The database is 38GB and the backup is set for every day at 12:00am. It is disk backup. Everything was fine but two days it started taking longer time. We have raid 5 in SAN environment. When I check the activity monitor on those two days I have seen that the 'BACKUP DATABASE' process is set to suspended with a huge wait time and the wait type is ASYNC_IO_COMPLETION.
Every day it fininshes in 50 minutes but Monday night and Thursday night it takes 6 hours. I ran the profiler on those days but could not find anything. How do I trouble shoot this problem? Any suggestions?