Check present logical volumes

root@abcd:/# lvs
LV   VG      Attr   LSize   Origin Snap%  Move Log Copy%  Convert
home wgkiste -wi-ao 914.13g
root wgkiste -wi-ao  13.42g
swap wgkiste -wi-ao   3.72g
root@wgkiste:/# cat /etc/fstab
# /etc/fstab: static file system information.
proc            /proc           proc    nodev,noexec,nosuid 0       0
/dev/mapper/wgkiste-root /               ext4    errors=remount-ro 0       1
/dev/mapper/wgkiste-home /home           ext3    defaults        0       2
/dev/mapper/wgkiste-swap none            swap    sw              0       0

Shrink logical volume “home”

Check out, if we have spare space on home

root@wgkiste:/# df -h
Dateisystem            Größe Benut  Verf Ben%%
Eingehängt auf /dev/mapper/wgkiste-root 14G   11G  2.6G  80% /
/dev/mapper/wgkiste-home 914G  668G  187G  79% /home

First, we have to shrink the filesystem (“ext3” in this case). For that, the filesystem must be umounted.

We are checking te current size to determine the new size.

root@wgkiste:/# lvdisplay /dev/mapper/wgkiste-home
--- Logical volume ---
LV Name                /dev/wgkiste/home
VG Name                wgkiste
LV Size                914.13 GiB

We have to switch to textconsole and login as root, not as user and su, because the users home directory is going to be umounted.

Ctrl + Alt + F1

Login as root on command prompt

/etc/init.d/kdm stop
umount /home
e2fsck -f /dev/mapper/wgkiste-home

Resize the file sstem to a good deal less than what you will shrink the logical volume to. You don’t want to run in a situation, where your filesystem is begger than the new partition size. If your EXT3 system seems bigger than the partition, your comuter wont reboot anymore, because fsck will hang! I’ve chosen a margin of 50G between the file system size and the logical volume size.

resize2fs /dev/mapper/wgkiste-home 850G
lvreduce -L 900G /dev/mapper/wgkiste-home
e2fsck /dev/wgkiste/home

Although the fsck will take a long while each time, don’t omit this step. If the resize command went  wrong, your chances to save the situation are better now than later.

Now, we can extend the file system to the full size of the partition again

resize2fs /dev/wgkiste/home

e2fsck /dev/wgkiste/home