Microsoft Virtualization Discussions

To SMHV or Hyper-V Snapshot - that is the question

I was wondering if someone could shed some light on the following question:

Now that SMHV has arrived, what are the benefits (pros/cons) of using SMHV to take a one-time snapshot of a VM over using the built-in capabilities of Hyper-V. For example, I am about to make a configuration change on a server or install an App, and I want to create a point-in-time copy of the VM. Before SMHV, I needed to do that via Hyper-V's snapshots, but there are some downsides of using that, such as (to name a few:

  1. You cannot resize a VHD file when there are snapshots
  2. You cannot reclaim space from deleted snapshots until after you shutdown the VM and wait a long time for the VHD to rebuild itself
  3. It is so much nicer to have your entire VM encapsulated into a single VHD file instead of a bunch of little snap files

The way I see it, SMHV gives me the same benefits with none of the cons listed above. Are there any cons to using SMHV for this purpose?




Re: To SMHV or Hyper-V Snapshot - that is the question

Hi Israel,

While by no means an SMHV expert, I have a few thoughts.

Concerning your intent to take snapshots before patches and application installs, SMHV will allow you to create OS and application consistent snapshots.  These will ensure that the OS and/or applications running are in a good state that can be restore to should the need arise.

In addition SMHV allows you to catalog the different snapshot(online back-ups) by name, date etc for each VM.  This would allow you to keep a list and maintain a list of the different snapshots and patch levels/application install statuses for your VMs.

It further integrates with snapmirror and snapvault if you wanted to keep a second copy in an alternate location on the filer or a secondary filer.

One con I can think of is that to use the restore capabilities to an earlier snapshot of the VM, would require purchase of a SnapRestore license. 

Hope this helps.

Dan Chilton