P4500 G2 - Node Removal from cluster

[SFP4500]

I have five (5) storage nodes running SAN IQ 9. Each node has 12x600GB 15K SAS configured in RAID-5. These five (5) nodes are operating in a cluster.

On the cluster, I have a total of 27TB of space (27,226GB). I have thin-provisioned 10 volumes of varying sizes from 100GB to 300GB with all of them utilizing Network RAID-5 (single parity). There are no snapshots configured anywhere.

Use summary says:

Storage Space:

Total: 27,226.89 GB

Provisioned: 692.62 GB

Available: 26,534 GB

Saved Space:

Thin Provisioning: 3,092.84 GB

Smartclone Feature: 0.00 GB

Total: 3,092.84 GB

Problem: I am trying to remove one of the nodes from the cluster (technically, I want to remove 2 of the nodes so that I have just a 3 node cluster). However, I am unable to do so. The CMC comes back and says:

"the cluster cannot be modified because some volumes have a Network RAID setting that cannot support the requested change. Change the Network RAID setting and try again".

I realize that by removing a node the cluster will restripe the volumes. OK with me.

Questions:

What do I need to do? There appears to be plenty of space available (i.e. I am not trying to cut the cluster's total available space to less than what we have.)

[Jitun]

I would suggest changing the volumes to Network RAID 10.

After the process of Restripe (if any) is complete, Remove the Nodes from the Cluster.

That should works.

You can change the Volumes back to Network RAID 5 after removal.

My personal Suggestion, leave the Volumes at Network RAID 10. Gives you the best protection and performance.