Our database is currently at 64 Gb and one of our apps started to fail with the following error:
System.Data.SqlClient.SqlException
: Coul
I just ran into the same problem. The reason was that the virtual memory file "pagefile.sys" was located on the same drive as our data files for our databases (D: drive). It had doubled in size and filled the disk but windows wasn't picking it up, i.e. it looked like we had 80 GB free when we actually didn't.
Restarting SQL server didn't help, perhaps defragment would give the OS time to free up the pagefile, but we just rebooted the server and voila, the pagefile had shrunk and everything worked fine.
What is interesting is that during the 30 min we were investigating, windows didn't calculate the size of the pagefile.sys at all (80gb). After restart windows did find the pagefile and included it's size in the total disk usage (now 40gb - which is still too big).