2.3 Defect Management
C156-E228-02EN 2-11
2.3 Defect Management

2.3.1 Defect management schematic diagram

Defective sectors on the disk must be replaced with good sectors in accordance
with the defect management scheme as follows: Sectors found defective during
surface inspection are handled using a sector slipping algorithm. Sectors found
defective after initialization are replaced using a linear replacement algorithm.
Figure 2.2 shows the sector slipping and linear replacement algorithms.
(a) Sector slipping algorithm (b) Linear replacement algorithm
Figure 2.2 Algorithms for alternate processing
During initialization, the user area is divided into several groups. Each of the
groups contains data sectors and spare sectors. Spare sectors are used as
replacements for defective data sectors. During initialization, the surface
inspection over the user area can be performed.
Figure 2.3 shows an example of alternate processing.