The tape drive may go offline on the Backup Exec Devices tab intermittently when backup jobs run. Stopping and restarting the Backup Exec Services, or rebooting the server may bring the device back online, but the device goes offline at some point during another backup.
Systems exhibiting this behavior should be checked for hardware and specifically SCSI related issues:
-If a driver update is available for tape device or controller, try installing it.
-If a firmware update is available for tape device or controller, try installing it.
-Try the drive on another controller card.
-Try the controller card(s) on another PCI slot on the motherboard.
-Try the drive or controller card on another system.
-Try removing some devices from an overloaded card by adding an extra controller to share the load.
-Do not use RAID or embedded controllers.
See Veritas TechNote ID: 248089.
I got this event along with Event ID 11 from source BENCHMRK and Event ID 15 from source powerfil when the power supply failed on our Dell PV122T tape drive.
See the comments for event id 15 for scsi driver.