Why do our CommVault tapes stop writing before they are full? We get a message that there is no media. When I check the tapes, there is plenty of valid data space and the tapes are not marked full.
There are a few situations where this condition can be encountered. However, without more details about the actual error and hardware configuration, it is difficult to pinpoint exactly the source of the problem. Below are a few suggestions:
Sometime the tape drive can encounter a media error that is interpreted by the device as an EOT (end of tape) signal. This leads the device to mark the tape as full and stop writing. This error condition does not typically occur with all media in a library making it easy to diagnose but hard to predict. If this is your case, this could be the starting point for troubleshooting.
Check the "Appendable" and "Use Appendable Media for (n) Days option" from the Media tab of the library properties; the number of days might be set lower than it takes you to fill a tape.
A job option which has the Start New Media option enabled, will not use appendable media.
Synthetic full backups will not use appendable media.