Since implementing CommVault Simpana, I have been receiving almost daily warnings of the following error (Event ID 5120) in my System log:
Cluster Shared Volume 'CSV2' ('CSV2') has entered a paused state because of '(c0000435)'. All I/O will temporarily be queued until a path to the volume is reestablished.
After some thorough investigation resolved a bunch of issues with cluster communication, this error continued to appear.
I was finally able to resolve this from happening by unregistering the EqualLogic VSS Hardware Provider, using this command:
"C:\Program Files\EqualLogic\bin\eqlvss" /unregserver
The strange thing is, I had specifically set CommVault to use the CSV Shadow Copy Provider, with the setting “VSSProviders” on my clients. Despite this, there must have still been some VSS ties to the EQL provider.