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27 write filemarks command (10h) – Quantum Instruments DLT 7000 User Manual

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SCSI Commands

Quantum DLT 7000 Tape System

5-173

5.27 WRITE FILEMARKS COMMAND (10h)

The WRITE FILEMARKS command directs the tape drive to write the specified
number of Filemarks beginning at the current logical position on tape. If the
Immediate bit is not set, any data or Filemarks in the WRITE cache buffer are
written to tape.

Bit

Byte

7

6

5

4

3

2

1

0

0

Operation Code (10h)

1

Logical Unit Number

Reserved

WSMk

(0)

Immed

2 - 4

(MSB)

Number of Filemarks

(LSB)

5

Unused

Reserved

Flag

Link

Figure 5–83 WRITE FILEMARKS Command Descriptor Block - Data Format

Table 5–84 WRITE FILEMARKS Command Data - Field Descriptions

Field Name

Description

WSmk

Write Setmark. Must be 0. This tape drive does not support Setmarks.

Immed

Immediate. When this bit is set to 1, the tape drive returns status as soon as the
Command Descriptor Block (CDB) has been validated, unless the Filemark count
is 0, or greater than 1 (since either condition causes the WRITE buffer to be
flushed to tape medium).
When set to 0, this bit indicates the status will not be returned until the
operation is complete.

Number of
Filemarks

This field contains the number of consecutive Filemarks to be written to tape
medium. A value of 0 is not considered to be an error; GOOD status is returned.