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I have a W2K8 R2 Datacenter server running Hyper-V with a Equallogic PS4100 SAN. I 5 virtual machines running in production. I now have a second server and would like to set both up for clustering. The servers, OS, etc. are all the same but my question is how or can I cluster them without removing or adversely affecting the 5 VM's in production? Do I need to shut them down and move them and start from scratch or can I do this with them in place?


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While you're at it why not read the documentation MS provides about how to do this then come back to us with specific questions. Please and thank you. – Chopper3 Jul 31 '12 at 16:47
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In order to do what you want to do, you would have had to plan for this situation in advance. You can set up a single Hyper-V host with storage that a second potential future host could share. And you can set up that one and only host as a cluster with no other members.

Then, later, you can add nodes to that cluster. But you cannot turn a single host into a cluster without taking it down for some period of time.

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I hadn't thought of that method. I can take my new server which is sharing the same volume on the SAN, add the cluster role, add the hyper-v role, then shutdown the vm's on the live box and bring them up on the new box. Then add the original live box as the 2nd node of the cluster. This would require very minimal downtime. And worst case scenario something goes wrong with the new box and bringing up the vm's I just shut it down and bring up the original box with the vm's. – PBK Aug 1 '12 at 17:26
It's also worth noting that, with Server 2012, you could have brought up the new server and then migrated the VMs to it even without having the original host be part of a cluster. I know that doesn't help right now, though. – Jake Oshins Aug 1 '12 at 21:45

In order to cluster Hyper-V virtual machines, you need the VMs to be on a shared storage which can be accessed by all cluster nodes; since you are using an iSCSI SAN, this should already be your case. You need to set up the cluster and then configure the VMs as cluster resources. In order to do this, you'll need to shut down the VMs, but if they are already stored on the SAN, you will not need to move them around.

Setting up a failover cluster can be tricky (pay special attention to your network setup), but it's by no means a terribly difficult task. These links should help:

Also, please note that in order to have a failover cluster on Windows systems, you need the nodes to be part of an Active Directory domain; if you don't have one, you'll need to set it up. And please don't use a virtual machine running on the same cluster as your domain controller... this is the worst thing you can do if you want your cluster to survive a reboot.

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Just a note... you can run the DCs as VMs just have another physical DC box as well... its not real funny when you can start the cluster because AD is not available... been there done that. – Brent Pabst Jul 31 '12 at 18:56
Yes, that's exactly what I was meaning :-) A virtual DC is fine... just make sure it isn't the only one you have. – Massimo Jul 31 '12 at 20:50
Thanks for the info. I have researched this but haven't found anything concrete on setting up clustering with a live Hyper-V install. Everything I have found has said setup envir. -> cluster -> then add Hyper-V role -> copy vm's or create vm's. I would love to find an article that says I can cluster after having setup the Hyper-V role. Now I am thinking because the vhd's are on the SAN I should maybe shut them down -> remove the role -> cluster -> add the role -> recreate the vm's using the vhd's. Problem is I am a little hesitant with only a small maintenance window on a Sun to do this. – PBK Aug 1 '12 at 16:56
Adding Clustering to Hyper-V after the fact works just fine. I've personally done it without problems. After you're done with setting up the cluster you have to add the non-clustere VMs to the cluster with the Failover MMC. Clustered Hyper-V does NOT automatically make all VMs highly available. – Chris S Aug 1 '12 at 17:04
You actually need to shut down the VMs in order to configure them as cluster resources. This can't be done on running VMs. – Massimo Aug 2 '12 at 19:10

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