Seagate MEDALIST 1080SL Product Manual page 43

Medalist 1080sl SCSI Product Manual, August 1995
3.4.4.1 Defect lists
When the Format Unit command is issued, media defect information can
be gathered from several sources. Four of these sources—primary
defect list, certification defect list, data defect list and grown defect
list—are defect lists written to the drive. They are defined below. Assign-
ments in Byte 1 of the defect list header—described in Section 3.4.4.3—
determine the use of the defect list during formatting. The Reassign
Blocks and Read Defect Data commands also use these lists.
The primary defect list (PList) is a list of media defects found when
the drive is manufactured and written to the disc in an area that is not
directly accessible by the user. These defects are considered perma-
nent and cannot be changed.
The certification defect list (CList) is a list of unrecoverable sectors
that the drive reads during the certify of the Format Unit command.
The data defect list (DList) is a list of sectors the initiator supplies to
the drive during a data-out phase of the current Format Unit command.
The drive sends the DList in the last bytes of the defect list (described
in Section 3.4.4.3) and adds it to the GList.
The grown defect list (GList) is a list of defects supplied by the initiator
or detected by the target but does not include defects from the PList.
The GList includes defects detected by the format operation during
media certification, the DList, defects previously identified with a
Reassign Blocks command and defects previously detected by the
target and automatically reallocated.
3.4.4.2 Format Unit parameters
For each format listed below, except the default format, the initiator sends
a defect list header. This header is described in Section 3.4.4.3. The
bytes-from-index format is described in Section 3.4.4.4 and the physical
sector format is described in Section 3.4.4.5. The block format is not
supported.
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