When you use a third-party backup application to back up your Virtual Machines (VM) that are in a guest cluster by using shared virtual disk (VHDS), you may receive one or more of the following error messages:
Error code: '32768'. Failed to create checkpoint on collection 'Hyper-V Collection'
Error code: '32770'. Active-active access is not supported for the shared VHDX in VM group
Error code: '32775'. More than one VM claimed to be the owner of shared VHDX in VM group 'Hyper-V Collection'
Error Event 19100 Hyper-V-VMMS 19100 'BackupVM' background disk merge failed to complete: General access denied error (0x80070005)
For error 1
This issue occurs because Windows can't query the cluster service inside the guest VM. To fix this issue, make sure that the cluster feature is installed on all guest VMs and is running.
For error 2
This issue occurs because the VHDS disk is used as a Cluster Shared Volume (CSV), which cannot be used for creating checkpoints. To fix this issue, you need to use each disk as a shared disk instead of as a Cluster Shared Volume. This can be done by using the Remove from Cluster Shared Volume option.
For error 3
This issue occurs because the shared drive was offline in the guest cluster. To fix this issue, make sure that all shared drives in the cluster that are part of the backup are online.
For error 4
This issue occurs because of a permission issue. To fix this issue, the folder that holds the VHDS files and their snapshot files must be modified to give the VMMS process additional permissions. To do this, follow these steps.
- Determine the GUIDS of all VMs that use the folder. To do this, start PowerShell as administrator, and then run the following command:
get-vm | fl name, idOutput example:
Name : BackupVMId : d3599536-222a-4d6e-bb10-a6019c3f2b9b Name : BackupVM2Id : a0af7903-94b4-4a2c-b3b3-16050d5f80f
- For each VM GUID, assign the VMMS process full control by running the following command:
icacls <Folder with VHDS> /grant "NT VIRTUAL MACHINE\<VM GUID>":(OI)F
icacls “c:\ClusterStorage\Volume1\SharedClusterDisk” /grant "NT VIRTUAL MACHINE\a0af7903-94b4-4a2c-b3b3-16050d5f80f2":(OI)Ficacls “c:\ClusterStorage\Volume1\SharedClusterDisk” /grant "NT VIRTUAL MACHINE\d3599536-222a-4d6e-bb10-a6019c3f2b9b":(OI)F