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CHAPTER 6 Disk Media Management
6.1 Defect Management
6.2 Disk Media Initialization
6.3 Data Block Verification Methods (Recommended)
6.4 Alternate Block Allocation Processing
In this chapter, disk media defect management methods, treatment methods for media defects which occur
during operation, reinitialization procedures and other disk media management methods are discussed.
Furthermore, see Chapter 3, "Data Format" in the "Product Manual" concerning details of the data recording
format on the disk media.
6.1 Defect Management
(1) Defect lists
Information on the positions of defects in the disk media are managed by the types of defect list
shown below. See the description of the FORMAT UNIT command (Section 3.3.1) concerning
methods for using the defect lists.
• P List Defect position information at the point when the disk drive was shipped from the
factory is recorded in this list. The defective portions included in this list are permanent
defects, and when the disk media is initialized, it is necessary that this list be used and
alternate block processing be executed.
• D List This list includes defect position information specified by the INIT in the FORMAT
UNIT command when initializing the disk media.
• C List This list contains information on the positions of defective blocks detected during the
data block Verify operation (Certification) after initialization by the FORMAT UNIT
command. This information is generated internally by the IDD when the FORMAT
UNIT command is executed.
• G List This list is composed from the defective logical data block position information
specified by the INIT in the REASSIGN BLOCKS command, defective logical data
block position information from alternate blocks which have been allocated by the
IDD's auto alternate block allocation processing, information specified as the D List and
information generated as the C List.
The P List and G List are recorded in the system space on the disk media. The INIT can read the
contents of these lists by the READ DEFECT DATA command.