1 overview of the scsi command descriptions – Quantum 10K II User Manual

Page 70

Advertising
background image

SCSI Description

Quantum Atlas 10K II Ultra160/m SCSI Hard Disk Drives

5–3

5.1

OVERVIEW OF THE SCSI COMMAND DESCRIPTIONS

The disk drives support the SCSI-3 commands listed in Table 5-1. The command
categories are

sequential, normal, and immediate.

Immediate commands are processed when received by the drive. In most cases, these
commands do not require drive resources, do not change the state of the drive, and
bypass the command queue (unless the command is tagged).
Sequential commands execute in the order that they arrive (unless accompanied by
a HEAD OF QUEUE tag) and execute to completion before a subsequent command
is activated.
Normal commands are allowed to execute concurrently (with the restriction that the
drive executes overlapping writes in the order received). Normal commands are
usually I/O commands.

Table 5–1 Supported SCSI Commands

Command

Operation Code

Category

CHANGE DEFINITION

40h

Sequential

FORMAT UNIT

04h

Sequential

INQUIRY

12h

Immediate

LOG SELECT

4Ch

Sequential

LOG SENSE

4Dh

Sequential

MODE SELECT (6)

15h

Sequential

MODE SELECT (10)

55h

Sequential

MODE SENSE (6)

1Ah

Sequential

MODE SENSE (10)

5Ah

Sequential

PERSISTENT RESERVATION IN

5Eh

Sequential

PERSISTENT RESERVATION OUT

5Fh

Sequential

READ (6)

08h

Normal

READ (10)

28h

Normal

READ BUFFER

3Ch

Sequential

READ CAPACITY

25h

Immediate

READ DEFECT DATA (10)

37h

Sequential

READ DEFECT DATA (12)

B7h

Sequential

READ LONG

3Eh

Sequential

READ SKIP MASK

E8h

Normal

REASSIGN BLOCKS

07h

Sequential

RECEIVE DIAGNOSTIC RESULTS

1Ch

Sequential

(continued…)

Advertising