I have a few people outside the network who connect to our network via VPN (sonicwall SSL VPN). There were few if any problems until I switched file servers from server 2003 to server 2012. Now all the sudden I have horrible file locking and saving issues. Some errors that are occurring very often but not all the time:
When a file is opened, they get the error: " cannot be accessed. The file may be corrupted, located on a server that is not responding, or read only. (note the ") if they hit 'retry' a few times the spreadsheet appears to open
When a file is saved, they get the error: "[file in question] is currently in use. Try again later"
Most times they can retry the save a few times, and eventually it will actually save. Other times they get that error every time until they give up. Local users are not reporting any problems with saving and opening files. Overall performance over the VPNs has also dropped dramatically. It can literally take 2 minutes to open a 70k file.
I have verified that the user I am testing with has a 100 meg pipe. Throughput doesn't seem to be an issue. Everything started happening as soon as I started using server 2012 as a file server. I have verified that nobody has these files open during my tests. I've noticed that looking at the file locks, sometimes I have a read-write lock with a user of [disconnected] for some of these files.
Can anybody give me a clue as to where to start troubleshooting this issue?