I've come across a possible problem with 2 SQL MSCS 2003 clusters that were converted to VMs running on ESXi 4.0 with HP P4000 SAN. Basically one node was evicted from each cluster pre-conversion to leave us with two single node clusters. These were then converted straight (by a contractor), just as if regular servers as far as I can tell but they have worked fine as single node clusters (clustered disks are just vmdk files on a LUN).
During a support call recently a VMWare engineer pointed out settings on the clusters that he said were wrong. He provided a document that I have now gone through and I can find multiple inconsistencies on our clusters when compared to the supported configurations in VMWare's document (http://www.vmware.com/pdf/vsphere4/r40_u1/vsp_40_u1_mscs.pdf
). These include the alarming fact that apparently our SAN is not supported in any MSCS setup as it is iSCSI. The servers have thin provisioned disks, SCSI bus sharing set to None, only one SCSI controller and Memory Overcommit enabled.
Can anyone comment on whether all of the above settings (including lack of support for iSCSI SANs) still apply in a single node MSCS cluster situation? As you still have a quorum and are still reliant on the Cluster service I would presume the restrictions still apply but haven't found anything that confirms either way.
Does anyone also know whether there is any MSCS configuration that would allow snapshots? The reason for the original support call to VMWare was that the clusters were snapshotted (though failed) by Backup Exec after the selection list was changed in error. It basically killed the clusters and we had to build fresh VMs and restore C and System State from backup and then reattach the clustered disks. I’d love to know why exactly the snapshot operation killed the clusters rather than just failing - if anyone can shed any light on that I’d be really grateful.
Thanks in advance for any advice.