User Manual

SCSI Commands Reference Manual, Rev. J 180

www.seagate.com Direct Access Block commands (SPC-5 and SBC-4)

The REPORT LUNS parameter data should be returned even though the device server is not ready for other commands. The

report of the logical unit inventory should be available without incurring any media access delays. If the device server is not

ready with the logical unit inventory or if the inventory list is null for the requesting I_T nexus and the SELECT REPORT field set to

02h, then the device server shall provide a default logical unit inventory that contains at least LUN 0 or the REPORT LUNS well

known logical unit. A non-empty peripheral device logical unit inventory that does not contain either LUN 0 or the REPORT LUNS

well known logical unit is valid.

If a REPORT LUNS command is received for a logical unit that the SCSI target device does not support and the device server is not

capable of returning the logical unit inventory, then the command shall be terminated with CHECK CONDITION status, with the

sense key set to ILLEGAL REQUEST, and the additional sense code set to LOGICAL UNIT NOT SUPPORTED.

The device server shall report those devices in the logical unit inventory using the format shown in table 149.

LUN LIST LENGTH field

The LUN LIST LENGTH field shall contain the length in bytes of the LUN list that is available to be transferred. The LUN list length is the number

of logical unit numbers in the logical unit inventory multiplied by eight. The relationship between the LUN LIST LENGTH field and the ALLOCA-

TION LENGTH field is defined in 2.2.6.

Table 149 REPORT LUNS parameter data format

Bit

Byte

7 6 5 4 3 2 1 0

(MSB)

LUN LIST LENGTH (N-7)

. . .

(LSB)

Reserved

. . .

LUN list

LUN [first]

. . .

n-7

LUN [last]

. . .