You may be aware of a constant debate that goes on between myself, Dave and a few others in education about running virtual environments and whether they should/could be 100% virtual of if you would need some physical domain controllers put into the mix. If you’re not familiar with the debate have a quick read of this http://sharepointineducation.com/?p=2056
So as you see, I’ve always maintained that you can have a completely virtual environment and in theory it’s all fine.
Well theory came crashing into reality this week. There was a planned power outage at school; the only flaw in the plan was that no one told us. We made it to the server room just in time to watch the UPS run out and experience the eeary sensation of a silent server room. One of the things to die was a fully virtual environment we have been playing with. The two node hyper v cluster is part of the same domain as the virtual machines that run on them. They both go off because of power and you have no domain. The theory being that you can just log in locally and start the DC, then boot 2nd node then reboot node 1. What I hadn’t taken into account was that the cluster would not load and the DC was not available to boot from the cluster manager.
Lessons were learnt. Here they are.
If running a fully virtual environment the failover cluster and associated cluster shared volume will not start as there is no domain – this is a problem.
We fixed it by removing the cluster volume and just assigning it a drive letter on node 1 of the hyper cluster, the VHD for the domain controller could then be copied onto the local C: of node 1 and fired up via hyper-v manager. The 2nd node could then be fired up and now having a domain to join was fine and the cluster volume was all good. The 2nd DC was then moved to the C: of node 2. Node 1 could then be restarted and all was good from then on.
So if you go fully virtual don’t put all your domain controllers in the cluster, keep them local, one on each node as they can be started independently of shared storage or cluster.
Although I still wouldn’t be brave stupid enough to do this in production 
You may also be interested in reading:
- HyperV Cluster Setup Part 5 This is the fifth and final part of the HyperV...
- HyperV Cluster Setup Part 4 This is the fourth part of the HyperV cluster setup...
- Saving Money with Virtualisation Using HyperV R2 As i said in a previous post in our preparation...
- HyperV Licencing of Guest Operating Systems As I have said I previous posts myself and Alan...
- Hyper V Cluster Setup Part 3 This is the third part of the HyperV cluster setup...
- SharePoint 2010 Topologies Part 3 In my previous post of this series I looked at...
4 comments
2 pings
AngryTechnician
August 13, 2010 at 2:00 pm (UTC 1) Link to this comment
I have to say when we chatted about this a couple of months ago, I hadn’t considered the clustering scenario, and I absolutely agree that keeping at least one outside the cluster is a very sound plan. While all my DCs are virtual, I actually don’t have any of them in a cluster; each one sits on the local RAID1 mirror on the host. I also compulsively set up a replica DC on every new host, just in case!
AngryTechnician
August 13, 2010 at 2:01 pm (UTC 1) Link to this comment
P.S. When I say “when we chatted”, I mean “when I chatted to Dave”. Didn’t spot which of you was the author of this post until after commenting!
cameron
August 13, 2010 at 7:31 pm (UTC 1) Link to this comment
yeah, i learned this same lesson about a while back, and did the same thing to correct it~
Cornelius J. van Dyk
August 18, 2010 at 10:04 pm (UTC 1) Link to this comment
I have my Hyper-V environment fully virtualized except for one thing. I have the host server as the domain controller. That way, if the host is up, the domain is up. Of course, my implementation is much smaller than yours and I don’t have clustered SQL!
Later
C
Tweets that mention Chris and Daves SharePoint and Tech Blog » Fully Virtualised Environments in HyperV. Theory meets reality head on! -- Topsy.com
August 13, 2010 at 2:11 pm (UTC 1) Link to this comment
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August 16, 2010 at 2:15 pm (UTC 1) Link to this comment
[...] Fully Virtualised Environments in HyperV. Theory Meets Reality Head On! (Chris and Daves SharePoint and Tech Blog)You may be aware of a constant debate that goes on between myself, Dave and a few others in education about running virtual environments and whether they should/could be 100% virtual or if you would need some physical domain controllers put into the mix. If you’re not familiar with the debate have a quick read of this http://sharepointineducation.com/?p=2056 So as you see, I’ve always maintained that you can have a completely virtual environment and in theory it’s all fine. [...]