Extending root logical volume

[Joe Profaizer]

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

[Vincenzo Restuccia]

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

[Joe Profaizer]

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

Are there any other methods?

Thanks,

.Joe

[Patrick Wallek]

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.

[Victor BERRIDGE]

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

[boley janowski]

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

this link might help.

[Wieslaw Krajewski]

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.

[Wieslaw Krajewski]

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.

[Joe Profaizer]

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

..Joe

[Wieslaw Krajewski]

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.

[Wieslaw Krajewski]

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.