In VMWare to share storage, using RDM disks as an example, we have to enable SCSI Bus Sharing.
According to documentation, if the storage will be shared within the same host (Cluster-In-A-Box) then the SCSI Bus Sharing mode should be Virtual. If the storage will be shared across different physical hosts (Cluster-Across-Box), then the SCSI Bus Sharing mode should be Physical.
All is well and good until someone wants to share storage BOTH within a box, AND across physical hosts. For instance, Guest A and Guest B are on Host 1 and Guest C is on Host 2. All Guests need to share the same storage. In this case, what mode of SCSI Bus Sharing do you use? Are there any other gotchas I'm missing?
I've tested this concept by creating two guests within the same physical host and connecting shared storage to a SCSI device that is in Physical mode. However, in this case, when trying to setup a Windows Server Cluster, it won't even allow me to proceed because there is a hard fail on the Persistent Reservations test. Alternatively, if I use Virtual mode for the SCSI Bus I get a warning on the Persistent Reservations test but can successfully build a clustered file server.
