Reassign Blocks Defect List - Seagate SCSI Interface Product Manual

SCSI Interface Product Manual, Rev. J
5.27.1

Reassign Blocks defect list

The Reassign Blocks defect list (Table 134) contains a four byte header followed by one or more Defect
Descriptors. The length of each Defect Descriptor is four bytes.
Table 134: Reassign Blocks defect list
Bit 7
Byte
0 0
1 0
2 Defect List Length (MSB) [1]
3 Defect List Length (LSB)
0 Defect Logical Block Address (MSB) [2]
1 Defect Logical Block Address
2 Defect Logical Block Address
3 Defect Logical Block Address (LSB)
Notes.
[1] The Defect List Length specifies the total length in bytes of the Defect Descriptors that follow. The Defect
List Length is equal to four times the number of Defect Descriptors.
[2] The Defect Descriptor specifies a four byte Defect Logical Block Address that contains the defect. The
Defect Descriptors shall be in ascending order.
If the logical unit has insufficient capacity to reassign all of the defective logical blocks, the command shall ter-
minate with a Check Condition status and the Sense Key shall be set to Hardware Error and the additional
sense code set to No Defect Spare Location Available. The logical block address of the first logical block not
reassigned shall be returned in the information bytes of the sense data. If information about the first defect
descriptor not reassigned is not available, or if all the defects have been reassigned, this field shall be set to
FFFFFFFFh.
If the Reassign Blocks command failed due to an unexpected unrecoverable read error that would cause the
loss of data in a block not specified in the defect list, the logical block address of the unrecoverable block shall
be returned in the information field of the sense data and the valid bit shall be set to one.
IMPLEMENTORS NOTE: If the Reassign Blocks command returns Check Condition status and the sense data
command-specific information field contains a valid logical block address, the initiator should remove all defect
descriptors from the defect list prior to the one returned in the command-specific information field. If the sense
key is Medium Error and the valid bit is one (the information field contains the valid block address), the initiator
should insert that new defective logical block address into the defect list and reissue the Reassign Blocks com-
mand with the new defect list. Otherwise, the initiator should perform any corrective action indicated by the
sense data and then reissue the Reassign Blocks command with the new defect list.
6 5
Defect List Header
0 0
0 0
Defect Descriptor(s)
4 3
0 0
0 0
2 1
0 0
0 0
177
0
0
0