topic Re: Descrease filesystem size in Operating System - HP-UX

Descrease filesystem size

Bruno Bossier_1 — Tue, 19 Jul 2005 05:45:54 GMT

What is the correct procedure to online descrease the size of a filesystem ? I thought :

1. Defragment filesystem : fsadm -E /mountpoint
2. lvreduce ....
3. fsadm -b b /mountpoint

Bruno

Re: Descrease filesystem size

Pete Randall — Tue, 19 Jul 2005 05:49:34 GMT

Bruno,

If you shrink the container that holds the file system with lvreduce, you're going to lose data. If you do lvreduce (I can't remember) at all, it would have to be after the fsadm.

Pete

Re: Descrease filesystem size

Bruno Bossier_1 — Tue, 19 Jul 2005 05:51:38 GMT

OK, so I was wrong in the sequence :

1. fsadm -E /mountpoint
2. fsadm -b b /mountpoint
3. lvreduce ...

Correct ?

Re: Descrease filesystem size

Pete Randall — Tue, 19 Jul 2005 05:53:00 GMT

Bruno,

Also check this post:

http://forums2.itrc.hp.com/service/forums/questionanswer.do?threadId=582409

Pete

Re: Descrease filesystem size

Pete Randall — Tue, 19 Jul 2005 05:55:07 GMT

Bruno,

Yes, that's correct:

defrag
fsadm
lvreduce

Pete

Re: Descrease filesystem size

Robert-Jan Goossens — Tue, 19 Jul 2005 06:02:00 GMT

Bruno,

Be on the save side. Create a copy on tape or if you have enough filestore, create a online tar/cpio archive before reducing the volume.

The commands are correct, but the last time I preformed this I got a corrupt filesystem.

Regards,
Robert-Jan

Re: Descrease filesystem size

Bruno Bossier_1 — Tue, 19 Jul 2005 06:08:38 GMT

I know it's tricky and to be on the safe side, I should backup, delete, recreate and restore. It's for a sapdata filesystem, so even more tricky.

I just wanted to check. I'm not sure whether I would really do it.

Thanks for the answers !

Cheers,
Bruno

Re: Descrease filesystem size

Geoff Wild — Tue, 19 Jul 2005 06:14:50 GMT

I agree with Robert Jan - make sure your backups are working.

To be safe - I would reduce during your maintenance window - not during the day.

IE - during a backup - and to be safe - I would have SAP/Oracle down.

Rgds...Geoff

Re: Descrease filesystem size

Florian Heigl (new acc) — Tue, 19 Jul 2005 06:29:26 GMT

In general I have good experience with fsadm and reducing filesystems, but I haven't tried it more than 10 times, as it's plain forbidden @work.

You should definitely check the filesystem version and fsadm patch levels before the fsadm call.
root@xxxx:/tmp>fstyp -v /dev/vg00/rlvol15
vxfs
version: 4

if this doesn't print out Version 4 or 5, You might want to think twice on a sapdata filesystem.

florian

Re: Descrease filesystem size

Roland Piette — Wed, 20 Jul 2005 00:01:14 GMT

Hello Bruno,

If you decide to apply the procedure, don't do it with SAP running. Your DB will crash when reorganization is running !

Only a remark
Roland

Re: Descrease filesystem size

Matthew_50 — Wed, 20 Jul 2005 00:07:28 GMT

make a backup of your data before any changes

If you have OnlineJFS. do following steps.
1. fsadm -F vxfs -d -D -e -E /mountpoint
2. fsadm -F vxfs -b 4096000 /mountpoint
3. lvreduce -L 4096 /dev/vg00/lvol12

Note:
-b with new fs size in KB
-L with new fs size in MB

Re: Descrease filesystem size

Kevin Wright — Sat, 23 Jul 2005 16:09:29 GMT

If your FS is an even multiple of the extents, it may work. OnlineJFS, although advertised that is can resize, grow and reduce, rarely works correctly on a reduce. As other said, ensure your apps aren't running, and get a solid backup before attempting to reduce.

Re: Descrease filesystem size

Bill Hassell — Sat, 23 Jul 2005 21:16:43 GMT

You can safely assume that reducing a filesystem size will DESTROY data on your logical volume. Only if you are running 11.11 *AND* have purchased Online JFS version 3.3 *AND* the filesystem has been created or converted to version 4, will a reduction work. So in the majority of cases, your procedure will always be:

1. save all the files and directories (tape or another disk)

2. Un-mount the lvol

3. lvremove the lvol

4. Re-create the lvol in the size you want

5. newfs the lvol

6. mount the new filesystem

7. Restore your data

Re: Descrease filesystem size

Fabio Ettore — Sun, 24 Jul 2005 12:35:54 GMT

Hi Bruno,

with the Online JFS product you can shrink the filesystem even if the filesystem is mounted.

Anyway it is the best thing to backup all data before because it always is dangerous to shrink. I remeber something about the filesystem version, you should have the 3.3 or 4 version as Bill and Florian pointed out.

The good order is

fsadm -E /
fsadm -b /M /
lvreduce -L /dev/vgXX/lvolX

Best regards,
Fabio

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