Fujitsu MBB2073RC, MBB2147RC manual Data Space Logical Data Block Addressing Defect Management

CHAPTER 3 Data Format

3.1Data Space

3.2Logical Data Block Addressing

3.3Defect Management

This chapter explains data space definition, logical data block addressing, and defect management on the HDDs.

3.1Data Space

The HDDs manage the entire data storage area divided into the following three data spaces.

•User space: Storage area for user data

•Internal test space: Reserved area for diagnostic purposes

•System space: Area for exclusive use of HDDs themselves

The user space allows a user access by specifying data. These spaces can be accessed with the logical data block addressing method described in Section 3.2. The internal test space is used by Read/write test of self-diagnostics test, but user can’t use direct access. The system space is accessed inside the HDDs at power-on or during the execution of a specific command, but the user cannot directly access the system space.

3.1.1Cylinder configuration

The HDDs allocate cylinders to the user space, Internal test space, and system space. Figure 3.1 is the cylinder configuration.

Spare areas (alternate areas) for defective sectors are provided in the user space. Several sectors in the last track of each cell and the last 10 cylinders of the last zone are allocated as alternate areas according to the user's assignment (MODE SELECT command). See Subsection 3.1.2 for details.

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