Troubleshooting Tape Library Hardware Problems in NetWorker

• Unable to use library reliably for NetWorker backup
• Receiving ASC / ASCQ / SCSI SENSE errors or messages in system or application logs
• Unable to detect presence of library from intended robot control host
• Inability for library to move to Ready state in NetWorker
• Sporadic or consistent errors performing specific or random library operations

If the library was working previously and suddenly encounters an issue, consider possible changes that may be impeding operations:

• Robot, switch or adapter firmware, driver or configuration change
• Addition, replacement or removal of tape hardware, tape cartridges or other library components
• Change of NetWorker software version, Operating System patches
• Any hardware event such as power loss or reboot of any component in the data path
• Any activities involving opening the library door

To identify a hardware issue in a tape library, operations must be tested at their most devolved levels. In order to isolate the problem, SCSI-based transport is removed from the datapath to test pure library functions.

Keep in mind that several library components may appear functional. A hidden component failure can still prevent the library from operating properly for host applications. For example, a robot may move volumes correctly, but its internal logic may misidentify drive serial numbers or lose track of element locations. A command may succeed through the web interface, yet the library may fail to log in to the SAN switch. This can indicate a target‑side GBIC or backplane problem.

Run the following basic tests to confirm which functions work over each interface. Use these techniques to attempt recovery before engaging the library vendor.

Library hardware - LCD panel

Begin troubleshooting as locally to the robot as possible - for most library Administrators, this means the display panel on the front of the library unit. Starting at this point helps to exclude SCSI transport or Ethernet or web GUI-specific issues.

• Check for errors - typically, an obvious fault in the storage is shown as an error code either in the main window, or in an 'Alerts' or 'Errors' submenu. Any problems found here should be referred immediately to the vendor (failure to do so may exacerbate damage).
• Test basic operations in the user interface (the same as those tested in LCD display)
  • Move a tape cartridge from slot to drive, drive to drive, drive to slot, and slot to slot.
  • If an import and export slot or magazine exists, test the same functions with them, using all combinations of source and destination, per above.
  • Test exporting and importing tape cartridges physically from and to the library.
  • Test library initialization, inventory, and reset functions if available.
  • If a tape cartridge cannot be removed from a robotic hand, drive, or slot - you must manually remove it from the library before proceeding.
• Confirm data presentation:
  • Ensure that tape cartridge locations, barcodes, and drive statuses are correct.
  • Check which features of the library, if any, are enabled and confirm effects.
• Virtual libraries do not have LCDs, but their health can be checked at the most primitive level at the command line of the storage device that virtualizes them; like physical libraries, vendor assistance, with their specialist tools and knowledge, may be required.
  • For Data Domain library testing, see Troubleshooting VTL Target Visibility Issues
  • For Dell Disk Library testing, see Troubleshooting an EDL server or Troubleshooting Backup Application (BSP) to EDL communication issues

Library Intelligence - Web user interface

The next level of testing that is commonly available is the web interface that serves as the library's user interface. This interface is common to both Physical Tape Libraries and Virtual Tape Libraries, and seeks to provide comprehensive access to the library and its functions.

This testing method bypasses the normal SCSI datapath, including the host Host Bus Adapter (HBA), switches, and target ports. It sends SCSI commands directly from the embedded web server to the robot. As such, it may not be a true representation of actual problems being encountered in standard use.

• As above - check the user interface for alerts or error queues or indications within the interface. Again, library-reported problems should be referred immediately to the vendor.
• Test basic operations in the user interface as was done in the LCD, if possible
• Confirm data in the user interface as was done in the LCD, including host connectivity, barcode locations, drive serial numbers, and any other relevant data

Library Service - Vendor:

If the library shows that no faults but hardware issues appear in the switch, transport, or host layers, contact the vendor. They can troubleshoot using specialized tools and knowledge. Before this is done:

• Power down the library entirely and leave unpowered (and ideally, unplugged) for 5 minutes. Large devices like tape libraries need time for capacitors to discharge and potentially clear malfunction conditions.
• Arrange to upgrade the firmware for the robot and the drives (often this requires vendor assistance anyway). For hardware problems, it is best to be on current code.
• Ensure any bad cables, or drives are removed from the library. It is not uncommon for one malfunctioning component to affect others - swap any suspected components to test, if possible, to isolate the problem further.