Fujitsu MBA3073RC, MBC2036RC, MBC2073RC Disk Media Management, Alternate block allocation

Models: MBA3300RC MBA3147RC MBA3073RC MBC2073RC MBC2036RC

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Disk Media Management

(2) Alternate block allocation

Alternate data blocks are allocated in defective sector units for defective data blocks (= sectors) on the disk media by the HDD's internal defect management methods.

a.Spare sector area

Spare sectors for allocation as alternate blocks are secured in one or both of the following areas. When the INIT initializes the disk media, it can specify the spare sector area to be prepared on the disk drive and the size of that area.

Spare sectors within a cell

Spare sectors are secured in the final track of each cell. They are used as alternate blocks for defective sectors within the same cell.

Alternate cells

This is an exclusive cells for allocation of alternate blocks. Alternate cells are secured only in the specified quantity in order from the topmost cells. Spare sectors in an alternate cell are used only in the case that the spare sectors within each cell are used up and alternate block allocation is not possible within the same cell.

b.Alternate block allocation methods

Alternate block allocation processing is performed using one of the following methods.

Sector slip processing

This is a method of skipping defective sectors and writing the logical data blocks corresponding to those sectors in order in physically consecutive sectors. Sector slip processing is performed only within the same cell as the defective sectors and until all the spare sectors within that cell are used up.

Alternate sector processing

This is a method of allocating logical data blocks corresponding to defective sectors to unused spare sectors in an alternate cell.

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C141-C013

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Fujitsu MBA3073RC, MBC2036RC, MBC2073RC, MBA3300RC, MBA3147RC specifications Disk Media Management, Alternate block allocation