Fujitsu MBB2073RC User Manual download pdf (Page 38)

Data Format

3.1.5 Format capacity

The size of the usable area for storing user data on the HDD (format capacity) varies according to the

logical data block or the size of the spare sector area. Table 3.1 lists examples of the format capacity

when the typical logical data block length and the default spare area are used. The following is the

general formula to calculate the format capacity.

[Number of sectors of each zone] = [number of sectors per track × number of tracks per cell –

number of alternate spare sectors per cell] × [number of cells in the zone]

[Formatted capacity] = [total of sectors of all zones] ÷ [number of physical sectors in logical block] ×

[logical data block length]

The following formula must be used when the number of logical data blocks are specified with the

parameter in the MODE SELECT or MODE SELECT EXTENDED command.

[Format capacity] = [logical data block length] × [number of logical data blocks]

The logical data block length, the maximum logical block address, and the number of the logical data

blocks can be read out by a READ CAPACITY, MODE SENSE, or MODE SENSE EXTENDED

command after initializing the disk.

Table 3.1 Format capacity

Model Data block length User blocks Format capacity

MBB2147RC 287,277,984 147 GB (*)

MBB2073RC

512

143,638,992 73.5 GB (*)

(*) One gigabyte (GB) = one billion bytes; accessible capacity will be less and actual capacity depends

on the operating environment and formatting.

Note:

Total number of spare sectors is calculated by adding the number of spare sectors in each primary

cylinder and the number of sectors in the alternate cylinders.

3.2 Logical Data Block Addressing

The HDDs relate a logical data block address to each physical sector at formatting. Data on the disk

is accessed in logical data block units. The initiator specifies the data to be accessed using the logical

data block address of that data.

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Fujitsu MBB2073RC User Manual Page 38