There are lots of good reasons for having spare disk for rootvg, as I
looked at in the post make
way for rootvg
. With virtual disks you can resize your volume group
on the fly:
If your rootvg “disk” is actually virtual,
such as a SAN LUN or a logical volume on the VIO server, then it usually
can be expanded on the SAN (or using extendlv on
the VIOS) and then recognised on the AIX LPAR using the -g flag
of the chvg
Note: this is supported for rootvg and concurrent vgs from AIX 6.1 TL 4. See IBM technote IZ80021 http://bit.ly/cmHjmy
Resizing the rootvg disk
I tried to increase rootvg on an LPAR running AIX 5.3 TL 11 and hit the following error:
# chvg -g rootvg
chvg: Re-sizing of the disks is not supported for
chvg: Unable to change volume group rootvg.
Looks like the volume group needed to be varied off and varied
on again. For rootvg, that means a reboot.
No reboot on AIX 6.1
In AIX 6.1 (from TL 4 - use oslevel -s to check your AIX level), you can increase rootvg on the fly.
chvg -g rootvg
chvg: Volume group rootvg changed. With
include up to 16 physical volumes with 2032 physical partitions each.
Sounds like yet another reason to migrate
to AIX 6.1