A job fails with a job log message saying "Backup Killed", such as seen below:
Error 2012/05/24 11:23:32 2894 Data Plugin ClientName Backup Killed
The "Backup Killed" message normally means that the job was waiting for media for longer than the "Media Request Timout" setting specified in the job's Target tab.
Ensure that when the job runs, sufficient available media is available at the time that the job runs.
Optionally, the setting for "Media Request Timout" setting can be increased.