On May 7th 2012, DataCore Software released a plug-in for SANSymphony-V and VMware vSphere 4.1 and 5.0 and greater. The plug-in adds a SANSymphony-V tab to your VMware vSphere Client. This allows for integration between SANSymphony-V and VMware. From the tab within the vSphere Client you can perform the following operations:
- Create virtual disks and present storage
- Unpresent and delete virtual disks
- Perform a snapshot
- Schedule snapshots and retention
- Perform a snapshot restore
One of the more interesting functions is the snapshot restore. I asked DataCore about the scenario where you have multiple virtual machines per LUN or virtual disk. You cannot just revert the snapshot or you would restore every VM on that LUN. The interface allows a user to granularly restore a VM on a LUN shared with multiple VMs. The DataCore plug-in accomplishes the restore by performing the following operations:
- The user selects the LUN/Virtual Disk and individual VM they want to restore
- DataCore presents the snapshot to the ESXi hosts, and triggers vSphere to cause the ESXi hosts to rescan the storage
- The ESXi hosts then see the new snapshot LUN, resignature the LUN, and mounts up the datastore
- The original VM is renamed with a .retired suffix.
- The VM to be restored is imported into the inventory and renamed with a .restored suffix
- The VM on the snapshot is then started, and you are back in production.
- After it starts, the original VM is deleted, and the restored VM is renamed back to the original name.
- The restored VM is storage vmotioned back to the original LUN.
- The snapshot datastore is unmounted, and then unpresented from ESXi.
All of these functions are of course available without the plug-in. However, the plug-in and it’s interface simplifies the snapshot and restore operations. This will be extremely useful in the SMB and mid-market where the IT professionals supporting this technology are generalists and support multiple technologies for their organization. This should lower the barrier to using snapshots for the primary recovery mechanism.