Swapping L3K and N4K, the sequel: the hardest way

[Filipe_1]

Hi Folks,

This is somewhat a sequel of this thread:
http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=979159

That said, let me go to my B plan, with a little help of my friends at ITRC.

The fact is that I have to outline a strategy to swap both hardwares, and, of course, can’t rely on make_recoveries at this point. Too bad. Both are in production, but one I can manage to stop a few days (the N4K, the one that will act as the L3K someday).

Main Idea:

- Stop the N4K in, say, Wednesday. Save its configurations, of course. Prepare the OS to act as the L3K, that will be in full production at this period.
- Prepare it till Saturday morning, when I shut down the L3K. Keep the L3K stand-by and untouched in case of rollback.
- Let N4K work as L3K till next Wednesday.
- If client gives thumbs-up, we wake the L3K configuring it to act as the old N4K.
- Happy ending (wishful thinking, of course)

Some guidelines:

- There is a tiny chance that I could have a third box to help manage this mess, with less risk and downtimes. As a matter of fact, I cannot count too much on this.
- I am not sure how can I prepare an already installed box to act as another, even if it will eventually receive other machine’s HBAs (and the disks, of course). Should I reinstall it?
- The present L3K is a critical production box. I need to do all the planning it needs, since the first try failed.


The OS configurations of both machines are pretty similar in terms of:

- Users, groups, permissions, etc;
- Security pocilies (yes, both are in trusted mode)
- Storage (EMC DMX2K) and PowerPath
- Patch level
- Applications
- Etc.

Anyone can point to any document/procedure/script/whatever that can guide us to perform this swap? Any hints and advice?

Thanks a lot, will give feedback.

Filipe.

[Steven E. Protter · Accepted solution]

Shalom Filipe,

This is a disaster waiting for you to make it happen. There are so many pitfalls I can't even begin to count.

I mirror my earlier recommendation. Don't do it. Lease some hardware and take your time with the migration.

If you must do, it have a nice stack of tapes and make Ignite backups as you move through the process.

What you are doing is not in any document I know of. If you pull this off and end up with two working systems, YOU should write a paper.

I think Ignite Golden Images is the best way to attempt this. Image both machines. Store the image on an Ignite server which need not be very powerful, just have lots of disks. Then try and Ignite the machines off each others .gz file.

This may work if you do not wish to do an OS upgrade. Ignite has an interface to allow you to intervene and re-arrange the disk/SAN etc.

SEP

[Filipe_1]

Steven,

I have already configured Solaris box that way. In that OS you have something called "unconfigure" that cleans pretty much everything that needs to be changed when you have to reconfigure a working system. Even changing the hostname, IP addresses, Veritas garbage etc. by hand is not that hard. The problem is doing it with HP-UX and even worse, in trusted mode.

If reconfiguring a working system to act as another, other hostname, IPs and so forth is too hard, what about cold installing? I think is not that difficult to copy some configurations between both boxes, the problem here is that I am not very sure about everything that needs to be changed or even if there is something out there that can make this endeavor easier.

Both systems are 11.11

Cheers,

Filipe.