DS8000 Service Documentation Version 7.5

MAP5300 Fibre Channel link fault

Link incidents are problems that are not automatically detected, isolated and reported by any one single node on the optical link. They occur on an interface and might cause multiple nodes to detect different types of link incidents. Each node detecting and reporting a link incident will generate its own link incident.

Before you begin

Note: Customer disruption may occur if microcode and power boundaries are not in the proper conditions for this service action. Verify that you start all service activities in Start here.

About this task

Fault isolation of link incidents is solved by the combined use of product and system documentation:
  • Fiber Optic Links (ESCON®, FICON®, Coupling Links & Open System Adapters)
Related tasks:
How to start the service information center

Fiber optic cable handling precautions

Before you begin

CAUTION:
Do not look into the end of a fiber optic cable or into a fiber optic receptacle. Eye injury can result. To verify the continuity of a fiber optic cable, use an optical light source and a power meter. Although shining light into one end and looking into the other end of a disconnected optical fiber to verify the continuity of optic fibers may not injure the eye, this procedure is potentially dangerous. Therefore, verifying the continuity of optical fibers by shining light into one end and looking into the other end is not recommended. (1061)
Note: This notice is translated into selected languages. See IBM® Systems Safety NoticesG229-9054-xx.

About this task

Fiber optic cables are easily damaged from fiber breakage. The cable connectors must be clean to perform correctly. Observe the following precautions to prevent damage when you handle fiber optic cables.
  • Save all the plastic connector covers for later use. These covers can be used to protect the link cable connectors when you remove the storage facility host adapter card or when you store the cables.
  • Do not remove the protective cover plugs from the connector ends until you are ready to insert the connector into a port. You might have to remove the cover to feed the cable through the tailgate.
  • Before you insert the connector into a port, ensure that you clean the connector end faces. Use the fiber optic cleaning procedure specified in the fiber optic connector cleaning kit (New P/N 46G6844 or Old P/N 545321).
  • Do not pull on the connector.
  • Do not bend the cable to a radius smaller than 12mm (0.5 in).

MAP5300 Section-1

About this task

Note: Link errors (including "BER Exceeded"), when detected by the DS8000 host adapter, are usually caused by something external to the DS8000. The possible causes include the:
  • Optical cabling
  • Fibre Channel switch (if a switch is used)
  • System at the opposite end of the link (if directly attached, without a switch)

Procedure

  1. Display serviceable events that need repair. See MAP1210 Displaying and repairing a serviceable event.

    Is there a serviceable event for the host adapter connected to the failing link?

    • Yes, go to the next step.
    • No, go to step 3.
  2. Is the SRC defined as a BER Exceeded (bit error rate exceeded)?
  3. Is the Fibre Channel cable properly connected to host adapter port?
    • Yes, go to the next step.
    • No, connect the cable, exit this MAP and have the customer attempt to use the link. If the problem still persists, go to the next step.
  4. Run the Wrap test to determine if the host adapter card or port is failing.
    Note: A Fibre Channel wrap plug (IBM P/N 12R9314 or equivalent) is required for this test. The test procedure prompts you to insert the plug.
    1. At the management console, from the navigation area, click Storage Facility Management > storage facility.
    2. From the bottom Task area, click Service Utilities > Manage FRUs....
    3. Click Show I/O Enclosures.
    4. Select the I/O enclosure location and click Show Host Adapters.
    5. Select the host adapter and click Perform Wrap Test.

    Did the test run successfully?

    • Yes, go to step 6.
    • No, continue at the next step.
  5. Replace the host adapter (Fibre Channel host card).

    Is the host adapter listed in the serviceable event FRU list?

  6. Have the customer attempt to use the link. Could the customer use the link without further errors?
    • Yes, exit this procedure.
    • No, contact your next level of support.
    The problem appears to be external to the DS8000. Possible causes include:
    • Dirty or damaged Fibre Channel cables
    • Faulty port or adapter at the opposite end of the link
    • Faulty Fibre Channel connections
    • Incorrect Fibre Channel cable grade for the affected link speed
    This troubleshooting is outside the scope of DS8000 maintenance and is the responsibility of the organization supporting the customer's SAN or system/switch attached to the suspect/failing link on this DS8000.