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Fujitsu MAP3367NC/NP, MAP3147NC/NP manual Defect Management Defect list, Alternate block allocation

Models: MAP3735NC/NP MAP3367NC/NP MAP3147NC/NP

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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.

•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 cell" 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 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 cell as the defective sector's and is effective until all spare sectors in that cell are used up.

•Alternate sector treatment: The logical data block corresponding to defective sectors is allocated to unused spare sectors in the same cell or unused spare sectors in the alternate cylinder.

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Fujitsu MAP3367NC/NP, MAP3147NC/NP, MAP3735NC/NP manual Defect Management Defect list, Alternate block allocation
Page 46 Page 48

MAP3735NC/NP, MAP3367NC/NP, MAP3147NC/NP specifications

Fujitsu's MAP3147NC/NP, MAP3367NC/NP, and MAP3735NC/NP hard disk drives represent a robust solution for businesses seeking reliable data storage options. These models are part of Fujitsu’s extensive line of high-performance hard drives that cater to various organizational needs, from servers to high-capacity data storage systems.

One of the standout features of these hard drives is their speed. The MAP3147NC/NP operates at a spindle speed of 10,000 RPM, ensuring rapid data access and retrieval. This speed is essential for environments requiring quick data transactions, making it suitable for enterprise-level databases and high-performance computing applications.

The capacity range across these models is designed to meet varying storage requirements. The MAP3147NC offers 147 GB, while the MAP3367NC provides 67 GB, and the MAP3735NC boasts a generous capacity of 35 GB. This diversity allows organizations to select the drive that best fits their data storage and performance needs while maintaining a scalable storage solution.

In terms of technology, the drives incorporate advanced features such as Serial Attached SCSI (SAS) interface, which enhances data throughput and reliability compared to traditional Parallel SCSI interfaces. SAS technology enables these drives to support multiple device connections while ensuring high-performance throughput, essential for modern enterprise environments.

The drives employ a 64 MB cache, providing a significant performance boost by allowing for quicker access to frequently used data. This capability improves overall system responsiveness, especially in applications requiring high input/output operations per second (IOPS).

Moreover, the MAP3147NC/NP, MAP3367NC/NP, and MAP3735NC/NP series are designed with data integrity in mind. They include features such as Error Correction Code (ECC) and background error scanning, which work together to maintain the integrity of stored data and minimize the risk of data loss.

In conclusion, Fujitsu’s MAP3147NC/NP, MAP3367NC/NP, and MAP3735NC/NP hard disk drives provide a blend of performance, capacity, and reliability. With their fast spindle speeds, robust data throughput via SAS technology, and enhanced cache memory, these drives are ideal for enterprises requiring durable and efficient data storage solutions in high-demand environments. As organization needs evolve, these drives offer scalability and reliability to support diverse applications and workloads.