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4.3 Format Commands
C141-C013 237
The HDD allocates alternate blocks to the specified data blocks in order from the
top of the defect descriptor list. When all the usable spare sectors have been used
up, and it is impossible to allocate alternate blocks, execution of this command is
terminated at that point and a CHECK CONDITION status is reported. The sense
data at this time indicate the following contents.
• Sense key: 4 = HARDWARE ERROR
• Additional sense code/: 32-00 = No defect spare location available
Additional sense code qualifier
• "VALID" bit: "1"
• Information field Logical block address specified in the defect
descriptor at the point when alternate block
allocation becomes impossible.
• Command inherent
information field
Also, when this command is terminated abnormally with a CHECK CONDITION
status due to any one of several other types of error besides the above error, the
logical block address specified in the first defect descriptor which did not undergo
alternate block allocation is reported in the "Command inherent information" field
in the sense data. However, if alternate block allocation processing of the defect
descriptors for which alternate block allocation has not been implemented cannot
be specified, or if alternate block allocation of all the specified defect descriptors
has been completed, the "Command inherent information" field indicates X
'FFFFFFFF.'
When alternate block allocation processing is successful, the defect position
information on the disk media related to the data blocks specified in the defect
descriptor list is recorded on the disk media as the defect list (G List). The INIT can
read the contents of the G List using the READ DEFECT DATA command. Also,
this command has no influence on the contents of the primary defect list (P List).
The defect position information in the G List is physical block
addresses (logical data block addresses are allocated when no defect
exists on the disk media). Therefore, the values specified in this
command's defect descriptor list (logical block addresses) may not
necessarily be the same as the contents of the G List read by the
READ DEFECT DATA command after this command is
terminated. For details, see the description of the READ DEFECT
DATA command (Section 4.3.3).