Quantum LTO 4, User Manual

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SCSI Commands: 37BREPORT LUNS Page 160
3.25 REPORT LUNS
The host uses this command to retrieve information about which Logical Units the
drive supports. The allocation length shall be at least 16 bytes. If this is not the case,
drive will return Check
Condition status and provide a sense key of Illegal Request and
additional sense of INVALID FIELD IN CDB.
3.25.1 REPORT LUNS Command Descriptor Block
The following table shows the layout of the CDB.
Byte Bits
7 6 5 4 3 2 1 0
0 Operation Code (A0h)
1 Ignored LUN Reserved
2 Reserved
3 Reserved
4 Reserved
5 Reserved
6 (MSB)
7
8
9
Allocation Length
(LSB)
10 Reserved
11 Control
3.25.1.1 REPORT LUNS Command Field Descriptions
Field Bytes Bits Description
Operation
Code 0 The Operation code for REPORT LUNS is A0h.
Ignored
Logical Unit 1 5-7 The LUN field is vestigial from the SCSI-1 standard and is
ignored.
Allocation
Length 6-9 Specifies the amount of data to be returned, in bytes. Must be
at least 16 bytes or the drive will return Check Condition.
Reserved All reserved bits must be 0.
Control 11 See SCSI Command Control Byte Format on page 25.
3.25.2 REPORT LUNS Data
The following header is returned by the REPORT LUNS command.
Byte Bits
7 6 5 4 3 2 1 0
0 (MSB)
1
2
3
LUN List Length
(LSB)
4 Reserved
5 Reserved
6 Reserved