Now I have a better view and I can see that one other cluster have the described problem.
With VMM you can get the message if you try to move, start up a VM:
VMM cannot complete the WMI operation on the server (hyper-v-03.contoso.com) because of an error: [MSCluster_Resource.Name="SCVMM SOF-Prev-02"]
The requested operation can not be completed because a resource has locked status (0x1748)
Failover Cluster Manager will say “The resource $VM is locked.”
From roughly around 70 VMs almost a third can’t be moved, started up or something else.
Really painful is the fact that you can’t do anything with the Hyper-V Host itself.
Trying to get ’em in paused mode for example.
Dynamic Optimizing is getting crazy as well. 😉
Applying the Hotfix seems to be working.
I’m not really sure at the moment about some problems I’m experiencing.
But I have the descibed, a similiar or remotly related problem with 2 fully different Hyper-V Clusters where DPM starts backup but then they hang for hours without time outs. I could see that some VMs still locked trough backup which is really painful because of lacking VMM or general Hyper-V support.
No migration and changes were possible.
Hyper-V virtual machine backup leaves the VM in a locked state – Microsoft Support
One of these clusters is backed up through a small (100 Mbit) pipe to another site… roughly around 5 to 10 small VMs every night.
The other cluster has an amount of 50 – 60 but 10GBit.
I tried to reduce the parallel jobs to 2 and later to 1* but at the end it was helpful to stop and recreate the protection groups.
* registry key – max allowed parallel backup
DPM triggers 3 jobs at a time to any node by default. This per node number can be changed by changing the registry key “Microsoft Hyper-V” (which is a DWORD value and set the appropriate value) located at “HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft Data Protection Manager\2.0\Configuration\MaxAllowedParallelBackups”. Also, a node by default configured to do 8 backup jobs at any given time. This means that if there is a 64 node cluster protected by 5 DPM servers, each node can still honor 8 job parallel requests in total that can come from all or some of DPM servers. This value can be changed by following steps discussed @ the end of the blog article located here.
After checking every detail and running through logs it feels like …