol00
    fsck /dev/VolGroup00/LogVol00
    resize2fs /dev/VolGroup00/LogVol00

So far so good. Then I rebooted the system from disk and got the 
following error:

    Checking filesystems
    /dev/VolGroup00/LogVol00: The filesystem size (according to the
    superblock) is 2097152 blocks
    The physical size of the device is 1048576 blocks
    Either the superblock or the partition table is likely to be corrupt!

    /dev/VolGroup/LogVol00: UNEXPECTED INCONSISTENCY, run fsck manually.

I entered the system administration mode and checked the size of 
/dev/VolGroup/LogVol00 with "lvm lvs": 4.00G
Strange... so I booted with the rescue CD again and checked the size 
once more from the rescue environment: 8.00G.

So it seems that when I boot the system normally it doesn't "see" that 
the size of the logical volume has changed. Can someone explain this, 
and hopefully help me fix the problem?

/Magnus