Until I really began to explore the practical implications of using ZFS with VCS, I would not have necessarily realised the obstacles that would be put in my path. Data integrity is a must-have for storage in a shared host environment, so it surprised me to learn as I opened this particular Pandora's box that VCS provides no solution at all for ensuring data integrity on any of the ZFS pools that are a part of your cluster. The 'Zpool' agent is dumb. It imports the pool. It exports the pool. "What about SCSI-3 persistent reservations?", I hear you ask. What about them, indeed. ZFS is a competing product, I won't expect an answer to that problem coming from the Symantec camp. So I took up the gauntlet on a mission to add SCSI-3 PR support to the Zpool agent for my client. I succeeded. So I have written up some notes that might help direct others should they stumble across the same obstacles, and along the way I've discovered the benefits that Solaris MPxIO has to offer that are superior to VxDMP.
Technical Prose: SCSI-3 PR with ZFS on Veritas Cluster Server