HP C2488A Technical Reference Manual page 94

Reassign Blocks
Defect List Descriptor Format
Bit
Byte
7
I
6
I
5
t
4
J
3
I
2
I
1
I
0
00-03
(MSB=OO)
Defect Logical Block Address
(LSB=03)
The Defect Descriptor specifies a 4-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 logical blocks specified in the
defect descriptors, the command shall terminate with a CHECK CONDITION status and the
Sense Key will be set to MEDIUM ERROR. The additional Sense Code will be NO DEFECT
SPARE LOCATION AVAILABLE (32H). The logical block address of the first logical block
not reassigned shall be returned in the Information Bytes-of the sense data.
During a reassign operation, all data residing on the track with the specified defective
block(s), except that contained within the defective block(s), is moved to a new physical track.
If the Target is unable to recover data from any of these block( s) affected by the operation
but not contained in the defect descriptor list, the command is terminated with CHECK
CONDITION status and a Sense Key of MEDIUM ERROR. The additional Sense Code will
be set to UNRECOVERED READ ERROR (llH), and the information bytes will contain the
logical block address of the new defect. These additional defect(s) should be added to the
reassignment defect list and the command reissued.
All blocks affected by the reassignment operation but not included in the defect descriptor
list, are verified following the reassignment. If the verification fails, the data will be reassigned
to another physical location. If this second reassignment operation fails, the command is
terminated with CHECK CONDITION status, a Sense Key of MEDIUM ERROR, and an
additional sense code of SPARE OPERATION FAILED. In this case, the media configuration
remains as it was prior to the command. The spare track on which the original verify failed is
marked as bad. This allows a reissue of the same Reassign Blocks c-ommand to step through
spare tracks if consecutive spare tracks are defective. Multiple failures of this command
probably indicate a hardware failure ..
A-38 SCSI Command Descriptions
DRAFT
1/18/93 09:58