[CentOS] resize LVM (ext3)

Luciano Rocha strange at nsk.no-ip.org
Wed Oct 29 12:12:21 UTC 2008

On Wed, Oct 29, 2008 at 12:58:32PM +0100, David Hláčik wrote:
>    1. How can i be sure that i will shrink ext3 to exact size 80GB and that

resize2fs $dev 80G

Then, to be sure of the real size:
blks=$(tune2fs -l $dev | awk -F: '/Block size/ { print $2/512 }')
fssize=$(tune2fs -l $dev |
  awk -v bs=$blks -F: '/Block count/{print $2*bs}')

Now, $fssize has the complete size in bytes. Verify it:
echo $fssize

Now, for lvresize:
lvresize -L 80G system/home

Verify that the printed target size matches the wanted value.

>    3. Or can i just use lvreduce and my ext3 will shrink automatically?

NO! lvreduce doesn't care about what's inside, and will happily lose

>    4. Do i need to umount system/home when resizing?

Yes, and you must do a full fsck also:

e2fsck -f /dev/system/home

Luciano Rocha

-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 197 bytes
Desc: not available
URL: <http://lists.centos.org/pipermail/centos/attachments/20081029/a3b705b0/attachment.sig>

More information about the CentOS mailing list