Job fails with media error then Unexpected error writing to media when backing up to physical tap (4046608)

Date: 15-06-2011

Affected Product:Netvault Backup

OS Version: Windows 2003 R2 Standard and Enterprise 64bit
Plugin version: N/A
Application version: N/A

Description: job fails with 'media error' then 'Unexpected error writing to media' when backing up to physical tape.

Symptoms:
Job fails with 'media error' then 'Unexpected error writing to media' when backing up to physical tape. The tape is then marked as read-only:
Error 2011/06/15 03:11:23 1154 Media snapsi2 Error transferring data to Mid 'snapsi2 22 Nov 15:02-1', marked read only
The full errors and trace context will be something like:
Error 2011/06/15 03:11:23 1154 Media snapci2 snapci2 8-0.4.0 (HP Ultrium 4-SCSI): had media error

SCSI 25 0 21123 CMD WRITE [ 0a 01 00 00 01 00 ]
SCSI 17 0 21123 CMD SENSE KEY 'ABORTED COMMAND ' [b] - ASC 47 ASCQ 01
SCSI 18 0 21123 CMD SENSE INFO '<UNKNOWN>'
TAPESCSI 85 0 21123 Unexpected error writing to media
MEDWRITE 183 1 21123 Device write data out: FAILED

Error 2011/06/15 03:11:23 1154 Media snapsi2 Error transferring data to Mid 'snapsi2 22 Nov 15:02-1', marked read only

DEVMGR 272 0 21123 lPosition = -1
DEVMGR 273 0 21123 bHardwareError = TRUE
DEVMGR 274 0 21123 bAborted = FALSE
DEVMGR 275 0 21123 Generate Transfer Info (END)
This will happen for all media and these tapes will be marked read only after an attempt has been made to write to them. SCSI errors or other hw errors may be reported in the operating system's SYSLOG.

This will almost certainly be a hardware error either with the SCSI card (though one would expect to see 'command failed, re-initializing driver'™ messages in the log.) The problem is probably not due to drive order as there is no message that the lib cannot move a tape to/from a slot.
Contact the Hardware supplier as this will be a problem with the drive or library.