Hyper V Configuration Question

Hi Everyone, just wanted to put this question out there.
I have a physical server running Server 2012 R2 with Hyper V.  Hyper V has 3 VMs, TS, Exchange 2016 and SQL 2008.
I want to do fail over cluster with a second box.
Can I just buy a second physical box, put 2012 R2 on it, install Hyper V on it and sync all the VMs over?

My searching online seems to say no, but there seems to be some that say you can.
I'm guessing I need a NAS or a SAN to put the Data on like Exchange store (DAG) and SQL Databases along with a dedicated IP network to run the replication data over, am I wrong?

Any input or ideas (clarification) would be appreciated!
Who is Participating?
Adam BrownConnect With a Mentor Sr Solutions ArchitectCommented:
You can sync the VMs on a second Hyper-V host without any problems. https://blogs.technet.microsoft.com/canitpro/2013/04/07/step-by-step-virtual-machine-replication-using-hyper-v-replica/ goes over the process. Now, this is not a "Failover Cluster" in the classic sense, but will allow you to fail over to the second VM quickly on demand or start the VMs up on the second server if the first one fails. A failover cluster would require a Cluster Shared Volume (A disk array that is available to all cluster members, so a SAN would work), but would instantly fail over without any interaction required.

That said, VM replication and Clustering of the VM Host is not as effective a solution as configuring Two Exchange/SQL servers with DAG capabilities. DAG doesn't require a cluster shared volume to work, but does take more storage space, since each server would have to have enough space to hold its own copy of the DB files. For this configuration, you would set up an Exchange and SQL VM on each Hyper-V host, then configure them as members of their individual DAGs. a Load balancer will help you considerably with this, but isn't necessarily required.
Cliff GaliherConnect With a Mentor Commented:
That isn't a failover cluster though.

2012 R2 needs shared storage if you want a real cluster. And yes, you want a back-end dedicated network.  But you asked if you needed a dedicated network for replication. That answer is no, because there is no replication happening. Zero. None. The dedicated back-end network is for node coordination, not replication.

The proposed solution, Hyper-V replica, does *not* required shared storage, but is not real time replication either. It happens at intervals, and requires manual fail-over and fail-back, as well as planning for those events.  It is a reasonable inexpensive DR solution, but should *not* be considered the same as a failover cluster, which offers significantly less risk of data loss and higher availability. If you need those things, there is no substitute.  Apples and oranges
2ndFloorAuthor Commented:
Great feed back! Thank you Adam and Cliff!

So there are three options:

1) Hyper V replication - cheap (no need for NAS or SAN) but no auto fail over.  Just need 2nd Server + OS with Hyper V

2) 2 Node Cluster - needs a SAN, dedicated secondary IP Network but has auto fail over

3) DAG - Needs a second copy of Exchange and SQl Server on second Server Virtual Machines, does not need SAN/NAS or secondary IP network
Alex AppletonBusiness Technology AnalystCommented:
If you want a cluster on 2012 R2 you are going to need shared storage.  You can configure a 2 node iSCSI cluster on the cheap, but please be careful about what you use for your shared storage appliance because this is going to be your most important piece.   I wrote up a step by step on setting up a 2 node Hyper-V cluster on 2012 R2 using iSCSI here:  http://alexappleton.net/post/44748523400/step-by-step-configuration-of-2-node-hyper-v

Alternatively, if you update your hosts to 2016 (Datacenter license) you can do S2D hyper-converged cluster.  I think this would be more along the lines you are looking for.  Check that out here:  https://docs.microsoft.com/en-us/windows-server/storage/storage-spaces/hyper-converged-solution-using-storage-spaces-direct
2ndFloorAuthor Commented:
Thank you for the quick responses!
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