6 Replies Latest reply on Dec 17, 2019 1:06 AM by AmazingTed

    2 Host vSAN Cluster

    AmazingTed Novice

      Just clarifying, i have a 2 host vSAN cluster that i have created, everything is fine but when i try and edit the storage policy my vSAN DS is showing as incompatible, and i am unable to wrtie anything to the vSAN datastore (Create folders in DS browser etc.)

      Claimed the disks to the relevant disk groups and tiers, hosts are seeing each other, however for some reason i see:

       

      'Datastore does not match current vm policy "storage fault has occurred"'

       

      Refreshed the Storage providers to no avail and the Disk groups/datastore is seen just for some reason not compatible.

       

      Do i have to specify that its a 2 host cluster through the new vCenter HTML5 config screens for the storage to be usable?

       

      If i set the PFT to 0 in the storage policy the storage becomes compatible, i am currently unable to test with a 3rd host or a witness appliance but will do as soon as available, just curios in the meantime.

       

       

      Thanks.

        • 1. Re: 2 Host vSAN Cluster
          TheBobkin Virtuoso
          VMware EmployeesvExpert

          Hello AmazingTed,

           

          It is completely expected behaviour to not be able to create Objects which require 3 Fault Domains (e.g. as the Default vSAN Policy is configured) when you only have 2.

           

          Edit: Your options with only 2 nodes available are FTT=0 or FTT=1 with ForceProvisioning enabled (but this won't really improve availability just increase space usage).

           

          Bob

          • 2. Re: 2 Host vSAN Cluster
            AmazingTed Novice

            Thanks Bob, but you can have a 2 host cluster though with a witness appliance with a PFT of 1 right? in a RAID1 config?

             

            Would this require just creating a new storage policy away from the default, or are you saying there is a minimum requirement of 3 hosts for any vSAN redundant deployment?

             

            Your other comment helped me out a treat BTW with the disks not being discovered...

            • 3. Re: 2 Host vSAN Cluster
              TheBobkin Virtuoso
              VMware EmployeesvExpert

              Hello AmazingTed,

               

              Correct, there is a minimum requirement of 3 available Fault Domains (nodes or sites) for FTT=1,FTM=RAID1 Storage Policies - it basically does the same thing in a Stretched/Direct-connect configuration except it stores all the witness components on the Witness as opposed to distributing them.

               

              Happy to help with regard to the other thing, I unfortunately see it all the time .

               

              Bob

              • 4. Re: 2 Host vSAN Cluster
                AmazingTed Novice

                OK, so introducing the Witness host will allow me to have FTT=1 with 2 actual nodes?

                 

                The storage requirements of the Witness host though are small as its only Witness components so its storage isn't factored into the vSAN Datastore?

                • 5. Re: 2 Host vSAN Cluster
                  TheBobkin Virtuoso
                  VMware EmployeesvExpert

                  Hello AmazingTed,

                   

                  Correct.

                  Witness components are comparatively tiny and are not read/write intensive so their storage requirements are minimal.

                   

                  Bob

                  • 6. Re: 2 Host vSAN Cluster
                    AmazingTed Novice

                    Adding the witness host from marked the vSAN DS as compatible for the VM policiy.

                     

                    Shame you can only get the 2 host cluster option int he HTML5 config wizard.