Originally Posted by bakunin

In this case you will have to have a downtime of some sorts. Alas, there seems to be no way around that because you need to (newly) configure HACMP on your new system and this means some downtime when you make the transition. Fortunately this downtime can be minimised pretty much by good planning.

Furthermore you haven't said anything about involved OS and HACMP versions. I suppose you will have to update at least one of them (most probably both) too.

I'd investigate the following procedure (you might have to add some things, this is just a first idea):

- Take an mksyb from the running systems, create the appropriate LPARs on the new system and try to install it from the mksysb image without any data (just the rootvg).

- Now do all the updates (start with OS, then the HACMP software) on the new systems

- get a single LUN from your SAN and configure your new cluster with the same topology as the old one, just with one test-VG on the single LUN. Use this to test your zoning, (basic) cluster setup and other details.

- Finally, after preparing your new cluster with new addresses on the new hardware you need the downtime: get the SAN people to zone the old data-LUNs to your new hardware so that the disks are seen from your cluster nodes, create the new cluster config for the imported VGs and start. You might want to add the DNS names of the old cluster service IPs as aliases to the new addresses so that the transition becomes smoother for the clients.

I hope this helps.

bakunin