This is a hardware issue outside of NVBU i.e. problems reading the media and will need to check the NetVault Server Motherboard (not likely though), SCSI/FC Card (if the SCSI Card has RAID on it, then try a non-RAID SCSI Card, as more reliable – Adaptec are good), SCSI/FC Card firmware, SCSI/FC cables, SCSI Terminators, tape library, drive(s), library firmware, drive(s) firmware and media itself.
The tape library drives at the time of the backup could also have had a problem with the Read/Write Head i.e. a hardware issue or was dirty and couldn’t transfer part or all the data correctly during the backup to tape.
In this instance the tape library Firmware version was below the minimum supported version and the tape library also had a hardware issue.
The tape library was replaced to resolve this issue.
Note: Whenever you make any hardware/firmware/cable changes and/or upgrades, then you also have to perform the following steps to make sure that the SCSI Protocol Communication Channel has been re-established (otherwise you will experience media/device/job issues):
a] Make a screenshot of the tape library name and configuration settings, so that the device can be re-added with the same tape library name and configuration settings.
b] Remove the tape library in NetVault Device Management.
c] Reboot the NetVault Server.
d] Re-add the tape library, making sure that the same tape library name and configuration settings are implemented.
Note: Please check the NetVault Backup - Supported VTLs, Libraries, Tape and Optical Drives compatibility guide on the following link to make sure that your tape library/drive are supported and that the library/drive firmware versions are above the minimum supported version too: