Diagnostic Information; Logs; Fault Log; Error Rate Log - HP 3000 Series Handbook

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Diagnostic Information
The follo;ving paragraphs provide information on the DDS drive internal status logs and
the Extended Sense data returned by the DDS drive in response to a REQUEST SENSE
command.
The method of accessing this information depends on the diagnostic tool you are using. Refer
to the appropriate diagnostic documentation for information on retrieving device information.
Logs
The DDS drive maintains three internal logs: the fault log, the error rate log, and tape log.
Fault Log.
The Fault Log contains information about hardware faults that have occurred since
the log was last cleared. The Fault Log is located in DDS drive controller RAM and is
not
transferred to the tape. The Fault Log is cleared when the DDS drive power is cycled or reset,
or when the CLEAR LOGS command is executed. The Fault Log has a maximum limit of 30
entries and operates on a first-in-first-out (FIFO) basis. The Fault Log entries are organized
by event and time of occurrence.
Error Rate Log.
The Error Rate Log contains information about the types and counts of errors
that have occurred on the tape during the current tape load or since the Error Rate Log was
last cleared. The Error Rate Log is cleared when the DDS drive power is cycled or reset, when
the CLEAR LOGS command is executed, or as an option when initiating an error rate test.
The log is not saved on the tape when the tape is unloaded.
Tape Log. The Tape Log contains information about the number of groups read, written,
and retried for the current tape load and the last (previous) tape load. The Tape Log also
contains the totals since the tape was initialized, including the current load. The Tape Log
cannot be cleared. It is copied to RAM when the tape is loaded, updated in RAM during the
load, then copied back to the tape during the unload sequence. This means that if the drive is
power-cycled with the tape loaded, the current information is lost.
Note
"
If a DDS cassette is write-protected, the drive cannot update the Tape
Log when the cassette is unloaded. Consequently, the Tape Log on a
write-protected tape will not reflect the true usage of the tape.
REQUEST SENSE Data Fields
Table 5-53 shows the data format for the following data fields returned by the drive in
response to a REQUEST SENSE command. Reserved fields always contain zeros.
5-66 Troubleshooting