SCSI Commands
5-158
Quantum DLT 4000 Tape Drive
WRITE Command (0Ah) (continued)
Table 5–78 WRITE Command Data - Field Descriptions
Field Name
Description
Fixed
The fixed bit specifies both the meaning of the Transfer Length field and
whether fixed-length or variable-length blocks are to be transferred.
When the Fixed bit is 0, Variable-length block mode is selected. A single block
is transferred from the initiator and is written to the logical unit beginning at
the current logical tape position. Upon successful termination, the tape is
logically positioned after this block (on the EOM/P side). The Transfer Length
specifies the number of bytes that the drive handshakes out from the initiator
as one block.
When the Fixed bit is 1, the Transfer Length field specifies the number of blocks
to be transferred to the host beginning at the current tape position. This form
of WRITE is valid only if the logical unit is currently operating in the Fixed Block
mode – when it has been instructed to use fixed-length blocks with MODE
SELECT. The current block length is the block length defined in the MODE
SELECT command. Upon termination, the tape is logically positioned after
these blocks.
Transfer Length
This field contains the length of the data transfer in bytes or blocks depending
on whether Fixed or Variable block mode is selected.
When the Transfer Length is 0, no data is transferred and the current position
on the logical unit is not changed.
Exception Conditions
If End of Tape (EOT) is detected while writing, the tape drive finishes writing
any buffered data. The command terminates with CHECK CONDITION status.
Within the sense data, the EOM bit is set, the Sense Key is set to NO SENSE,
and the Additional Sense code and Additional Sense Code Qualifier fields are set
to EOM/P detected. The drive attempts to complete any subsequent writes,
returning a CHECK CONDITION status in each case.
If the tape drive encounters the physical End of Medium (EOM) when
attempting WRITE, a CHECK CONDITION status is returned. Within the sense
data, the EOM and Valid bits are set, and the Sense Key field is set to Volume
Overflow. The Information fields contain the residue count and the Additional
Sense code and Additional Sense Code Qualifier fields are set to EOM/P
Detected. The tape is physically positioned at EOM/P.
Содержание DLTtape DLT 4000
Страница 1: ...DLT 4000 Tape Drive Product Manual November 10 2003 81 60043 04 ...
Страница 5: ...USER MANUAL STATEMENTS FOR CLASS B EQUIPMENT continued ...
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Страница 24: ...About This Manual Quantum DLT 4000 Tape Drive xxiv ...
Страница 62: ...Hardware Implementation 2 28 Quantum DLT 4000 Tape Drive ...
Страница 100: ...Messages 4 12 Quantum DLT 4000 Tape Drive ...
Страница 264: ...SCSI Commands 5 164 Quantum DLT 4000 Tape Drive ...
Страница 274: ...Appendix B EEPROM Resident Bugcheck and Event Logs B 6 Quantum DLT 4000 Tape System ...
Страница 280: ...Appendix C Updating the Firmware C 6 Quantum DLT 4000 Tape Drive ...
Страница 298: ...Index Index 6 Quantum DLT4000 Tape Drive ...
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