Data Backup and Recovery

Hyper-V Nodes dropping off VSS Writer list on Cluster resource owner on 2016 Hyper-V Cluster


Hi all;  where I work we have a  4 node Windows Server 2016 Hyper-V cluster, each with WHU 7.1, SnapDrive 7.1.5 and SnapManager for Hyper-v 2.1.3.  Currently running OnTap 8.2.3P1 what is very soon to be upgraded.


Cluster has three volumes connected with SnapDrive on each node:


  • CSV volume for VM's
  • CSV volume for SnapManager for Hyper-V (SnapInfo)
  • Volume for Disk Witness in Quroum

Intermittently the distributed application consistent backups taken with SnapManager for Hyper-V will start failing and will continually then fail unless I reboot the nodes that appear to be missing from the VSS witters list on the node that owns the cluster where the backups are taken from.


I don't know if this normal or not in regards to not all the nodes appering on the VSS witters list on the node that owns the cluster resource group, but it's what i have recentley noticed.


For example, the below is missing from the "Cluster Shared Volume VSS Writer" section of the VSS Writers list on the Cluster resource owner where the SnapManager backups are taken from untill I reboot VM-Node2.


+ Component "Cluster Shared Volume VSS Writer:\F9894808-30A0-4730-99E8-1F224760E715<CSV>66841cd4-6ded-4f4b-8f17-fd23f8ddc3de:50ccb3b7-9268-49da-994c-64b476c36bd5:VM-Node2</CSV>"
			- Name: F9894808-30A0-4730-99E8-1F224760E715<CSV>66841cd4-6ded-4f4b-8f17-fd23f8ddc3de:50ccb3b7-9268-49da-994c-64b476c36bd5:VM-Node2</CSV>
			- Logical path: 
			- Full path: \F9894808-30A0-4730-99E8-1F224760E715<CSV>66841cd4-6ded-4f4b-8f17-fd23f8ddc3de:50ccb3b7-9268-49da-994c-64b476c36bd5:VM-Node2</CSV>
			- Caption: Offline\LAB-APP01
			- Type: VSS_CT_FILEGROUP [2]
			- Is selectable: TRUE
			- Is top level: TRUE
			- Notify on backup complete: FALSE
			- Paths affected by this component:
				- C:\ClusterStorage\VM_Storage_Cluster\lab-app01\Snapshots
				- C:\ClusterStorage\VM_Storage_Cluster\lab-app01\Snapshots\
				- C:\ClusterStorage\VM_Storage_Cluster\lab-app01\Snapshots\55E46C19-0D34-47C9-9CEB-3293AE0EB4E7
				- C:\ClusterStorage\VM_Storage_Cluster\lab-app01\Snapshots\BD9C2128-3A17-48E2-8B34-4A0FC8CD6C33
				- C:\ClusterStorage\VM_Storage_Cluster\lab-app01\Virtual Hard Disks
				- C:\ClusterStorage\VM_Storage_Cluster\lab-app01\Virtual Hard Disks\
				- C:\ClusterStorage\VM_Storage_Cluster\lab-app01\Virtual Machines\
			- Volumes affected by this component:
                               - \\?\Volume{57705205-5386-4040-a163-7fe707aade75}\ [C:\ClusterStorage\VM_Storage_Cluster\]
			- Component Dependencies:


VM-Node1 is normally the cluster resource owner and thus where the distributed application consistent backups with Snap Manager for Hyper-V are taken from. The above quoted text was a small section taken from VM-Node1 with the "diskshadow" and "list writers"  commands in command prompt.

I have since disabled the automatic balancing of virtual machines under the "Balancer" tab of the cluster proprieties in case that is responsible; I don't know if this option can be enabled or not?

Also no windows updates have yet been installed on any of the nodes of the Windows Server 2016 Hyper-V Cluster if that may also be responsible for the backup issues? In essence what is causing these VSS related backup issues and how can they be properly resolved?  


I have tried restarting the SnapManager for Hyper-V Web Service and the VSS Service of the nodes in the cluster to no avail; whilst rebooting nodes sequentially that are missing from the VSS writers on the owner node works, it is anything but an ideal solution nor should that even be required!

Regards: Elliott.