HP Q153090901, Техническое справочное руководство

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SCSI features
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The following additional commands are supported for CD-ROM mode:
For implementation details on these commands, see Chapter 3, “Commands—introduction” and
Chapter 4, “Commands” .
SCSI features
Design approach
The features supported by the drive are based on standards, both official and de facto. The drive is
fully compliant with the current SCSI standards: SPC3, SSC2, SAM2, and the relevant transport
protocol (e.g. SPI4 for the parallel SCSI drive). All mandatory commands and features are
supported, as well as some that are optional. In addition, some features from older standards are
still supported for backwards compatibility.
Power-on
The drive will respond to
INQUIRY
,
TEST UNIT READY
,
REPORT LUNS
and
REQUEST SENSE
commands
within 250 ms of power on. The first command received from an initiator (other than
INQUIRY
and
REQUEST SENSE
) will result in
CHECK CONDITION
status, with
UNIT ATTENTION
sense data reported
for the power on. Once the drive has completed its self-test and set-up procedures, it will attempt
to reload any tape that is already present in the drive. It may take some time to recover the tape,
especially if it was positioned near EOM when power was cycled. During tape recovery, medium
access commands will result in a sense key of
NOT READY
, with additional sense of 0401h (drive
in process of becoming ready).
Reset strategy
The drive supports reset as follows:
•
The current I/O process is aborted
• Any queued I/O processes from other initiators are removed
• All negotiated settings are cleared
(parallel SCSI drives only)
• Mode parameters are cleared to their default values
• Any reservations are cleared (but not persistent reservations)
• Any buffered writes are flushed to tape
• The logical position becomes undefined, unless Rewind-On-Reset has been configured in
which case the drive will rewind to BOM
08h
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28h READ 10 2Bh SEEK
25h READ CAPACITY 1Bh START/STOP UNIT