root disk migration

[Paul Wahner]

Hello,

I inherited two K210 servers running 10.20. The root disks (vg00) on these are spread out among two 2GB physical volumes.

Is there a relatively painless way to copy the contents of these two disks onto one 4GB disk?

Thanks,
Paul Wahner

[eran maor · Accepted solution]

Hi

my advise is to do a ignite backup with make_recovery to a tape ( the make_recovery will backup all the vg00 )

after that to boot with the cassete and restore all the data into the new disk .

i dont think that there is an another easy way to do it .

[James R. Ferguson]

Hi Paul:

You could try using 'pvmove' but since you are dealing with vg00 and the requirement for at least some of the filesystems to be contiguous, you probably won't find this approach simple, or certainly a one-step process.

Take a look at the '-n' option of 'pvmove' if you wish. This allows moving extents based on logical volume and could prove helpful in constructing a strategy depending upon how each logical volume is laid out.

Personally, I would probably resort to Ignite using 'make_tape_recovery' and simply reinstall onto a single physical disk.

Regards!

...JRF...

[Patrick Wallek]

Paul,

You've got a couple of options here:

1) Download and install HPs Ignite/UX product ( http://software.hp.com/products/IUX ), do a make_tape_recovery of your VG00 and then boot from that tape and re-install on your 4GB drive. I have done this in the past and it worked well. I went from a VG00 of 8 x 2GB drives to 2 x 18GB drives and it worked like a champ. The command to use to create the tape is:

/opt/ignite/bin/make_tape_recovery -a /dev/rmt/0mn -I -v -x inc_entire=vgboot

Just make sure you put the appropriate tape device name where I have /dev/rmt/0mn above and be sure to use the no-rewind tape device.

2) Have a look at the following thread, and specifically Peggy Fongs response in that thread. She outline a process that does NOT use Ignite that makes a copy of VG00 to another disk. I don't know if it will work since your VG00 is spread over 2 disks, but I think it might.

http://forums.itrc.hp.com/cm/QuestionAnswer/1,1150,0xa1c6d06ed8c8d4118fef0090279cd0f9,00.html

Hope all this helps you.

[Emil Velez]

I agree with the ignite solutions and would create a ignite tape anyway before doing any hard core LVM maintenance. I will suggest a
summary of the major steps. Please do not try this without planning and reviewing the steps with your specific device files. You will need to review man pages on pvcreate, mkboot,pvmove and lvlnboot at a minimum but it is possible.

1. pvcreate -B
mkboot
mkboot -a of your new disk

2. vgextend (add disk to volume group)
3. pvmove all LV to other disk.
You must do this in order with /stand swap, /
first and then the other logical volumes

4. make sure BDRA is correct

lvlnboot -v

5. edit /stand/bootconf

6. You should then be able to vgreduce the old
disks out of the volume group.

I have done this procedure many times and it must be carefully planned and done and if one step is missed your system can be rendered unbootable. (Is that a warning enough)..

Good luck

[Thierry Poels_1]

Hey guys,
how about the easy way: through mirroring ?!?
This can be done online (maybe just a shutdown to attach the drive physically) and with little risk. Simply add the 4GB drive to VG00, make it bootable, mirror all lvols to this drive, and remove the 2GB disks from VG00.
(little hint: try to boot from the 4GB disk before you remove it from VG00)

"Just" two requirements:
- you need Mirror/UX software
- Max PE per VG of VG00 has to be large enough to hold a 4GB disk (should be!)

good luck,
Thierry.