locked
Is fault tolerance possible with Hyper-V Server 2012? RRS feed

  • Question

  • Hi all.

    Can the fault tolerance feature be used with Hyper-V Server 3.0 (2012)?  Or do I have to have use Windows Server 2012 with the Hyper-V role and the fault tolerance role enabled?

    Thanks!

    Monday, October 15, 2012 9:54 PM

Answers

All replies

  • You mean FT in VMWARE ? If u mean this, then the answer is NO.

    http://www.windowsitpro.com/article/hyper-v-server/fault-tolerant-143529

    Tuesday, October 16, 2012 6:26 AM
  • Hi,

    High availability solutions traditionally consist of a set of loosely coupled servers which have failover capabilities. Each system is independent and self-contained, yet the servers are health monitoring each other and in the event of a failure, applications will be restarted on a different server in the pool of the cluster. 

    Fault tolerant solutions traditionally consist of a pair of tightly coupled systems which provide redundancy. Generally speaking this involves running a single copy of the operating system and the application within, running consistently on two physical servers.

    I think in Windows Server 2012, Hyper-V Replica Feature is more like Fault tolerant.

    With Hyper-V Replica, administrators can replicate their Hyper-V virtual machines from one Hyper-V host at a primary site to another Hyper-V host at the Replica site. This feature lowers the total cost-of-ownership for an organization by providing a storage-agnostic and workload-agnostic solution that replicates efficiently, periodically, and asynchronously over IP-based networks across different storage subsystems and across sites. This scenario does not rely on shared storage, storage arrays, or other software replication technologies. The following figure demonstrates how Hyper-V Replica lets administrators easily replicate virtual machines to a remote site over a WAN link.

    High Availability Solutions and Fault Tolerant Solutions they protect against different types of scenarios. The key aspect to understand is what are the most important to you and your business requirements.

    For more information please refer to following MS articles:

    Evaluating High-Availability (HA) vs. Fault Tolerant (FT) Solutions
    http://blogs.msdn.com/b/clustering/archive/2010/10/06/10072013.aspx
    Hyper-V Replica Feature Overview
    http://technet.microsoft.com/en-us/library/hh831716.aspx
    Hyper-V Replica Overview
    http://technet.microsoft.com/en-us/library/jj134172.aspx


    Lawrence

    TechNet Community Support

    Tuesday, October 16, 2012 7:30 AM
  • Hi all.

    Can the fault tolerance feature be used with Hyper-V Server 3.0 (2012)?  Or do I have to have use Windows Server 2012 with the Hyper-V role and the fault tolerance role enabled?

    Thanks!

    There's no Fault Tolerance with Hyper-V... You have such an options:

    1) Application built-in clustering (SQL Server database mirroring & log shipping for example)

    2) Guest VM cluster (should work with pretty much with everything including MS iSCSI target)

    3) Third-party software to simulate FT as close as possible (for example from Marathon: 

    http://www.marathontechnologies.com/fault_tolerant_windows_servers.html

    (never used their stuff however)

    Generally speaking 1) and 2) should be fine for 99% of cases. The only two real use cases I know for FT are both linked with military and

    supporting ancient databases running as non-Windows applications.


    StarWind iSCSI SAN & NAS

    • Proposed as answer by VR38DETTMVP Tuesday, October 16, 2012 12:28 PM
    Tuesday, October 16, 2012 12:27 PM
  • I think in Windows Server 2012, Hyper-V Replica Feature is more like Fault tolerant.

    Lawrence, with all my respect to you the whole idea behind Fault Tolerance is 1) non-disruptive service and 2) no data loss. Neither 1) nor 2) could be achieved with Hyper-V replica... Don't get me wrong I think it's a great feature but it's not a Swiss Army knife :)

    StarWind iSCSI SAN & NAS

    Tuesday, October 16, 2012 12:31 PM
  • Stratus had a fault-tolerant solution for Hyper-V 2008.  I just checked www.windowsservercatalog.com and don't find anything for them certified on 2012.

    And, when it comes to the term 'fault tolerant', I have seen many people misunderstand what it means.  Many, many times when I question people who have asked me about fault tolerant solutions, I have found they are really asking for a high availability solution - a fault resistant solution - that is readily provided by failover clusters or some other technology.  So, I agree 100% that failover clusters are not considered fault tolerant, but until the original poster really defines what was meant by his/her use of that term, we should not shut down the conversation trying to assist.


    tim

    Tuesday, October 16, 2012 12:57 PM
  • Thanks everyone!

    What I am trying to do is to create a failover cluster, so that if one of the host servers fails the virtual machines will instantly switch over to another host server in the cluster without any down time or data loss for my virtual machines. 

    Would this be possible with two (or more) servers running Windows Server 2012 Data Center with the Hyper-V role and the failover clustering feature installed; along with a SAN to store the virtual machines?

