3 Replies Latest reply on Feb 20, 2007 1:51 AM by neil_murphy

    VMotion with Datastore Relocation

    neil_murphy Enthusiast

      Hi,

       

      I am prpeparing to do an upgrade for a customer and I want to do a VMotion with Datastore Relocation type upgrade on some very large VMs (100's of GB). My customer is extremely cautious and wants to know:

       

      1. Exactly what is happening to the vmdk's during the migration.

      2. What is the roll-back procedure should the procedure fail.

      3. How fast will the process be.

       

      Any thoughts?

        • 1. Re: VMotion with Datastore Relocation
          Jwoods Expert

          During my upgrade to VI3 I moved 3 VMs that were between 250Gb and 400GB.  2 of the 3 migrated hot.  The 3rd failed during the migration.  HOWEVER, I was able to continue a cold migration of that VM.  Upon completion it started without a hitch. 

           

          1. Exactly what is happening to the vmdk's during the

          migration.

          Virtual Center makes a copy of the VMDK leaving the original VMDK on the source lun until the Dmotion process is completed.

           

          2. What is the roll-back procedure should the

          procedure fail.

          During the Dmotion process, there is another VMDK created on the destination VMFS lun labeled <vmdk-name>-[b]dmotion[/b].vmdk.  Should the process fail for any reason, the procedure is to shutdown the VM.  At this point there is an option to continue the migration (I forget the exact wording).  So I recommend you perform a few test migrations to get familiar with the process and see what actually occurs during and after the Dmotion.

           

          3. How fast will the process be.

          I recorded timings for each migration.  Of course they'll be different in your environment...

          10GB --> 4min

          50GB --> 23min

          110GB --> 35min

          250GB --> 1hr32min

          310GB --> 2hr21min

          400GB --> 3hr6min

           

          Message was edited by:

                  Jwoods

          1 person found this helpful
          • 2. Re: VMotion with Datastore Relocation
            Nautilus Hot Shot

            Hi,

             

            I am prpeparing to do an upgrade for a customer and I want to do a VMotion with Datastore Relocation type upgrade on some very large VMs (100's of GB). My customer is extremely cautious and wants to know:

             

            1. Exactly what is happening to the vmdk's during the migration.

            vmotion, reallocation ? nothing will be reallocated with vmotion. I Think the best way is, vmkfstools -i... to duplicate the vmdk file, the safest way !

             

            2. What is the roll-back procedure should the procedure fail.

            try it again

             

            3. How fast will the process be.

             

            depending on your hardware !

             

            Any thoughts?

            1 person found this helpful