Ben Armstrong blogged last night about some of the changes that affect snapshots in Hyper-V running on Windows Server 2008 R2 and Hyper-V Server 2008 R2.
Before we mention them, it should be noted that you need to merge or delete your snapshots on the current release of Hyper-V before doing and upgrade to 2008 R2.
- You will be able to export a snapshot. In the background a merge is taking place to a new VHD file. You can then mount this or set it up as a new VM. It will appear as a new VM with no snapshots.
- AVHD files (your snapshots) will be created in the same folder as the VM’s VHD files. That makes them easier to find.
- Opening the properties of a snapshot shows you the related VHD files that are used to create the snapshot.
- You can edit an AVHD file to manually merge a snapshot.
- You will be able to manually attach snapshots to a VM. E.G. say you have a template VHD and you’ve built up some lab machines using snapshots. You can recreate that lab by copying the AVHD’s and attaching them to new VM’s.
I really don’t see snapshots as being something that should be used in production. For me, they’re limited to labs. The AVHD file is a kind of differencing disk and the performance isn’t great. You also need to be careful about AVHD bloat. If you need snapshot like behaviour in production then use a Hyper VSS enabled backup solution on the parent partition, e.g. DPM 2007 SP1.
I have a VHD and bunch of snapshots. For some reason, I wasn’t able to import the VM so now I had to create a new VM and attach the VHD to it. I don’t see any snapshots in Hyper-V. I want to attach the snapshots that I have. Where can I find some step by step instructions? Thanks.
You can only import and exported VM. The VM as it is stored on disk while it is running is setup in a slightly different way to an exported VM. I wish it wasn’t but it is.
The question is what do you want to end up with?
1) The VM as it was originally with a bunch of snapshots: There is a post out there somewhere for reconstructing a non-exported VM into an import layout but I cannot find it. I’m a bit busy in work at the moment.
2) You just want the VM back to it’s completed state with all data back: You can manually merge the snapshot files using http://blog.networkfoo.org/?p=384
There’s some info on snapshot configurations here:
http://windowsitpro.com/article/articleid/100427/q-what-happens-when-i-take-a-hyper-v-virtual-machine-vm-snapshot.html