Fujitsu MBC2036RC, MBC2073RC, MBA3300RC, MBA3147RC, MBA3073RC Error recovery processing control

Sense Data and Error Recovery Methods

If error recovery is completed by rewriting the data to the data block, alternate block allocation is not performed for this data block. The data block is removed as the target of AWRE processing.

(3)Auto alternate block allocation processing during a write operation 2 (servo auto alternate)

This function is enabled by specifying "1" in the AWRE flag in the MODE SELECT parameters. Furthermore, this function is applicable to the following commands only.

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∙

∙

WRITE command

WRITE EXTENDED command

WRITE AND VERIFY command

When this function is permitted, if, during WRITE/WRITE EXTENDED command detects any Servo error (e.g. Write offtrack error) and cannot be recovered within pre-determined retry number (specified in Mode Parameter). For the sectors around defective Servo, alternate blocks are allocated and the data of this WRITE commands are re-written.

Sectors to be made AWRE shall be following:

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∙

∙

∙

the sector where the error occurs and the latter sectors and,

the sectors whose data are logically continual and stored in Cache,

the sectors which will be processed in this Write command and,

the sectors which locate between erroneous Servo -1 and +1 (including Split sector)

This function is also applied for the sector which has already been re-assigned.

6.3.3 Error recovery processing control

The INIT can, by specifying the MODE SELECT parameters, can control the error recovery processing (retries) of the HDD with respect to each type of error related to the disk drive.

Table 6.7 shows the types of error and the method of specifying the number of retries for those errors. for those items where the INIT can specify the number of retries, normally, it is recommended that the default value or a greater number of times be specified. If a value smaller than the default value is specified, and commands are terminated abnormally without error recovery processing succeeding, the INIT should reset the corresponding MODE SELECT parameters at the default value, then reexecute the original commands.

The MODE SELECT parameters related to disk drive error recovery processing which the INIT can specify are shown below. See the description of the MODE SELECT command (Section 4.1.4) concerning details of the functions of each parameter. The INIT can issue the MODE SELECT or MODE SELECT

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