Swapping two boxes: L3000 and N4000

[Filipe_1]

Folks,

We have two HP-UX 11.11 boxes, a L3000 and N4000. Both have similar applications and databases.

Our user decided the things would be better if we "swap" both machines, that is, both hosts must change hardwares.

We wonder the most reliable way to achieve that. We decided that we may do as the following:

- Perform make recoveries from both boxes, lets say L and N.
- Switch HBAs (doing so, no zonnning and/or mapping will be required).
- Install the make recovery from the N on the L.
- Check if things are OK.
- Install the N´s make recovery in the L.
- Voilá!

What we think that could complicate our perfect world:

- Both servers have two HBAs accessisng EMC storage using full load-balance/failover. We are not sure if it keeps working on anther harware since it is licensed.

- The L has Mirrordisk mirroring boot disks. The N haven´t.

Our biggest concern is about harware compatibility. Are the hardwares compatible enough to make the OK from one work on another hardware?

Is there something more we must concern about? What do you think that could go wrong? Have we forgot something?

Unfortunately changing boot disks is not a option.

Both servers are full patched.

Thanks in advance, and will assign points,

Filipe.

[Steven E. Protter]

Shalom Filipe,

This is going to be very,very hard.

The L and N class are two totally different designs.

That being said, you have a few possibilities:

1) make_tape_recovery tape. If you have two tapes the same format, shut down all applications and databases and do a backup of both systems complete. Then try a tape boot in reverse pressing a key for manual intervention so you can deal with the different LVM configuration of the two boxes.

2) make_net_recovery Same basic idea, no need to deal with tape formats.

3) Ignite Golden Image: less hardware dependent, but more chances to fail.

The hardware issues are going to make this most complex. I state frankly that I would not like to be involved in this situation.

You are much better off bringing in a third box and building the new system clean and rotating it into production use.

The hardware is where the risk is as you note and that is where things are going to get hairy.

SEP

[Pete Randall · Accepted solution]

Filipe,

Compatibility is probably going to be OK. Any mirroring will have to be re-established after the restores. I would think that your EMC storage would be fine since both systems already access it. Do a "vgexport -s -m" on both systems prior to backing them up and save the mapfiles so you can then re-create the device files and vgimport:

mkdir /dev/vg01
mknod /dev/vg01/group c64 0x010000
vgimport -s -m /tmp/vg01map /dev/vg01
vgchange -a y /dev/vg01


Pete

[Devender Khatana]

Hi,

There should not be a compatibility problem here. Insure latest Ignite version to be installed on both servers before taking ignite backup. Also use -I option in make_tape_recovery for interactive recovery while recovering. To be safe I would go for using one of the mirroed disk of L Class to test restore and use a spare disk for testing restore on N-Class. ( Will keep one of the current boot disks of both servers handy for quick rollback if not successful)

Also before taking ignite backups if possible vexport the VGs so that the mapfiles are also backed up. Otherwise back these seperately to convenient location.

Importantly also collect running configuration for both the server through something like nickel for reference in worst case if required.

HTH,
Devender

[Pete Randall]

Just a clarification on SEP's comments. He must be thinking of different boxes because the L and N were, in fact, very similar.


Pete

[Filipe_1]

Devender,

If I got this straight, I assume that I can do as the following:

- make_tape_recovery of the N.
- make_tape_recovery of the L.
- break boot disk mirrored the N.
- Use the released disk of the N for intalling make_recovery from the L (I interactively choose this disk at the install time)
- Boot this disk.

If some unsolvable problem occurs, I can boot from the original disk.

Is this OK??

[Pete Randall]

Filipe,

That's perfect.


Pete

[Devender Khatana]

Hi,

Yes it is perfect.

-Devender

[Filipe_1]

Thanks, gentlemen.

[Steven E. Protter]

Actually,

I was under the impression that the N box line was substantially different from all other HP-9000 boxes because the N box and its design came to HP via an aquisition.

My memory could be faulty, but I recall reading that here in the forums.

I'm insterested to see if it works.

Assuming I'm wrong in my basic assumption the basic plan looks great.

SEP