VMware Virtual Machine Clustered Filesystem Setup

Solution 1:

Note: I've never done this before.

The shared storage RDM should be possible, although having five nodes accessing it could introduce hilarity.

The technique you want is similar to how two node Microsoft Clustering Services is implemented (with a shared quorum drive); VMware provide a documented method for how to achieve it.

The solution looks well documented, if a little hairy. I'd recommend building and testing it in a lab before considering letting it anywhere near your production cluster.

Good luck.

Solution 2:

I was going to suggest iSCSI but no matter how you slice it, you need to create a LUN to share between the VMs regardless of the protocol (FC, iSCSI) used. You mention a LUN limit, but you shouldn't need to create more than a single LUN for all the VMs to share. Each would have an RDM pointing to that LUN. Are you saying you lack the ability to create a single additional LUN on your SAN?