IBM T400F manual Resolving Problems Reported by the Server, Fixing SCSI Bus Errors

Resolving Problems Reported by the Server

The procedure for fixing SCSI bus or Fibre Channel errors varies, depending on whether the error is consistent or intermittent, and whether your configuration contains single or multiple Ultrium 2 Tape Drives. The sections that follow describe how to fix each type of error.

Fixing SCSI Bus Errors

Note: If you are using a Storage Area Network (SAN) Data Gateway to convert a drive with a SCSI interface to a Fibre Channel interface, ensure that the problem is occurring between the SAN Data Gateway and the drive by running the SCSI wrap test on the drive and running the SCSI loopback test on the SAN Data Gateway. (To run the SCSI wrap test, see Function Code 6 in Table 9 on page 36; to run the SCSI loopback test, refer to the section about that test in the IBM Storage Area Network Gateway Module Setup, Operator, and Service Guide.) If you are using a Fibre Channel drive and are having problems, see “Fixing Fibre Channel Errors” on page 79.

Fixing a Consistent Error with a Single Drive on a SCSI Bus

1.Ensure that the power is on to the Ultrium 2 Tape Drive.

2.Ensure that the tape drive’s SCSI address is the same as the SCSI address assigned by the server.

3.Run the SCSI wrap test (see Function Code 6 in Table 9 on page 36).

vIf the test runs successfully, replace the SCSI terminator first, then the SCSI cable and the interposer (if installed). Repeat the operation that caused the error. If you replaced the SCSI terminator or SCSI cable and the problem persists, the fault is with the server’s hardware or software. To isolate the cause of the failure, refer to the server’s service documentation.

vIf the test fails, replace the tape drive (see “Removing a SCSI Tape Drive from an Enclosure” on page 83).

Fixing a Consistent Error with Multiple Drives on a SCSI Bus

When a consistent error occurs in a configuration that has multiple tape drives on the SCSI bus, you must determine if the problem exists with more than one tape drive. If the problem is with all of the devices on the SCSI bus, the bus is stuck in a SCSI phase and cannot change to another phase or the SCSI cable from the server to the first device is defective.

1.Ensure that the SCSI cable from the server to the first device is connected.

2.Disconnect all but the first tape drive on the SCSI bus. Move the terminator to the first SCSI device.

3.Run a device driver utility (such as IBM’s ntutil or tapeutil) to determine whether the error will occur.

v If the error occurs, run the SCSI wrap test on the first tape drive (see Function Code 6 in Table 9 on page 36).

–If the test runs successfully, replace the SCSI terminator first, then the SCSI cable and the interposer (if installed) to the first tape drive. Repeat the operation that caused the error. If you replaced the SCSI terminator or SCSI cable and the problem persists, the fault is with the server’s hardware or software. To isolate the cause of the failure, refer to the server’s service documentation.

–If the test fails, replace the tape drive (see “Removing a SCSI Tape Drive from an Enclosure” on page 83).

Chapter 6. Resolving Problems 77