3.3Defect Management

3.3.1Defect list

Information of the defect location on the disk is managed by the defect list. The following are defect lists which the IDD manages.

∙P list (Primary defect list): This list consists of defect location information available at the disk drive shipment and is recorded in a system space. The defects in this list are permanent, so the INIT must execute the alternate block allocation using this list when initializing the disk.

∙D list (Data defect list): This list consists of defect location information specified in a FORMAT UNIT command by the INIT at the initialization of the disk. This information is recorded in the system space of the disk drive as the G list. To execute the alternate block allocation, the FORMAT UNIT command must be specified.

∙C list (Certification defect list): This list consists of location information on defective blocks which are detected by the verifying operation (certification) of the data block after the initiation when executing the FORMAT UNIT command. The IDD generates this information when executing the FORMAT UNIT command, and the alternate block allocation is made upon the defective block. This information is recorded in the system space of the disk drive as the G list.

∙G list (Growth defect list): This list consists of defective logical data block location information specified in a REASSIGN BLOCKS command by the INIT, information on defective logical data blocks assigned alternate blocks by means of IDD automatic alternate block allocation, information specified as the D list, and information generated as the C list. They are recorded in the system space on the disk drive.

The INIT can read out the contents of the P and G lists by the READ DEFECT DATA command.

3.3.2Alternate block allocation

The alternate data block is allocated to a defective data block (= sectors) in defective sector units by means of the defect management method inside the IDD.

The INIT can access all logical data blocks in the user space, as long as there is no error.

Spare sectors to which alternate blocks are allocated can be provided in either "spare sectors in a cylinder" or "alternate cylinders". See Subsection 3.1.2 for details.

The INIT can specify the size and area for spare sectors by the MODE SELECT or MODE SELECT EXTENDED command at the time of the initialization of the disk.

Both of the following are applicable to the alternate block allocation.

∙Sector slip treatment: Defective sectors are skipped and the logical data block corresponding to those sectors is allocated to the next physical sectors. This treatment is made on the same cylinder as the defective sector's and is effective until all spare sectors in that cylinder are used up.

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Fujitsu MAG3091FC, MAF3364FC, MAG3182FC manual Defect Management Defect list, Alternate block allocation
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MAG3182FC, MAF3364FC, MAG3091FC specifications

Fujitsu has established itself as a leading provider of storage solutions, with a robust lineup that includes the MAG3182FC, MAG3091FC, and MAF3364FC hard drives. These models cater to the needs of enterprise and data center environments, focusing on reliability, performance, and advanced technology.

The Fujitsu MAG3182FC is a Fibre Channel hard drive designed for high-speed data transfer and optimal storage performance. With a capacity of 18.2 GB, it is built for applications requiring rapid access to data. The drive operates at a spindle speed of 10,000 RPM, ensuring quick data retrieval and low latency. It features a 2 Gbps Fibre Channel interface, which allows for fast communication between the drive and the server, making it ideal for environments that demand high throughput, such as transaction processing and database management.

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