(2)Alternate cylinder assignment

A defective sector is assigned to the spare sector in the alternate cylinder.

This processing is performed when a physical track contains three or more defective sectors, and when the automatic alternate processing is performed.

Figure 6.8 shows an example where (physical) sector 5 is detective on head 0 in cylinder 0.

Index

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Sector (physical)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1

2

3

4

5

 

6

7

 

407299

 

408

 

 

 

Cylinder 0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Defective

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Head 0

 

 

 

 

 

 

 

 

sector

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1

2

3

4

(unused)

6

7

405

 

406

 

 

 

 

 

 

300299

 

 

 

Sector (logical)

Alternate

cylinderAlready assigned

Head 0

Defective sector is assigned to unassigned sector.

14 alternatecylinders areis providedinforoutereach sidehead. in zone 13 (inner side).

When an access request to sector 5 is specified, the device accesses the alternated sector in the alternate cylinder instead of sector 5. When an access request to sectors next to sector 5 is specified, the device seeks to cylinder 0, head 0, and continues the processing.

Figure 6.8 Alternate cylinder assignment

(3)Automatic alternate assignment

The device performs the automatic assignment at following case.

1)When ECC correction performance is increased during read error retry, a read error is recovered.

Before automatic alternate assignment, the device performs rewriting the corrected data to the erred sector and rereading. If no error occurs at rereading, the automatic alternate assignment is not performed.

2)When a write error occurs and the error does not recovered.

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Fujitsu MPE3XXXAT manual Alternate cylinder assignment

MPE3XXXAT specifications

The Fujitsu MPE3XXXAT series is a robust line of hard disk drives (HDDs) known for their reliability, performance, and advanced technology. Designed primarily for enterprise storage solutions, these drives cater to high-demand environments such as data centers, servers, and workstations. With capacities ranging from hundreds of gigabytes to several terabytes, the MPE3XXXAT series offers scalable storage options to accommodate a variety of applications.

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