scope:

This standard defines the command set extensions to facilitate operation of SCSI direct access block devices. The clauses in this standard, implemented in conjunction with the applicable clauses of SPC-6, specify the standard command set for SCSI direct access block devices.

The objectives of this standard are to:

a) permit an application client to communicate over a SCSI service delivery subsystem (see SAM-6) with a logical unit that declares itself to be a direct access block device in the PERIPHERAL DEVICE TYPE field of the standard INQUIRY data (see SPC-6); and

b) define commands and parameters unique to the direct access block device type.

This standard makes obsolete the following concepts from SBC-3:

a) the EER bit and DCR bit (see 6.5.10);

b) the TMC field and ETC bit in various log parameters;

c) the READ LONG command and WRITE LONG command except for write uncorrectable; and

d) the XOR command.