Appendix C
Media
Defect
Handling
and
Error
Correcting
Code
ProDrive
40S
80S
Sectors/
Head
CYL
0
I
2
CYL+l
0
1
2
NOTES:
Head
CYL
0
x+O
x+l
x+2
28
29
I
x+
xxxx
x+"
35 36
2
3
4
139
140
141
5
x+
x+
x+
174
175
176
x
= logical block address
xxxx = deallocated sector
Zone size is six tracks/zone (default)
x+
x+
x+
FIGURE
C-l
Factory Found Defects
FIELD FOUND DEFECTS
25
26 27
x+ x+
32 33 34
52 53 54
x+
x+
66
67
68
164 165 166
x+ x+
206
207
208
,ProDrive Series disk drives also contain a Replacement Sector Map in the event additional defects are
found during drive usage. Field found, or
"grown" defects are also mapped into the one replacement sector
located
at
the end
of
each zone. However, data from field-found defective sectors are mapped directly into
;the spare sector location (without shifting subsequent logical blocks, as in the case
of
the In-Line sparing
method); see Figure C2.
Similar to the factory sparing method, in the rare instance where there are more
than one defect per zone, the additional defects will
be mapped into the nearest adjacent zone with a spare
sector available. This approach ensures that in most cases a long seek to an alternate cylinder will not
be
necessary in order to manage additional defects found during drive usage.
C-2
Appendix C
Media
Defect
Handling
and Error Correcting
Code
track
28
35
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