It could be any number of reasons. The reason will probably be shows in the ERRORLOG.
It could be that the disk you are backing up to is full.
It could be that the network share you are backing up to was rebooted.
If backing up to a network share there could have been a network problem.
More information will be needed to give you a more specific answer.
Last Wiki Answer Submitted: August 6, 2008 7:44 pm by Denny Cherry64,520 pts.