User Manual

SCSI Commands Reference Manual, Rev. J 71

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

3.3 FORMAT UNIT command

3.3.1 FORMAT UNIT command overview

The FORMAT UNIT command (see table 35) requests that the device server format the medium into application client accessible

logical blocks as specified in the number of blocks and block length values received in the last mode parameter block descriptor

(see 5.3.4) in a MODE SELECT command (see 3.9 and 3.10). In addition, the device server may certify the medium and create

control structures for the management of the medium and defects. The degree that the medium is altered by this command is

vendor-specific.

If a device server receives a FORMAT UNIT command before receiving a MODE SELECT command with a mode parameter block

descriptor the device server shall use the number of blocks and block length at which the logical unit is currently formatted (i.e.,

no change is made to the number of blocks and the block length of the logical unit during the format operation).

While performing a format operation, the device server shall respond to commands attempting to enter into the task set except

INQUIRY commands, REPORT LUNS commands, and REQUEST SENSE commands with CHECK CONDITION status with the sense

key set to NOT READY and the additional sense code set to LOGICAL UNIT NOT READY, FORMAT IN PROGRESS. Handling of

commands already in the task set is vendor-specific. If the device server receives an INQUIRY command, a REPORT LUNS

commands, or a REQUEST SENSE command, then the device server shall process the command. The device server shall return

data for an INQUIRY command based on the condition of the SCSI target device before beginning the FORMAT UNIT command

(i.e., INQUIRY data shall not change until after successful completion of a format operation). The processing of commands in the

task set when a FORMAT UNIT command is received is vendor specific.

Table 35 FORMAT UNIT command

Bit

Byte

7 6 5 4 3 2 1 0

OPERATION CODE (04h)

FMTPINFO LONG-LIST FMTDATA CMPLIST DEFECT LIST FORMAT

Vendor Specific

Reserved

FFMT

CONTROL