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Hyper-V replica vs failover cluster RRS feed

  • Question

  • Hi,

    What is the difference between a Hyper-V failover cluster and a Hyper-V replica setup?

    Thanks

    Saturday, August 10, 2013 12:49 AM

Answers

  • Hi,

    What is the difference between a Hyper-V failover cluster and a Hyper-V replica setup?

    Thanks

    These are totally different solutions implemented to solve different issues. Failover cluster is for business continuity and H/V replica is for disaster recovery. So they are complimentary to each other rather then competitive approaches. Both can failover VM from one physical node to the other but H/V replica does lose some data and does not do transparent failover (cluster does not lose data and does transparent failover from the other side). Also cluster does not put that heavy load on the network as it uses shared storage. H/V replica does not use shared storage so it has to synchronize all the changes over the network. So if you have very flexed RTO/RPO then you can simply skip using cluster (and maybe a backup app as well) and use only H/V replica. However if you want a guaranteed uptime and flexible recovery process you need all of them: replication, cluster and backup.

    StarWind iSCSI SAN & NAS

    • Proposed as answer by VR38DETTMVP Sunday, August 11, 2013 8:06 PM
    • Marked as answer by Vivian_Wang Wednesday, August 14, 2013 2:22 AM
    Sunday, August 11, 2013 8:06 PM

All replies

  • Failover cluster protects against server level failures.  Hyper-V replica can protect against site level failures; i.e. replicate one cluster to another.  I suppose you could replicate server to server in the same site without clustering but I think that would be more difficult to manage and slower to recover.
    Saturday, August 10, 2013 1:26 AM
  • Hyper-v failover cluster  allows us to create highly available virtual machines using a method called Active-Passive clustering.  That means that your virtual machine is active on one cluster node, and the other nodes are only involved when the active node becomes unresponsive.

    See more here : http://technet.microsoft.com/en-us/library/cc732181(v=ws.10).aspx

    Hyper-V Replica, as a built-in replication mechanism at a virtual machine (VM) level. Hyper-V Replica can asynchronously replicate a selected VM running at a primary site to a designated replica site across LAN/WAN

    See here http://blogs.technet.com/b/yungchou/archive/2013/01/10/hyper-v-replica-explained.aspx

    Also see the blog post is explained  more

    http://www.aidanfinn.com/?p=12147


    • Edited by Seneej Saturday, August 10, 2013 1:15 PM correction
    Saturday, August 10, 2013 1:08 PM
  • Hi,

    I actually just went through some technet labs on this, so now got a better idea.

    Yep, replica seems to be @ the vm level. So I guess if I had 2 hyper-v servers running 1 vm each (of course, very unlikely in prod but this is hypothetical) and I wanted to keep this 1 vm online while I replaced hardware on the host, I can use replication.

    Do any of these concepts protect against a sudden crash?

    Also, does Hyper-V replica not make use of the failover cluster? (I can't remember now in the labs).

    Sunday, August 11, 2013 1:34 AM
  • Hi,

    What is the difference between a Hyper-V failover cluster and a Hyper-V replica setup?

    Thanks

    These are totally different solutions implemented to solve different issues. Failover cluster is for business continuity and H/V replica is for disaster recovery. So they are complimentary to each other rather then competitive approaches. Both can failover VM from one physical node to the other but H/V replica does lose some data and does not do transparent failover (cluster does not lose data and does transparent failover from the other side). Also cluster does not put that heavy load on the network as it uses shared storage. H/V replica does not use shared storage so it has to synchronize all the changes over the network. So if you have very flexed RTO/RPO then you can simply skip using cluster (and maybe a backup app as well) and use only H/V replica. However if you want a guaranteed uptime and flexible recovery process you need all of them: replication, cluster and backup.

    StarWind iSCSI SAN & NAS

    • Proposed as answer by VR38DETTMVP Sunday, August 11, 2013 8:06 PM
    • Marked as answer by Vivian_Wang Wednesday, August 14, 2013 2:22 AM
    Sunday, August 11, 2013 8:06 PM