Fujitsu MAP3147, MAP3367, MAS3735, MAP3735, MAS3367 Disk Media Management, Defect Management

CHAPTER 6 Disk Media Management

6.1Defect Management

6.2Disk Media Initialization

6.3Data Block Verification Methods (Recommended)

6.4Alternate 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.

6.1Defect 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.

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