VMware vSphere

 View Only
  • 1.  Migrate Two DataStores to One DataStore Cluster

    Posted Aug 27, 2020 05:23 PM

    I have two separate datastores for VMS (VMs1 and VMs2). Both are external NAS (RAID 10) devices and they are the exact same size. All of my VMs would fit on one of these, without an issue. 

    I have two questions:

    (1) does a DataStore Cluster work similarly to a Host Cluster, whereby if one of the datastores in the cluster fail, the remaining datastore(s) will run everything? Basically, does ESXi manage the redundancy?

    (2) If #1 is true, if I attempt to make my two separate datastores into a DataStore Cluster does ESXi erase/wipe or otherwise is the VMs on each removed to make the cluster?  (Do I need to shut down all VMs and back them all up to an external device to create a DataStore Cluster?

    Any input/feedback is greatly appreciated.


  • 2.  RE: Migrate Two DataStores to One DataStore Cluster
    Best Answer

    Posted Aug 27, 2020 05:37 PM


    No, Datastore Cluster does not work that way.

    The benefit of DSClusters is Space utilization load balancing I/O latency load balancing.

    You dont need to touch or move your vms to create a datastore cluster and add datastores into it. Is not the same behavior as Host Clusters.

    If your requirement is to have the VMs available in both DS in case of failure, you have multiple options:

    vSphere replication (You can replicate your VMs from one DS to the Another and have them in case of failure)

    Backup (store a backup in the secondary DS)

    FaultTolerance (You can keep the secondary VM in the other datastore and in case of failure the vm will be available) - Aditional limitations in this one

    All those are workaround, not "solutions".

    From my point of view, you need to have a backup/replication and in case of failure you will be able to recover.

    Hope that helps


  • 3.  RE: Migrate Two DataStores to One DataStore Cluster

    Posted Aug 27, 2020 05:47 PM

    Hi Nicolas, thanks for the reply.

    I do have a nightly process that backs up both datastores to external devices. I was mostly looking for a solution if one datastore (for some reason) goes down.  I recently had a situation where the UPS attached to one of the datastore NASs powered off.  I have no idea why or how the UPS simply powered off.  But that is beyond this post.

    Thank you for the thorough reply and options.  I have some reading to do now.