====== Uncommon system administration tricks ======

===== Spurious error about no free space / Can't create new files =====

(Even though ''df'' does show free space).
Most obvious cause is lack of free inodes.

Use ''$ df -i'' to see the amount of free inodes.
Each file takes one so if there's none free files will have to be deleted. Temporary directories, caches (''~/.cache'', ''~/.thumbnails'') and trash are good starting places.

===== LVM volume groups with the same name =====

Volume groups with the same name can't coexist. When a disk is enabled containing the same volume group as an already active group an error like this will be shown upong running ''vgscan'':

<code>WARNING: Duplicate VG name vg0: Existing abcD1e-fgHi-jklM-NOpQ-RSt2-UVwx-34YzAB (created here) takes precedence over BAzyxW-vU4T-S3rq-ponM-LkJI-hG2f-Edcb1a</code>

Some of the ''vg*'' tools can take a volume group ID too, e.g. to rename the second group:

<code># vgrename BAzyxW-vU4T-S3rq-ponM-LkJI-hG2f-Edcb1a vg0_alt</code>

References:
https://bugzilla.redhat.com/show_bug.cgi?id=147361