SAN Volume Controller / Storwize / Flash System version 8.4.2 allows you to non-disruptively migrate a LUN between array controller clusters. It’s set up like remote copy, except you can map the remote copy to the same host at the same time. The remote copy becomes non-preferred paths for the same vdisk and vdisk ID. Then you can switch who is primary. Then you can remove the old copy.
Here is someone who did a demo video: https://www.youtube.com/watch?v=NpcOoshkm4w
When you replace a drive on one of these, mdisk arrays do not auto-rebuild.
If the GUI fix procedures go away, or never show up, or whatever causes the replacement drive to not get included as a new drive in the mdisk, you can do this manually.
First, look for the candidate or spare drive you want to use.
lsdrive | grep -v member
Then, make sure that drive ID is a candidate:
chdrive -use candidate 72
Then, find the missing member:
lsarraymember mdisk1 | grep -v exact
Then, set the new drive to use that missing member ID:
charraymember -member 31 -newdrive 72 mdisk1
You can watch the progress of the rebuild:
lsarraymemberprogress mdisk1
