User's Manual

DLT4000 SCSI Interface
DLT4000/DLT4500/DLT4700 Cartridge Tape Subsystem 8-129
8.4.27 WRITE FILEMARKS (10h)
Bit
7 6 5 4 3 2 1 0
0 Operation Code (10h)
1 Logical Unit Number Reserved WSmk Immed
2 (MSB)
Byte 3 Number of Filemarks
4 (LSB)
5 Unused Reserved Flag Link
Figure 8-82 WRITE FILEMARKS CDB
WRITE FILEMARKS causes the specified number of Filemarks to be written
beginning at the current logical position on tape. If the Immed bit is not set, any data
or Filemarks in the write cache buffer are written to tape.
WSmk
If this bit is set, the tape drive writes a save-set mark to tape instead of a Filemark.
Since Setmarks are not supported by the DLT4000 drive, this field must be zero.
Immed
If this bit is set, the drive returns status as soon as the command descriptor block has
been validated, unless the filemark count is zero, or greater than 1 (since both cause
the write buffer to be flushed to media). An Immed bit of zero indicates the status will
not be returned until the operation is complete.
Number of Filemarks
This is the number of consecutive marks to be written to tape. A value of zero is not
considered an error and GOOD status is returned.
This command may be used to force the drive to write any buffered write data to the
tape. If the drive is in Buffered mode, and WRITE FILEMARKS is received, the
requested Filemarks are appended to the data, and the write buffer is flushed to tape.
A zero value in the Number of Filemarks field indicates that no Filemarks are to be
written to the tape, but still flushes any write data to tape.
If EOT is detected while writing Filemarks, the drive finishes writing any buffered
data and terminates with CHECK CONDITION status. Within the Sense data, the
EOM bit is set, the Sense Key field is set to NO SENSE and the Additional Sense
Code and Additional Sense Code Qualifier fields are set to EOM/P detected. The drive
will attempt to complete any subsequent WRITE FILEMARKS, returning a CHECK