install with a root mirror

[Torsten.]

Elmar, this sounds reasonable.

I was trying to disable a disk that way, changed anything and reboot, then the disk was synced. I agree we have new IDs after a new installation, but not after an upgrade, right?

[Kanagaraj]

//Booting from Disk B gives me errors about missing Disk A. (The disk is still in place and operational.)//

you try boot from Disk B as follows.

stop the booting at ISL>

boot by diskB--> ISL>bo -lq

Problem:
Disk A is present but it doesn't have LVM structure of 11.11 (previous OS)..Now DiskA has new OS 11.23.So DiskB has mirrored info,So quorum will not alow to boot from diskB,this case DiskB should be boot by disable quorum.(bo diskB -lq)

[Elmar P. Kolkman]

You get new ID's when the volume group is been re-created... For instance a new install.
It's the same as when you re-install a system with ignite: you also have to re-add the second disk and mirror everything to reinstate the mirrored vg00.

[Chris Howard]

Booting from Disk B, either with or without the '-lq' seems to work ok. I think with '-lq' it is happier during bootup.

After bootup I only get error messages when I run something like 'vgdisplay -v /dev/vg00'.

So I think either way works ok.

It would be really nice to have a more direct split, something like 'lvsplit' to let me peel off everything on that second drive. But I have not found anything like that yet.

I think I have enough to go forward with.
Thanks to everyone.