Small Business Susan

Where does your DC go?


So where should be your DC in a virtual machine setup?


Should you do snapshots of virtual machines?


For the first – I’ve been told never ever ever do a domain controller that has the hyperV role.  But when I went looking for info on how this is not supported – I’m finding blog posts that are more wiggly – http://blogs.msdn.com/b/virtual_pc_guy/archive/2008/11/24/the-domain-controller-dilemma.aspx


In my office I’m using the parent as a workgroup.  So that it’s independent of the domain.  One item of note in that blog post is the statement that if you have the dc role and the HyperV role together, you need to shut down the HyperV children before rebooting the box.  Right now in my workgroup mode, when I patch I don’t.  I just reboot the box, the hyperV does a ‘saved state’ and then turns back on when done.


“You should never use saved state / snapshots with domain controllers – as this can be catastrophic”


Yet that post indicates that saved state is a no no?  Mind you I only have one Domain controller so that the issue of tombstoning won’t occur.


I do not take snapshots on domain controllers, nor on my real HyperVs.  I’ve taken a snapshot on my test box and accidentally  put the snapshot files in a small size drive and ran the drive out of room.  This in turn paused the child machines.  Thus I’m not comfy with snapshots on real virtual machines for fear of my stupidity kicking in.


I’ll be adding some of these comments to the HyperV for SMB build doc.



2 comments ↓

  • #   SeanPT on 08.19.12 at 1:42 pm     

    Years ago I spoke at length on saved states and sbs2008. The general agreement was in a one dc environment things are less problematic but it was “unsupported”. So I always set the vm to shutdown. Then I ran into those long sbs2008 shut downs. The hyperv host got sick of waiting for the vm to shutdown and I think it would either save state anyways or force shutdown.

    So I went to save state land and it worked fine and with sbs2011 in single dc environments I also used save state. I’ve never run into exchange, SQL / Sharepoint or dc issues with save state but again — this is the old DBS world where these were single instances.

    My thought going forward was to continue to save state and continue to keep the hyperv host(s) off the domain.


  • #   SPLA on 08.20.12 at 9:49 am     

    I’ve got one client running SBS 2008 as a VM on hyper-v (actually a full 2008 R2, which helps for backup). I *always* shut down the VM, however, if I’m in a hurry I run a script to do this from within SBS, which stops the Exchange services before doing a shutdown.exe. This speeds up the shutdown enormously.

    The host is standalone, not joined to the SBS domain. I haven’t tried, but maybe I could do GPO to run the script, which would be triggered by asking the physical host to shut down. Depends on whether a shutdown initiated by hyper-v IC triggers the GPO…

    I also run SBS 2011 on a hyper-v cluster, but here I can avoid having to save state/shut down as I can just live migrate to another node.