Explanation: When a job is run on a media server installed with pre NetBackup 6.0 software, there are some situations where the job starts, but media is not available for the job. In this case, the master server stops using that storage unit for a period of time (12 hours), and returns this error for jobs requested the storage unit.
Recommended Action: Make sure media is available for the storage unit. Add media if necessary. If media is available, wait 12 hours until the storage unit can be used again. To make the storage unit immediately usable, run the following command on the master server to release: