[linux-lvm] lvm size mismatch?

[Soon-Son Kwon]

Hi I am using lvm on debian woody.
The version would be about 1.0.x.

foo:/var# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/sda1              11G  8.1G  1.9G  81% /
/dev/vol/var           18G   16G  2.7G  85% /var
/dev/vol/home         4.9G  1.8G  3.1G  36% /home
/dev/vol/tmp          500M   61M  439M  13% /tmp
/dev/extra/data        70G  9.5G   60G  14% /data

foo:/var# du . -sh
5.4G    .
foo:/var#

Please take a look at /dev/vol/var which is 18G big and it says
16G is already used.

But when I check the disk usage by running du command, it shows
only 5.4G is used.

Then...where does this size mismatch come from?
-- 
-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-
  Shawn Soon-Son Kwon, founder and leader of KLDP
           ( http://kldp.org ,  http://kldp.net )
  Phone: 82-16-535-7282  Homepage: http://kldp.org/~kss
-*-*-*-t-h-e-*-o-p-e-n-*-s-o-u-r-c-e-*-c-o-m-m-u-n-i-t-y-