IBM TS2900 Setup, Operator, And Service Manual page 222

To correct a problem you noticed in the errpt report, determine the type of error by
using the examples that follow:
• For library errors [Resource Name = smcn (for example, smc0) and Resource Type
• For drive errors [Resource Name = rmtn (for example, rmt0) and Resource Type =
SCSI Sense Data Definition
The following is an example of a tape drive communication failure while attached to
an Open Systems host through a SAS 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 ssss 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
Detail Data
aabb xxxx ccdd eeee eeee eeee eeee eeee ffgg hhxx ssss ssss ssss 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 a System p 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.
The ASC/ASCQ points to a "Mechanical Positioning Error" while attempting a
"Move Medium" command ("A5"). For more information about Sense Data, refer to
the IBM TotalStorage LTO Ultrium Tape Drive SCSI Reference.
E-2
TS2900 Tape Autoloader Setup, Operator, and Service Guide
= 3572-TL]), see "SCSI Sense Data Definition" on page E-2 and the SCSI sense data
in "Library Sense Data" on page D-2.
LTO], see "SCSI Sense Data Definition" on page E-2 and locate the SCSI sense data
in "Tape Drive Sense Data" on page D-3.
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.