Scsi Sense Data Definition; Scsi Sense Data - Library Error - IBM TS3100 Setup, Operator, And Service Manual

v For Fibre Channel adapter errors (not Fibre Channel bus errors), use the maintenance package for the
host.
Note: See Appendix D, "Sense data," on page 297 for further details on sense data.

SCSI sense data definition

Following is an example of a tape drive communication failure while attached to an Open Systems host
through a fibre channel link, using SCSI protocol. When the host detected the failure, it built the
following SCSI Sense Data record. An explanation of the SCSI Sense Data breakout in this example
follows.
SENSE DATA
aabb xxxx ccdd eeee eeee eeee eeee eeee ffgg hhxx ssss ssss
0600 0000 1200 0000 0000 0000 0000 0000 0200 0300 0000 0000 0000 0000 0000 0000
0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000
0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000
0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000
0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000
Note: The bold area above represents the SCSI Sense Data presented by the host. The regular font data (in this case
many bytes of 'zero'), designated by 'ssss' would normally contain device sense data, but with the kind of failure in
this example (COMMAND TIMEOUT), the host could not collect valid device sense data, so zeros are the result and
should be ignored. If the host had been able to collect valid sense data from the drive, the first byte 'ss' would be
'70', '71', 'F0' or 'F1', and valid device sense data would be listed.
DETAIL DATA
aabb xxxx ccdd eeee eeee eeee eeee eeee ffgg hhxx ssss ssss
aa Length of the Command Descriptor Block (CDB) sent by the host. In this case, '06' bytes.
bb SCSI target address. In this example, SCSI address '00'.
xx Unused or reserved
cc Start of CDB, cc is the operation code (byte 0). In this case, '12' which was an "Inquiry".

SCSI sense data - library error

The following example of SCSI Sense Data was received from an RS/6000 Open System host and shows a
Tape Drive Failure and what the sense data would look like. Unlike the previous situation with "SCSI
sense data definition", this data contains valid sense data as defined by the hex '70' in the first sense byte
position. Therefore, instead of all zeros as in the previous example, we have valid data to rely on. While
the data shows that this is a TAPE_ERR2, it could also be caused by a library failure. As described, the
resource name is smc0 indicating a library error. The ASC/ASCQ points to a "Mechanical Positioning
Error" while attempting a Move Medium command ('A5'). For information about sense data, consult your
IBM TS3100 Tape Library and TS3200 Tape Library SCSI Reference.
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IBM TS3100 Tape Library and TS3200 Tape Library: Setup, Operator, and Service Guide Machine Type 3573
ssss ssss ssss ....
ssss ssss ssss ....