Alternate Block Allocation Processing - Fujitsu MAX3036RC SERIES Specifications

Disk Media Management
(3) Reading and verification of data
Issue the READ, READ EXTENDED or VERIFY command and verify that the
data written to the disk media in item (2) were read correctly.
To verify reading of data, it is recommended that reading of the same data block
be done at lease 2 times, but the number of times verification is performed is
determined by the conditions on the system. If reading of all data is completed
normally, it can be recognized that use of that data block can be used normally.
(4) Error verification
When an error related to the disk media (Sense Key = 3: MEDIUM ERROR)
occurs during writing of the data pattern (see item (2)) or verification of data
reading (see item (3)), reexecute the rewriting and reading verification
combination (two times) at least 8 times.
When the same type of error occurs even once during reexecution, it is
recommended that the INIT treat that data block as a defective block. If the
reexecution of verification is completed normally every time, it should be
regarded that that data block can be used normally.

6.4 Alternate Block Allocation Processing

If errors on the disk media which cannot be recovered from are detected, or if a
recoverable error occurs repeatedly in the same data block, it is necessary for the
INIT to allocate an alternate block for the data block where the error occurred
using the REASSIGN BLOCKS command. The procedure for alternate block
processing is shown below.
An attempt will be made to copy the contents of the data area of the
logical data block specified in the "Defect Data" list to the alternate
block allocated by this command, but in some cases, the data cannot
be copied. Confirmation of the contents of data in the allocated
alternate block, saving of data before issuing this command and
restoring of data after executing this command are the responsibility
of the INIT.
1) Verify data blocks in accordance with the procedure in Section 6.3 for data
blocks where error occurs. When such a data block is judged to be normal,
alternate block allocation need not be implemented. In this case, rewrite the
original data to that data block if necessary. When the data block is judged to
be defective, implement the processing in item 2) and after.
2) Specify a logical block address for a data block which is judged to be
defective and issue the REASSIGN BLOCKS command.
6-8 C141-C012