I've successfully upgraded to AIX 5.1 today, but as a result, /usr is now
quickly approaching its size limits. The former sysadmins have left me
with a rather unfortunate rootvg layout, on the only disk available, so
I can't extendvg to other disks. I'd like to chip a gigabyte off my much
too luxurious /home and let /usr grow into that, but how do I shrink /home
first? Backup to tape --> boot from CD --> shrink filesystem --> restore
backup would probably work, but the last backup I restored from tape took
something like six hours to finish, and I'd much rather do this a little
quicker. Please?

Ulrich Plate

You only need to backup /home (e.g., with tar), then umount
and remove /home, re-create it smaller, and restore.

If you have enough disk space on another filesystem, you can
do your backup on a file.

E.g: (if you have space in /opt)
umount /home
OBS: If it does not work, try
df /home
fuser /dev/hd? (replace ? by the displayed value)
=> control/kill the using processes
umount /home (should success then)
mount -r /home (mount it as read-only)
tar cf /opt/home.tar /home
umount /home
rmfs -r /home
smit
=> To re-create the lv with the same name, and add the jfs
mount /home
tar xpf /opt/home.tar

This will be MUCH quicker than using tapes.
Regards,
Stephane

Ulrich Plate a écrit:
>
> I've successfully upgraded to AIX 5.1 today, but as a result, /usr is now
> quickly approaching its size limits. The former sysadmins have left me
> with a rather unfortunate rootvg layout, on the only disk available, so
> I can't extendvg to other disks. I'd like to chip a gigabyte off my much
> too luxurious /home and let /usr grow into that, but how do I shrink /home
> first? Backup to tape --> boot from CD --> shrink filesystem --> restore
> backup would probably work, but the last backup I restored from tape took
> something like six hours to finish, and I'd much rather do this a little
> quicker. Please?
>
> Ulrich Plate

Ulrich Plate <plate@gSPAM_ME_NEVERol.com> wrote in message news:<pan.2004.05.22.14.32.36.963450@gSPAM_ME_NEVE Rol.com>...
> I've successfully upgraded to AIX 5.1 today, but as a result, /usr is now
> quickly approaching its size limits. The former sysadmins have left me
> with a rather unfortunate rootvg layout, on the only disk available, so
> I can't extendvg to other disks. I'd like to chip a gigabyte off my much
> too luxurious /home and let /usr grow into that, but how do I shrink /home
> first? Backup to tape --> boot from CD --> shrink filesystem --> restore
> backup would probably work, but the last backup I restored from tape took
> something like six hours to finish, and I'd much rather do this a little
> quicker. Please?
>
> Ulrich Plate

mksysb to tape and restore from that mksysb with the shrink
filesystems option. How big is rootvg ? 6 hours is a very long time,
longest I've seen it take is about an hour.

Steve

Stephane Gassies wrote:

> You only need to backup /home (e.g., with tar), then umount and remove
> /home, re-create it smaller, and restore.

Splendid! And thanks a lot for your step-by-step explanation, you made it
almost too easy... Took me a minute to figure out how to create a
filesystem, a mount point and a logical volume all in one swift move, but
it was indeed a little quicker than tapes.

Thanks again
Ulrich Plate

Ulrich Plate <plate@gSPAM_ME_NEVERol.com> wrote in message news:<pan.2004.05.22.22.32.31.870490@gSPAM_ME_NEVE Rol.com>...
> Stephane Gassies wrote:
>
> > You only need to backup /home (e.g., with tar), then umount and remove
> > /home, re-create it smaller, and restore.
>
> Splendid! And thanks a lot for your step-by-step explanation, you made it
> almost too easy... Took me a minute to figure out how to create a
> filesystem, a mount point and a logical volume all in one swift move, but
> it was indeed a little quicker than tapes.
>
> Thanks again
> Ulrich Plate

Be very careful when doing this - the rootvg filesystems are created
with some special options. NBPI, AGsize, etc.

Also - FWIW - AIX 5.3 will support a 'chfs -a size=-' option to
decrease filesystem sizes.

BV

Bill wrote:

> Also - FWIW - AIX 5.3 will support a 'chfs -a size=-' option to
> decrease filesystem sizes.

Well, not on my senile 7043-140, I'm afraid. 5.1 is the last AIX version
supported on that hardware. I'll be cleaning out some things next, one of
the former admins seems to have installed a whole suite of GNU tools in
some rather obscure /home/local/opt/whatnot and /usr/don't/ask
directories, some of the tools even more than once. Looks like I can get
rid of almost a gigabyte worth of cruft...

Ulrich Plate