This has been driving me batty for last month. Server is otherwise fine, no event log messages, but all file shares simply stop responding. We have dug into this fairly deeply, and the best guess I can see is a significant delay in authentication is causing a timeout on service access. We sometimes get different loss of access depending on whether its a XP or Win7/8 client. A server reboot is the only thing that fixes it. It affects DFS and normal shares, which means our Group policy stops as well as our simple shared company folder.
We are about to do a migration to 2012R2 in hope it fixes the issue, after that it is back to 2008 R2...
Would love for ANY clue as to what is causing this.
(on that note we are VMWare hosted 2012 as well....)
