Command Processing

1.8.2Logical block addressing

The IDD uses logical data block addressing which is not dependent on the disk drive’s physical structure as the method of data access on the disk medium. The IDD makes correspondence between each physical sector and each logical data clock address during formatting. Access to the data on the disk medium is performed in logical data block units and the INIT specifies the logical data block address that is its object during access.

In logical data block addressing, specifying of a data block address is a function which specifies 2 continuous binary numbers for each drive. Furthermore, the INIT can know the logical data block address range in the user space where specification is possible using the READ CAPACITY command.

(1)User space logical block addresses

The top data block in the user space is made logical data block address “0,” then continuous logical data block addresses are allocated to each data block until the last data block in the user space.

The IDD makes cylinder 0, track 0 sector 0 the top logical data block, and allocates subsequent logical data blocks in the order described below to addresses in ascending order.

1)Within the same track, logical data blocks are allocated to sector numbers in ascending order.

2)Within the same head of the same cell, succeeding logical data blocks are allocated to the sectors in each track according to 1) in the ascending order of cylinder numbers.

3)Within the next head of the same cell, succeeding logical data blocks are allocated to the sectors in each track according to 1) and 2) in the ascending order of track numbers.

4)On the last track inside the same cell, succeeding logical data blocks are allocated to sectors except for spare sectors according to 1).

5)After all the allocation in 1) to 4) is completed within the same cell, succeeding logical data blocks are allocated to the next cell beginning with track 0, according to 1) to 3), and so on to each cell number in ascending order until the last cell in each zone (refer to alternate cell b-1 in Figure 1.5) in the user space, with the exception of alternate cells.

(2)Alternate area

The alternate area in user space (spare sectors within each cell and alternate cells) are excluded from the abovementioned logical data block addresses. Access to allocated sectors as alternate blocks within the alternate area is performed automatically by the IDD’s defect management (sector slip processing and alternate block processing), so it is not particularly necessary for the user to access the alternate area. Also, data blocks in the alternate area cannot be clearly specified and accessed directly.

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Fujitsu MAP3367, MAP3147, MAS3735, MAP3735, MAS3367 specifications Logical block addressing
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MAP3735, MAP3147, MAS3367, MAP3367, MAS3735 specifications

Fujitsu, a renowned leader in technology and innovation, has developed a variety of reliable hard disk drives (HDDs) that cater to a wide range of data storage needs. Among these, the MAS3735, MAP3367, MAS3367, MAP3147, and MAP3735 series stand out for their advanced features and exceptional performance.

The MAS3735 is a high-capacity enterprise-class drive that boasts a storage capacity of up to 300 GB. Its 10,000 RPM spindle speed ensures rapid data retrieval and efficient performance, making it ideal for data-intensive applications. It utilizes a Serial Attach SCSI (SAS) interface, which allows for improved data transfer rates and increased reliability compared to traditional SATA drives. The drive is designed with advanced technologies such as error recovery and data integrity features, ensuring the safety and security of critical data.

Similarly, the MAP3367 and MAS3367 models are geared towards both enterprise and mid-range server environments, providing a storage capacity of up to 300 GB as well. These drives also operate at a spindle speed of 15,000 RPM, offering swift access times that enhance overall system performance. The MAP3367 employs the Ultra 320 SCSI interface, allowing for significant bandwidth and ensuring data is transmitted efficiently.

On the other hand, both MAP3147 and MAP3735 models provide versatile solutions for various applications, supporting capacities from 36 GB to 147 GB. The MAP3147, with its 10,000 RPM speed, is optimized for workloads requiring quick access and high throughput, making it suitable for transactional systems and enterprise applications. The MAP3735, while offering comparable capacity, emphasizes exceptional reliability and durability, which is crucial for environments that involve heavy data loads.

All these Fujitsu HDDs are characterized by their robust construction, reliability, and efficiency. They are built to withstand heavy workloads and are equipped with features like advanced thermal management and acoustic noise reduction, ensuring they operate effectively in data center environments.

In conclusion, Fujitsu's MAS3735, MAP3367, MAS3367, MAP3147, and MAP3735 series HDDs are designed for high performance and reliability, catering to both enterprise and mid-range environments. Their advanced features make them a strong choice for businesses looking to enhance their storage solutions while maintaining data integrity and system performance.
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