Fibre Channel Interface Manual, Rev. D 161
12.5 Format Unit command
The Format Unit command ensures that the medium is formatted so all of the user-addressable data blocks
can be accessed. There is no guarantee that the medium has or has not been altered. In addition, the medium
may be certified and control structures may be created for the management of the medium and defects.
The drive allows an initiator to specify (or not specify) sectors which are to be reallocated during the format pro-
cess. The format parameters to be specified in the Format Unit command are defined in Table 97.
The Format Unit command is rejected with Reservation Conflict status if the logical unit is reserved, or any
extent reservation, from any initiator, is active in the specified logical unit.
During the format operation, the target responds to commands as follows:
• In response to all commands except Request Sense and Inquiry, the target returns Check Condition status
unless a reservation conflict exists, in which case Reservation Conflict status is returned.
• The target responds to the Inquiry and Request Sense commands normally.
Field definitions (listed alphabetically)
CMP LST (Complete List)
1 The data supplied is the complete list of Growth defects. Any previous Growth defect data or Certification defect
data is erased. The disc drive adds to this list as it formats the medium. The result is to purge any previous Growth
or Certification defect list and to build a new defect list.
1 When FMT DATA equals 0, the Format Unit command is terminated with Check Condition status and a sense key of
Illegal Request.
0 The data supplied is in addition to the existing Growth defect list.
The use of the P list and C list defect is controlled by byte 1 of the defect list header (see Table 98).
Control
See Control Bytes in Section 11.2.1.6.
Defect List Format
Specifies additional information related to the defect list. (See Table 97 for further information.)
FMT DATA (Format Data)
1 The Format Unit Parameter list (Section 12.5.1) is supplied in a data transfer. The data transferred consists of a
defect list header (Table 98), followed by an initialization pattern descriptor (Table 99 if any) followed by the defect
descriptors. The format of the defect descriptor list is determined by the Defect List Format field.
0 The data transfer does not occur (no defect data will be supplied by the initiator).
Table 96: Format Unit command (04h)
Bit
Byte
76543210
000000100
100
Reserved
0FMT
DATA
CMP
LST Defect List Format
200000000
3
4Interleave
5Control
04h
Table
number
96
96
96
96