6 Replies Latest reply on Dec 10, 2012 7:24 AM by EcoBassam

    Corrupted templates after snapshot removal

    EcoBassam Enthusiast

      Hi,

       

      I did some manual snapshot delete directly on the Virtual Center and it caused some templates on VCD to be corrupted (because of the linked clone functinnality I think). When I try to access the catalog where the corrupted template exist, I have the following message :"vCloud Director created snapshots was deleted in VirtaulCenter. Refer to the vCloud Director user's guide to take appropriate action." but I find nothing on the user guide.

       

      How do I recover from this bad situation ? a lot of templates are impacted.

       

      Thanks in advance for your help.

        • 1. Re: Corrupted templates after snapshot removal
          cfor Expert
          vExpert

          Not 100% sure this will work for you - but a good quick test (but do one something that is you loss you can rebuild).

          Attempt a consolidate on one of the VM's in questions (from inside VCD)

          This will remove the snapshots and link back to the base VM.  It might work.

          1 person found this helpful
          • 2. Re: Corrupted templates after snapshot removal
            EcoBassam Enthusiast

            I have tested this and now I can deploy from that template. But the message is still present and I don't know if this has other impact beacause of the linked clone usage, may be some running VMs based on these templates will crash when they need to access the information deleted to the removed snapshot ?

            • 3. Re: Corrupted templates after snapshot removal
              cfor Expert
              vExpert

              Many times these errors auto-clear.

               

              But if they do not you can force clear them, and if they do not come back the system thinks it is ok.  (To force clear I have had to update the database, support was able to assist with this)

               

              The only way I know to tell if you causes issues with things downstream of the templates is to go test them.  In the past I have done something similar and got lucky without issue.

              1 person found this helpful
              • 4. Re: Corrupted templates after snapshot removal
                EcoBassam Enthusiast

                Actually I am asking myself this question: Is it normal that VMs managed by VCD has snapshots on VC ? If yes , what is the action the creates them ?

                • 5. Re: Corrupted templates after snapshot removal
                  cfor Expert
                  vExpert

                  Fast Provision does this.

                   

                  The way "linked clones" work - the method used for Fast Provision - is to create a snaptshot, then each new instance is linked by getting a new delta file created.

                   

                  So basic process:

                  Template VM is snapshoted by VCD.

                  The base disk of the snapshot is then used as the master disk for each new VM.

                  Each new Vm will get a delta disk for it's changes.

                   

                  So fastprovision does not come free, it may save a bunch of disk, but it does require delta disk and the alignment and speed issues that go with them to be possible.  (However in many cases I have found Fast Provision is still very nice and worth it)

                  • 6. Re: Corrupted templates after snapshot removal
                    EcoBassam Enthusiast

                    Sorry for my late reply. I saw this with VMware Support.

                    I consolidated the templates and cleared the error messages.

                    The snapshot removal has no impact on already running VMs because they make reference to the template disk and not to the snapshot file.

                     

                    For what said cfor on the preceding message :

                    ChrisF wrote:

                     

                    Fast Provision does this.

                     

                    The way "linked clones" work - the method used for Fast Provision - is to create a snaptshot, then each new instance is linked by getting a new delta file created.

                     

                    So basic process:

                    Template VM is snapshoted by VCD.

                    The base disk of the snapshot is then used as the master disk for each new VM.

                    Each new Vm will get a delta disk for it's changes.

                     

                    So fastprovision does not come free, it may save a bunch of disk, but it does require delta disk and the alignment and speed issues that go with them to be possible.  (However in many cases I have found Fast Provision is still very nice and worth it)

                     

                    The correct statement is : The base disk of the template is then used as the master disk for each new VM.

                    The role of the snapshot is just protection of the base disk of the template in case the vCenter Admin starts the template by error, all modifications will be written on the snapshot file.

                     

                     

                    Regards,