VSS application snapshot with Hyper-V 2008R2 Cluster

[Alex Ball]

Anyone know if its even possible to a vss compliant snapshot on a Hyper-V cluster.

I just get the credentials error message even though they are configured.

Thanks

Alex

[IainS]

Yes, I've been experimenting with DPM 2010 (MS Data Protection Manager) against our 2 node cluster and have been able to get VSS snapshots working (after setting up default credentials - before this they would fail) and snapshots work fine for DPM backups.

We actually get multiple layers of snapshots at once which leads to some initially alarming over-provisioning of the cluster, however the actual used space doesn't go up. Things go back to normal after the snapshot(s) are deleted after the end of the backup.

The DPM agent on the Hyper V node initiates the VSS snapshot so I don't know much about what it is doing behind the scenes. I do know the DPM agent has to be all on Hyper V nodes and I think the credentials somehow carry through to all nodes (or else I set them up at different times and didn't remember).

[Jitun]

For HP P4000 VSS Provider, Installed Features Required:
Backup Server:
ï · Advanced Disk-based Backup Option (ADBO)
ï · Advanced Open File Option (AOFO)
ï · Remote Agent (Push out to App Server)
ï · Backup Provider
ï · VSS Provider
ï · Management group authentication set up for the VSS Provider

Application Server:
ï · Remote Agent Client must be pushed out from the Backup Server and must include the AOFO to the Application Server
ï · VSS Provider
ï · Management group authentication set up for the VSS Provider

As long as you have
ï · Advanced Disk-based Backup Option (ADBO)
ï · Advanced Open File Option (AOFO)
Compliant Backup App, HP VSS would work fine.

I do believe it should be Compliant.

[Alex Ball]

I guess really I wanted to initiate the snapshot from the CMC console and snapshot a whole CSV LUN. I'm not so intrested in initating it from the backup program.

I want to use the snapshot ability on the SAN to take the snapshot as opposed to using a hyper-V snapshot

[IainS · Accepted solution]

I'm not sure you can do that and get a safe backup of it. I believe you need to have some sort of cluster aware agent on the Hyper V nodes to tell the guest VMs and the Hyper V hosts to do their VSS magic or else you might get an inconsistent snapshot. Sure it will represent the disk at that exact time, but that might include some data that was in the process of being written to that is effectively corrupt until the other writes in progress at the time completed.

In addition I don't think it is safe to just have one Hyper V cluster node involved. I think the one currently hosting the guest needs to be involved.

It might work, but you risk getting some corruption.

[Jitun]

I would suggest using Application Managed Snapshots as shown in the attached pic