Resolving errors with Fibre Channel communications

Refer to a list of actions to identify and resolve communication errors with Fibre Channel devices.

1. Ensure that all Fibre Channel cables from the host to the library are securely connected at both ends.
2. If multiple Fibre Channel drives exist on a single loop (as when multiple drives are connected to a hub), ensure that each device on the loop has a unique loop ID.
3. Ensure that all Fibre Channel host adapters are supported (for a list of supported adapters, refer to http://www.ibm.com/servers/storage/tape/drives. Under the appropriate tape drive, select Product details. Then, select Host bus adapter. Or, contact your IBM® sales representative).
4. Ensure that the appropriate levels of device driver are installed and that any other prerequisites are satisfied.
5. If you are connecting through a storage area network (SAN) Data Gateway, ensure that the gateway has the appropriate level of firmware (see note at the end of table).
6. If you have 4 Gb Fibre Channel backend switches (FC 4872 or 4873) or 8 Gb Fibre Channel backend switches (FC 4875 or 4877) installed on an L23 or D23 frame, contact your service representative. The TS7700 Virtualization Engine or 3592-C07 detects any problem with the Fibre Channel switches and generates a Call Home.
7. If the maximum number of cartridges is more than 6 887 for the logical library, or if the logical library has shuttle stations that are assigned, ensure that the logical library uses LTO Ultrium 4, 3592 E05, or later tape drives as control path drives. To support more than 6 887 cartridges, Ultrium 4 control path drives require a minimum code level of 97F0. For logical libraries with shuttle stations, Ultrium 4 control path drives require a minimum code level of A480. Ultrium 5 control path drives require a minimum code level of B170. Perform the following steps to ensure that you have the correct drives and code levels:
   1. Display the control paths using the Drive Assignment page on the Tape Library Specialist web interface . If an older generation tape drive is used as a control path, proceed with the next step.
   2. Follow the instructions in Enabling or disabling a control path in a logical library to disable the older generation tape drive and enable the appropriate drive as the control path.
   3. Reconfigure the host to pick up the device again. Refer to your device driver documentation for additional instructions.
8. Some Fibre Channel devices (such as the SAN Data Gateway, or routers and switches) provide diagnostic routines that show all of the devices that are attached to them. Refer to the device documentation for details about the routines. If a Fibre Channel device that is positioned between the host and the library can see the library's devices, the problem is probably between the Fibre Channel device and the host.
9. Ensure that the host is configured with the correct World Wide Node Name or worldwide port name.
10. Refer to the problem determination information in the documentation for the device driver that you are using. If you are using the IBM Ultrium Device Drivers, refer to IBM Tape Device Drivers Installation and User's Guide. Ensure that the device driver is loaded and that it can communicate with the tape drives:
    1. If the device driver is not loaded, install it.
    2. If the device driver is loaded but cannot communicate with the tape drives, call your IBM service representative.
    3. If the device driver is loaded and can communicate with the tape drives, but the application software cannot communicate with the tape drives, contact the provider of your application software for assistance.
11. Current Fibre Channel components support various Fibre Channel speeds. Possible speeds are 1 Gb/s, 2 Gb/s, 4 Gb/s, 8 Gb/s, and 16 Gb/s. The Fibre Channel speeds for any given port support the native speed of the port and two additional speeds (n-1 and n-2). Refer to the machine configuration and ensure that all drives, switches, and host bus adapters use compatible speed settings.
12. For a 3592 tape drive, open the rear door of the library, locate the affected drive, and observe the status LEDs on the back of the drive canister. The LEDs have the following meaning:
    • Blank: no light is detected at the drive's Fibre Channel port. This indicates one of the following conditions:
      • A Fibre Channel cable is unplugged at the drive or at the nearest Fibre Channel device (host bus adapter, switch, or hub).
      • A Fibre Channel cable is broken between the drive and the nearest Fibre Channel device (host bus adapter, switch, or hub).
      • The drive or the nearest Fibre Channel device (host bus adapter, switch, or hub) is powered off or has a hardware problem.
    • Blinking Yellow: Fibre Channel connections between the drive and the Fibre Channel device to which it is connected (host bus adapter, switch, or hub) are good, but communication has not been established.
    • Blinking Green: Fibre Channel connections are good and data is being transferred.
    • Green (not blinking): Fibre Channel connections are good, but no data is being transferred. Note that the Fibre Channel wrap plug may be installed or that the drive may be offline (in maintenance mode).
13. For an LTO tape drive, open the rear door of the library, locate the affected drive, and observe the status LEDs on the back of the drive canister. The LEDs have the following meaning:
    • Blank: no light is detected at the drive's Fibre Channel port. This indicates one of the following conditions:
      • A Fibre Channel cable is unplugged at the drive or at the nearest Fibre Channel device (host bus adapter, switch, or hub).
      • A Fibre Channel cable is broken between the drive and the nearest Fibre Channel device (host bus adapter, switch, or hub).
      • The drive or the nearest Fibre Channel device (host bus adapter, switch, or hub) is powered off or has a hardware problem.
    • Yellow: Fibre Channel connections between the drive and the Fibre Channel device to which it is connected (host bus adapter, switch, or hub) are good, but communication has not been established.
    • Green: Fibre Channel connections are good and communication has been established.