topic Re: Boot disk copy in Operating System - HP-UX

Boot disk copy

Jorge Prado_1 — Mon, 12 Jul 2004 12:05:47 GMT

Hello,
As I can copy the boot disk whit MirrorDisk/UX and then to split it?.
( Alone I need to have a copy of this disk. Not synchronize permanently )

Thank in advance

Atte.

Jorge Prado

Re: Boot disk copy

Tom Maloy — Mon, 12 Jul 2004 12:09:11 GMT

You can use dd, referencing the raw disk devices:

dd if=/dev/rdsk/c1t6d0s2 of=/dev/rdsk/c1t5d0s2 bs=27125760

where "if" references the source disk, and "of" references the disk copy to be created.

Re: Boot disk copy

Geoff Wild — Mon, 12 Jul 2004 12:24:51 GMT

Are you using MirrorDisk/UX?

If yes, then create a 3rd mirror - then split it whenever you like - say once a week or daily....then re-sync whenever you need to...

Rgds...Geoff

Re: Boot disk copy

Victor BERRIDGE — Mon, 12 Jul 2004 12:45:41 GMT

Hi Jorge,
What are you trying to do?
As mentionned if you have mirror-ux you can mirror a complete disk and use lvsplit to split all the logical volumes... and then lvmerge to merge to resync...
But this is not intended for long term splitting... which would mean you dont really to mirror because all you want is a regular copy...
A copy of two identical disk using dd as also already mentionned would do just the job: No need of extra software if you dont have mirror-ux. if done using the raw devices, it will be bootable etc...

All the best
Victor

Re: Boot disk copy

Sundar_7 — Mon, 12 Jul 2004 12:57:42 GMT

Hi Jorge,

I understand you would like a static copy of the boot disk with MirrorUX/DX.

You can create a mirror using lvextend -m option and then split the mirror using lvsplit command - this way u will have a static copy of the boot disk.

But remember, Mirrorux/dx will not mirror the boot LIF volumes. So if you want to be able to boot from the mirror copy then you have execute mkboot commands.

Also make sure you use -B option with pvcreate for the mirror disk.

-- Sundar.

Re: Boot disk copy

Sridhar Bhaskarla — Mon, 12 Jul 2004 17:16:30 GMT

Hi Jorge,

You can do the mirroring but splitting will be a problem as it will split the logical volumes but not the disks. You cannot reduce the disk without reducing the logical volumes on it so that disk may not work. You can remove the mirror online (if it supports hot-pluggability) and replace it with a new one and run the usual 'mirror restore' process but you will have to fix the taken out disk booting in LV maintenance mode as it would be hardcoded with the device file names.

Safe and headache-free way is to use make_tape_recovery tape. Take the image of the original server and put it on the other one if your intention is to clone the systems.

-Sri

Re: Boot disk copy

Jorge Prado_1 — Tue, 13 Jul 2004 09:46:16 GMT

Thanks to all for their suggestions, will review all to them.
I am going to specify with but details: Operating system: HP-UX 11i
Server: rp5470
Mirrordisk/UX
Two internal discs.
They are needed to make changes in the configuration of general software (Oracle IAS), but saving and maintaining a copy of the booteable disk and its applications (Oracle and ias) in the second disk to make a fast return back in case are not the changes.
Which is the best method?
Can be used Mirrordisk for this?

Tkank in advance

Jorge Prado T.

Re: Boot disk copy

Victor BERRIDGE — Tue, 13 Jul 2004 09:59:42 GMT

In this case, well yes, use of mirror/ux is adequate
I understand as:
You are always in a mirror configuration but
use the split (as I would when it comes to install patches...) for upgrade or testing...

All the best
Victor

Re: Boot disk copy

Sridhar Bhaskarla — Tue, 13 Jul 2004 10:13:06 GMT

Hi Jorge,

In this case, split/merge will work. This would be the scenario.

1. You will have mirrors all the time.
2. Before you do the change, split the mirrors.
3. Make changes. Let the system run with the changes for a day or two.
4. If everything is fine, then merge the mirrors back to go back to step 1. If you have to back out, boot from the split mirror and re-establish the mirroring.

Merging mirror is easy. But if you have to boot from the split mirror in any unwanted situation, then the process can be confusing. There have been many threads on booting from the split mirror. Search the forums for all these procedures or let us know and one will post the procedure. In any case, keep a couple of make_tape_recovery tapes handy. They can save you from trouble.

-Sri