Dell PowerVault ML6000, Maintenance Manual

Page: 236 / 494

218 Troubleshooting the Tape Library
T021
T021 - Drive Sled Communication Failure
Description GUI Description: The library lost communication with a drive sled.
Explanation: The library had been communicating with a drive sled that is
configured for use in a partition. When the library detects loss of
communication with a drive that is online, the library robot attempts to scan
the barcode label on the drive. If the label is read and communication is not
present, the RAS ticket gets posted based on the fact that the drive is
physically present but no communication is occurring. If the label is not read,
the drive is assumed to be physically removed and therefore communication
should not be expected.
This ticket is specifically NOT caused in two common scenarios:
• Physical removal of a drive if the drive is not assigned to a partition.
• Complete physical removal of a drive if it is turned offline via the library
operator interface.
Detection Scenarios Routine polling of the sled conveyed the drive communication issue.
Root Causes • Drive sled is physically removed/unplugged (intentional or not properly
secured with its thumbscrews) while drive is online.
• Various hardware failures occurred on the drive sled controller or
communication path from the drive bay to the drive sled controller.
• Various hardware failures occurred in the library communication path to the
drive sled.
• A module terminator or module-to-module cable is damaged with bent or
broken pins.
Service Resolution
Steps 1 Perform DR029 - Resolve Drive Sled Communication Loss on page 380.
2 Use the Details option in the RAS ticket to identify which tape drive is
generating the RAS ticket. If possible, check the front of the tape drive for
error indications. Check the suspect drive sled and reseat it.
3 Inspect the module terminators and module-to-module cables for loose
connectors or damage (bent or broken pins). If damaged, replace the part.
Reseat the terminators and cables.
4 Finally, ensure that power is properly being received by the tape drive (green
LED on the front of the drive).
5 If using library firmware 400G, run an IVT - Drive test from the Library
Tests menu on the operator panel. Clear the RAS ticket and retry the
original operation.
Note: IVT is optimized for library firmware versions 520G and above and
libraries built after July 1, 2008 (serial numbers with last four digits 8602 and
above).
• If your library was built on or before July 1, 2008, and you are running
firmware version 520G or later, you will not be able to run the IVT test,
even though the selection is available.
• If your library was built on or before July 1, 2008, and you are running
firmware version 500G or earlier, you can run the test, but it is not
recommended because it may produce erroneous results.