On a Windows Server 2012 R2 Hyper-V cluster I had an issue whereby backups were failing with VSS errors.
When running VSSAdmin List Writers I received the response: “Waiting for responses. These may be delayed if a shadow copy is being prepared.”
In order to resolve this I restarted the COM+ Event System service. Following this VSSAdmin List Writers failed to return anything.
When restarting the COM+ Event System service there are a number of dependant services. I noticed that the COM+ System Application service hadn’t automatically restarted. I started the service, then restarted the services below. Following this VSSAdmin List Writers returned the expected list of writers.
- EqualLogic VSS Requestor – Specific to my use of EqualLogic storage
- EqualLogic VSS Service – Specific to my use of EqualLogic storage
- Hyper-V Virtual Machine Management
- Microsoft Software Shadow Copy Provider
- Volume Shadow Copy
Richard Skinner 
Hi Richard,
thanks for your help, thats exactly what we encountered and we solved it with restarting the services you also noticed. But the question is: Whats the real issue behind the failure, because after every restart of the pc, the vssadmin list writers command is delayed and backup does not work. I will go on with that workaround but I am trying to find the solution that lasts even after a restart.
Best Regards
Marc
Nice !!!