Symptoms

Avamar Hyper-V backups may fail or complete with exceptions, having the below error:avhypervvss Error : Checkpoint creation for Virtual machine '' has failed and will be skipped from backup. For details, please check 'winclustersvc.log'.avhypervvss Info : --------------------Start [EMC Avamar Plug-in Service for Windows] log ----------The corresponding portion of winclustersvc.log (with DEBUG enabled), which is located in C:\Program Files\avs\var\ folder on the owner of "EMC Avamar backup cluster client for " (can be determined from the Failover Cluster Manager). To enable DEBUG in winclustersvc, check "Additional Info".winclustersvc INFO: VMGroup 'AvamarBackup_' created' winclustersvc DEBUG: winclustersvc DEBUG: winclustersvc INFO: Adding targets to vmgroup 'AvamarBackup_' and owner '####' winclustersvc DEBUG: ===> RctAddVMGroupMember. winclustersvc DEBUG: ===> AddVMGroupMember. winclustersvc DEBUG: WMI Query : 'SELECT * FROM Msvm_VirtualSystemCollection WHERE ElementName="AvamarBackup_"' winclustersvc DEBUG: WMI Query : 'SELECT * FROM Msvm_CollectionManagementService' winclustersvc DEBUG: ===> GetVmObjectbyId winclustersvc DEBUG: WMI Query : 'SELECT * FROM Msvm_ComputerSystem WHERE Name=""' winclustersvc INFO: System.Management.ManagementException: Returned collection empty at EMC.BRS.HypervProxy.Common.WmiUtilities.GetVmObjectbyId(String id, String className, ManagementScope scope) winclustersvc ERROR: No Msvm_ComputerSystem could be found with GUID "", WMI query returned ManagementException ! error message is Returned collection empty winclustersvc INFO: System.Management.ManagementException: Returned collection empty at EMC.BRS.HypervProxy.Common.WmiUtilities.GetVmObjectbyId(String id, String className, ManagementScope scope) at EMC.BRS.HypervProxy.HypervAdvanceBackup.RCTAddVMGroupMember(ManagementScope scope, String groupName, String vmName) winclustersvc ERROR: Exception in Adding VM '' to group 'AvamarBackup_' with error 'Returned collection empty'.To reproduce the issue, in PowerShell (as administrator), run the below command (without angle brackets):Get-Wmiobject -Query "SELECT * FROM Msvm_ComputerSystem WHERE Name=''" -Namespace "root\HypervCluster\v2"The query for "VM_GUID_1" returns ZERO (empty result).For comparison, the query for other VM in the cluster - ‘VM_GUID_2’, which does not have checkpoint issue, works just fine:PS C:\Users\######> Get-Wmiobject -Query "SELECT * FROM Msvm_ComputerSystem WHERE Name=''" -Namespace "root\HypervCluster\v2"snippet:======__GENUS : 2__CLASS : Msvm_ComputerSystem__SUPERCLASS : CIM_ComputerSystem__DYNASTY : CIM_ManagedElement__RELPATH : Msvm_ComputerSystem.CreationClassName="Msvm_ComputerSystem",Name="########"__PROPERTY_COUNT : 45__DERIVATION : {CIM_ComputerSystem, CIM_System, CIM_EnabledLogicalElement, CIM_LogicalElement...}__SERVER : #######__NAMESPACE : root\HypervCluster\v2__PATH : \\#######\root\HypervCluster\v2:Msvm_ComputerSystem.CreationClassName="Ms vm_ComputerSystem",Name="############"AvailableRequestedStates :Caption : Virtual MachineCommunicationStatus :CreationClassName : Msvm_ComputerSystemDedicated :Description : Microsoft Virtual MachineDetailedStatus :ElementName :

Cause

The WMI info for VM in ‘root\HyperVCluster\v2’ is missing.

Resolution

Fix/workaround:Advise the customer to remove the VM in question from the cluster then add it back. The WMI info for VM in ‘root\HyperVCluster\v2’ will be re-created.

Support Cases