topic Re: lvreduce in Operating System - HP-UX

lvreduce

Keely Jackson — Fri, 14 Jun 2002 13:50:22 GMT

Hi

I have just increased in size the wrong logical volume. Stupid or what - don't answer that. Anyway, having read other threads on this, I gather in general that using lvreduce is not a good idea. However, as I have only just increased the lv and nothing is likely to have used the space, am I ok to reduce it or not? I have on-line jfs and os is 10.20

Thanks
Keely

Re: lvreduce

Pete Randall — Fri, 14 Jun 2002 13:55:59 GMT

Hi Keely,

You should be safe in this case.

Pete

Re: lvreduce

Sandip Ghosh — Fri, 14 Jun 2002 13:57:03 GMT

If you are sure that ng has been written on the disk after you have increased the lv, you can take a chance to reduce the lv. But be careful don't reduce more than whatever you have increased. It may require a fsck.

Sandip

Re: lvreduce

James R. Ferguson — Fri, 14 Jun 2002 13:59:56 GMT

Hi Keely:

If you have done an 'lvextend' but nothing more (i.e. no 'fsdm'), you have not affected the filesystem; only the container in which it sits. In this case, you can safely 'lvreduce' to your *exact* original size.

For insurance, of course, make a backup first!

Regards!

...JRF...

Re: lvreduce

Sanjay_6 — Fri, 14 Jun 2002 14:02:25 GMT

Hi Keely,

Take a backup, just in case. The n try a lvreduce.

But it is not such a good idea. you should be doing an lvremove and then recreate the lv.

Hope this helps.

Regds

Re: lvreduce

Helen French — Fri, 14 Jun 2002 14:02:43 GMT

I would do a backup first. You will be able to reduce the LV without issues, if you haven't done anything after lvextend. While reducing it, clearly specify the original space. Check the FS with 'fsck' command, once everything is set right.

2 cents ..

Re: lvreduce

Victor_5 — Fri, 14 Jun 2002 14:03:22 GMT

Yes, in your case, you can use lvreduce safely, good luck!

Re: lvreduce

Martin Johnson — Mon, 17 Jun 2002 13:46:37 GMT

Do a backup just in case! It better to be safe than sorry.

Marty

Re: lvreduce

Bill McNAMARA_1 — Mon, 17 Jun 2002 14:15:18 GMT

In all of the cases I've tested on, lvreduce is okay ONCE you defrag first (with fsadm). Apart from the obvious (don't defrag first) The only time I've seen trouble was when a failing CPU started screwing things up (on the defrag).

However, if you haven't modified your filesystem (in any way) the space should still be unused.

As the others suggest, backup, a quick tar to tape is always good to have.

Later,
Bill

Re: lvreduce

Jim Turner — Mon, 17 Jun 2002 14:31:16 GMT

Hi Keely,

I agree with Pete, Jim, et. al. As long as you have NOT extended the filesystem and have only just extended the LV, you can lvreduce back to the original size with no damage. I have done this successfully.

Cheers,
Jim

Re: lvreduce

MANOJ SRIVASTAVA — Mon, 17 Jun 2002 14:55:11 GMT

Hi Keely

If you have just meaning like ( no reboots , file deletes and file creation on the lvol ) then you can safely reduce it.

Manoj Srivastava

Re: lvreduce

Juan Manuel López — Mon, 17 Jun 2002 15:11:34 GMT

I think is very important have a tape make_recovery done.
On case to use lvreduce, do not forget use newfs command to create a ew fs with the new lv size properties.

If you wants the commands or more information, ask me.

Juanma.