Fujitsu 80, Scsi Logical Interface Specifications

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6.2 Disk Media Initialization
C141-C010 6-5
6.2.2 Re-initialization
The INIT can reinitialize the disk drive after it has been operated using the FORMAT UNIT command.
Note:
If it is necessary after reinitialization to restore the data that were stored on the disk media, it is
necessary to save the data before executing reinitialization, then execute data restore using system
software after reinitialization.
The INIT can change the size of the spare sector area and its location as well as the number of logical
data blocks before reinitialization. The recommended procedure for reinitialization is shown below.
However, in cases where the logical data block length is changed, the initialization procedure described
in Section 6.2.1 must be followed during installation.
(1)
MODE SELECT command
If the logical data block count (size of the User Space) or the size of the spare sector area and its location
are changed, issue the MODE SELECT EXTENDED command and specify the disk media format
attributes. The parameter specification method is the same as in the case of initialization processing
during installation, described in Section 6.2.1. If the same format attributes as at present will continue to
be used, it is not necessary to issue the MODE SELECT EXTENDED command.
(2) FORMAT UNIT command
Issue the FORMAT UNIT command in either of the following two formats and initialize the entire disk
media surface.
a) Specify "1" in the "FmtData" bit, "0" in the "CmpLst" bit and "000" in the "Defect List Format"
field. Also, prepare only a 4-byte header, specify "0" in the "FOV," "DPRY," "DCRT" and "STPF"
bits and zero in the "Defect List Length" field.
•
In this FORMAT UNIT command, the entire disk media surface is initialized using the P List
and the previously existing G List, then after initialization, the data blocks are verified. If any
defective blocks are detected in the Verify operation, alternate blocks are allocated for those
data blocks. Also, the previously existing G List is saved, and the defect position information
for the defective data blocks detected in the Verify operation is added to the G List. During
initialization, alternate blocks for which sector slip processing was applied for previously
known defects are reallocated, so optimization of the logical data block locations on the disk
media can be expected.
b) Specify "0" in the "FmtData" bit and in the "CmpLst" bit and "000" in the "Defect List Format" field.
In this case, specification of the format parameters is not necessary.
•
In this FORMAT UNIT command, the disk media is initialized using only the P List, then after
initialization, the data blocks are verified. If any defective blocks are detected in the Verify
operation, alternate blocks are allocated for those data blocks. Also, the previously existing G
List is erased and defect position information for the defective data blocks detected in the
Verify operation is recorded in a new G List.