Denesh Naidoo (6/18/2013)
The resolution is to restart the app server...then SQL is fine. Once I can get in, checking the error logs...there are no errors of note. The only error I see is "I/O requests taking longer than 15 seconds" around the time the issue was experienced. Each time this happens, the I/O error is for different data files.
Can you check the drive system for any malfunctions? the error messsage is obvious with either Io issue or your IO is not be able to catch large number of transaction,(but in your case, you cant be able to login).
I see connection problem could be from different area. Is this connection failure is intermittent?