Splitting multisite cluster

[dgutschow]

We have a 10 node multisite cluster. We would like to split the cluster into 2 - 5 node sites. It looks to be possible from the documentation to just remove the second set of 5 nodes from the multisite cluster and bring them up as their own site, but I am not sure. Has anyone done this, and if so, what are the "gotchas" to worry about? Thanks in advance.

David

[oikjn]

are you keeping it as a single cluster?  If so, its as simple as just creating another site in CMC and changing the location on the VSAs to the new site.  CMC will automatically convert it to a multi-site cluster and there would be no downtime required.  It will most likely force a restripe of the cluster so that it preserves the rules of your network raid level so that you don't have both copies of a data set on only one site.

I've switched a cluster from single to multi and back a few times without issue.  I most recently did it because I had four VSAs hosted on three computers and wanted to make sure I didn't have an availability problem if the host with the two VSAs on it went down....  it worked exactly as expected and I was able to revert back once I got the missing host back up again.

[dgutschow]

We are actually trying to make it into two separate 5 node clusters with no connection to each other. My concern is that currently we have it set up as a multi-site cluster which has one set of 5 nodes as the secondary for the other set of 5 nodes. What will happen when we remove that secondary cluster of 5 and make the primary only a set of 5 nodes by itself. I am fairly sure it should be fine but wanted to get others input. Thanks for the info.

[oikjn]

it depends on what your network raid level is set for.  If you only had raid10, then you will have to sacrofice cluster storage size or drop to raid0 (probably not doable).  You are effectively removing the five nodes from the cluster, so you should calculate if you have enough storage space if you lose those nodes and then do the node edit to remove all five at once so it doesn't do five re-strips!  It will probably take a long time for the migration to complete, but after that is done, you can remove those nodes from the mgt. group and create another group.

btw, having to seporate mgt. groups is definitely better if the data is async for DR since this will make sure you are really independent of the primary.