Marking volumes full is not related to what is being backed up, but rather the fact that you get information from drive/media that end of tape has been reached. Another factor contributing marking tapes as full are SCSI bus resets in your environment or other kinds of I/O errors. I would suggest to check the logs as they should contain more information to what has happened before volume has been marked full.

I have experienced the smae problem using Dell LTO drives at several sites. Only STSTEM STATE: does it. If using Dell LTO drives, reduce the parallelism to 1. This would get resolved.

Otherwise, check logs for SCSI reset errors as Crvelin mentioned. May be you can try and disable CDI to test.