DEC 4000 AXP Service Manual page 85

POST is also used to handle two types of error conditions in the drive:
• Controller errors are caused by the hardware associated with the controller
function of the drive module. A controller error is fatal to the operation of the
drive, since the controller cannot establish a logical connection to the host.
The red Fault LED comes on. If this occurs, replace the drive module.
• Drive errors are caused by the hardware associated with the drive control
function of the drive module. These errors are not fatal to the drive, since
the drive can establish a logical connection and report the error to the host.
Both LEDs go out for about 1 second, then the red Fault LED comes on. In
this case, run either DRVTST, DRVEXR, or PARAMS via the
command, as described in the drive's service documentation, to determine the
error code.
Three configuration errors are often the cause of drive errors:
• More than one node with the same bus node ID number
• Identical node names
• Identical MSCP unit numbers
The first error cannot be detected by software. Use the
(Section 6.2) to display the second and third types of errors. This command
displays each device along with such information as bus node ID, unit number,
and node name.
If the device is connected to the front panel of the storage compartment, you
must install a bus node ID plug in the corresponding socket on the front panel. If
the device is not connected to the front panel, it reads the bus node ID from the
three-switch DIP switch on the side of the drive.
DSSI storage devices contain the following local programs:
DIRECT A directory, in DUP-specified format, of available local programs
DRVTST A comprehensive drive functionality verification test
DRVEXR A utility that exercises the device
HISTRY A utility that saves information retained by the drive, including the
internal error log
ERASE A utility that erases all user data from the disk
VERIFY A utility that is used to determine the amount of ''margin'' remaining in
on-disk structures
DKUTIL A utility that displays disk structures and disk data
PARAMS A utility that allows you to look at or change drive status, history,
parameters, and the internal error log
set host -dup
command
show device
Running System Diagnostics 3–23