    Wednesday, October 17, 2012 12:17 AM
  • Absolutely possible.  That is most likely the most common installation of Hyper-V you will find.

    However, there is downtime if a host fails.  If the host fails, the virtual machines that were running on the failed host have to restart on the surviving node.  If there is planned downtime, you can live migrate the VMs to the other node to ensure the VMs continue operating.


    tim

    Wednesday, October 17, 2012 12:20 AM
  • Absolutely possible.  That is most likely the most common installation of Hyper-V you will find.

    However, there is downtime if a host fails.  If the host fails, the virtual machines that were running on the failed host have to restart on the surviving node.  If there is planned downtime, you can live migrate the VMs to the other node to ensure the VMs continue operating.


    tim

    Thanks Tim!

    So is there anyway to provide continuous uptime for the virtual machines?

    Wednesday, October 17, 2012 1:38 AM
  • Hi,

    Please refer to below example, runs Hyper-V in the context of a two-node failover cluster.

    Shortly after heartbeat signals stop arriving from Node 1, Node 2 begins an orderly process of taking over the functionality of VMachine1 and VMachine2. For each of the virtual servers, Node 2 brings resources (such as virtual disks) online in an orderly fashion, as specified (by the administrator) in the failover cluster configuration. If one resource depends on another resource being present, that dependent resource is brought online after the resource it depends on. On clients, there is only a short interruption of service, not noticed by most users. The following diagram shows failover occurring.

    A similar process can be initiated by a system administrator for scheduled downtime. For example, if Node 1 is running correctly and is the current owner of VMachine1 and VMachine2, but software updates need to be applied to Node 1, the administrator can use the Failover Cluster Management snap-in to deliberately move VMachine1 and VMachine2 to Node 2 so that the software updates can be applied. Of course, when applying software updates to a cluster node, it is important to apply the same updates to other cluster nodes as soon as possible. This ensures that all cluster nodes will consistently respond in the same way.

    For more information please refer to following MS articles:

    Example, Failover Cluster in Which All Nodes Run Hyper-V
    http://technet.microsoft.com/en-us/library/dd197581(v=ws.10).aspx#BKMK_Hyper_V_after
    Hyper-V: Using Hyper-V and Failover Clustering
    http://technet.microsoft.com/en-us/library/cc732181(v=WS.10).aspx


    Lawrence

    TechNet Community Support

    • Proposed as answer by VR38DETTMVP Wednesday, October 17, 2012 8:53 AM
    Wednesday, October 17, 2012 8:23 AM
  • Absolutely possible.  That is most likely the most common installation of Hyper-V you will find.

    However, there is downtime if a host fails.  If the host fails, the virtual machines that were running on the failed host have to restart on the surviving node.  If there is planned downtime, you can live migrate the VMs to the other node to ensure the VMs continue operating.


    tim

    Thanks Tim!

    So is there anyway to provide continuous uptime for the virtual machines?

    Sure. Don't run HA for VMs, configure guest VM failover cluster. Then you'll have zero downtime in case of an unplanned physical node going down.


    StarWind iSCSI SAN & NAS

    Wednesday, October 17, 2012 8:52 AM
  • Sure. Don't run HA for VMs, configure guest VM failover cluster. Then you'll have zero downtime in case of an unplanned physical node going down.

    Good point. Clustering VMs instead of the host gives a different sort of failover, but, depending on the application, there may still be downtime.  Not as long, still there.

    tim


    Wednesday, October 17, 2012 2:22 PM
  • Thanks guys!

    So inorder to make a failover cluster could I follow the steps outlined in this video, http://technet.microsoft.com/en-us/video/3-hyper-v-r2-building-a-hyper-v-r2-cluster.aspx?


    Wednesday, October 17, 2012 7:32 PM
  • Thanks guys!

    So inorder to make a failover cluster could I follow the steps outlined in this video, http://technet.microsoft.com/en-us/video/3-hyper-v-r2-building-a-hyper-v-r2-cluster.aspx?


    Yes. Unless you run FC and want to use FC-based clustering with Windows Server 2012.

    StarWind iSCSI SAN & NAS

    • Marked as answer by The Black Rock Wednesday, October 17, 2012 9:21 PM
    Wednesday, October 17, 2012 7:48 PM
  • By FC do you mean Fiber Channel?  As in connecting the host nods to a fiber switch?
    Wednesday, October 17, 2012 8:17 PM
  • By FC do you mean Fiber Channel?  As in connecting the host nods to a fiber switch?
    Yes. Before Windows Server 2012 you had to use iSCSI with guest VM cluster. Now you can also use FC. If you run FC stack it eliminates the need of having iSCSI on top of FC to feed shared storage to guest VM clusters. 

    StarWind iSCSI SAN & NAS

    • Marked as answer by The Black Rock Wednesday, October 17, 2012 9:21 PM
    Wednesday, October 17, 2012 9:16 PM
  • Great, thanks! 
    Wednesday, October 17, 2012 9:21 PM