topic Re: Extending root logical volume in Operating System - HP-UX

Extending root logical volume

Joe Profaizer — Mon, 14 May 2001 16:31:57 GMT

I have plenty of available space in my vg, but when I try to extend my 140mb root to 252mb, I receive an error message stating that there's not enough physical extents available. Failure possibly could be do to contiguous allocation policy or strict allocation policy.

Please advise on how I can extend. I have a feeling it may be the "contiguous" policy.

Thanks,

..Joe

Re: Extending root logical volume

Vincenzo Restuccia — Mon, 14 May 2001 16:36:53 GMT

root is contiguous with swap and stand.You can extend it with Ignite-UX (make_recovery).

Re: Extending root logical volume

Joe Profaizer — Mon, 14 May 2001 16:51:03 GMT

So -- create a make_recovery tape, then boot off of the tape and extend root?

Are there any other methods?

Thanks,

.Joe

Re: Extending root logical volume

Patrick Wallek — Mon, 14 May 2001 16:54:58 GMT

If that is your only root disk, then Ignite/UX and a make_tape_recovery tape is your only option.

If you have more than 1 disk you can use, then Peggy Fong has posted a very effective dd method that you should be able to use. I'll see if I can find it for you.

Re: Extending root logical volume

Victor BERRIDGE — Mon, 14 May 2001 16:57:01 GMT

Hi Joe,
There is no other alternative to make_recovery since it needs to allocate contiguous space, but anyway 140Mb for root should be plenty enough IMHO, but well if thats what you want, go ahead and at the same time extend /stand since it also has to be on contiguous allocation, this will let you save more kernels for backups...

All the best

Victor

Re: Extending root logical volume

boley janowski — Mon, 14 May 2001 17:36:47 GMT

http://forums.itrc.hp.com/cm/QuestionAnswer/1,1150,0x5c9eee3e323bd5118fef0090279cd0f9,00.html

this link might help.

Re: Extending root logical volume

Peggy Fong — Mon, 14 May 2001 18:01:26 GMT

Re: Extending root logical volume

Wieslaw Krajewski — Mon, 14 May 2001 19:12:18 GMT

Hi,

I agree with Patrick that in the case of only one disk in
vg00, Ignite and make_recovery is only possibility.
If however you have extra spare disk you can add to vg00 there is efficient and fast way of extending root fs.
I tried it in the past in HPUX9 and HPUX10. It can be briefly stated as follows (assuming that we want to extend lvol3 which contains root file system):

1. pvcreate /dev/rdsk/cCtTdD

where /dev/dsk/cCtTdD is new added disk

2. vgextend vg00 /dev/dsk/cCtTdD

3. pvmove -n /dev/vg00/lvol4 /dev/dsk/cXtYdZ /dev/dsk/cCtTdD

where /dev/dsk/cXtYdZ is the disk in vg00 used normally.

4. pvmove -n /dev/vg00/lvol5 /dev/dsk/cXtYdZ /dev/dsk/cCtTdD

if necessary, i.e. more free extents needed.

5. lvextend -L new_size_in_MB /dev/vg00/lvol3

now it is possible in contiguous way

6. pvmove -n /dev/vg00/lvol4 /dev/dsk/cCtTdD /dev/dsk/cXtYdZ

pvmove -n /dev/vg00/lvol5 dev/dsk/cCtTdD /dev/dsk/cXtYdZ

7 vgreduce vg00 dev/dsk/cCtTdD

to free added extra disk.

Other variants are possible too.

Hope this helps.

Rgds.

Re: Extending root logical volume

Wieslaw Krajewski — Mon, 14 May 2001 19:21:54 GMT

Hi again,

I've forgotten to add that last month (do not remember the date) the problem of extending root file system was
discussed. I'd like to mentioned what Bill Hassel stated that extending root fs in fact not neccessary, and should be avoided. Personally I share his opinion.

Rgds.

Re: Extending root logical volume

Joe Profaizer — Mon, 14 May 2001 19:26:43 GMT

My root volume is mirrored. Can I split the mirror, then proceed?

..Joe

Re: Extending root logical volume

Wieslaw Krajewski — Mon, 14 May 2001 20:54:40 GMT

Hi,

You should not spli. But you can

lvreduce -m 0 /dev/vg00/lvolX

to remove mirroring and after the whole procedure

lvextend -m 1 /dev/vg00/lvolX

to recreate mirrored copies.

So for the time of doing all these reconfigurations you have no mirroring, but it last for a while.

Rgds.

Re: Extending root logical volume

Wieslaw Krajewski — Mon, 14 May 2001 21:13:56 GMT

Hi,

I am afraid that I did not read your last question carefully.
You have lvol3 mirrored.
So you do not need neither split not lvreduce lvol3.
Instead you should free physical extents on both disks, i.e. extents belonging to lvol4, assuming that lvol4 is mirrored too. In such case you should split lvol4 and pvmove lvol4 and lvol4b.

Hope this brief explanation helps.

Rgds.