SNC 5100
58 SCSI Channel MAP
6-00020-02
SCSI Loop Back Test
Caution
Before performing diagnostics, all FC and SCSI cables must be
disconnected from the SNC 5100. Before changing any SCSI
cables, all I/O to the SNC 5100 must be stopped and the SNC 5100
must be turned off. Do not perform SCSI loop back tests on SCSI
channels that are attached to SCSI target devices. If you do this, you
will corrupt the data on the device.
Step 1. If the SNC 5100’s command prompt on the terminal is not
diagmode >, enter the diagBoot command on the service terminal
For more information, see “Entering Diagnostic Mode” on
page 187.
Step 2. Power down the SNC 5100.
Step 3. In addition to the suspect SCSI channel, choose one of the other
SCSI channels to use for the loop back test.
Step 4. Label and remove those cables.
Step 5. Connect a short SCSI loopback test cable to those two SCSI
channels.
Step 6. Power on the system.
Step 7. Wait for the SNC 5100 to finish booting.
Step 8. Enter the scsiChannelTest(1,2) command. The following
example shows a loop back test on SCSI channels 1 and 2.
Example:
diagmode > scsiChannelTest (1,2)
SCSI-1 -> SCSI-2 [##########] 10 iterations PASSED
SCSI-2 -> SCSI-1 [##########] 10 iterations PASSED
value=0=0x0
Step 9. If the SNC 5100 returns a PASSED status, go to "Testing SCSI
Cables".