3.1 Data Space

Cell

Note: This drive manages alternate spare areas for each cell, which is a set of cylinders. One cell consists of 14 cylinders.

Figure 3.2 Spare area in cell

An alternate cylinder is used when spare sectors in a cell are used up or 0 is specified as the number of spare sectors in a cell. 1 cylinder at the end of each zone of the user space is allocated as alternate cylinders as shown in Figure 3.3.

The user space and the CE space share the alternate cylinders.

Zone

Figure 3.3 Alternate cylinder

Note:

The number of alternate cylinders can not be changed.

3.1.3Track format

(1)Physical sector allocation

Figure 3.4 shows the allocation of the physical sectors in a track. The length in bytes of each physical sector and the number of sectors per track vary depending on the logical data block length. The unused area (G4) exists at the end of the track in formats with most logical data block lengths.

The interval of the sector pulse (length of the physical sector) is decided by multiple of 40MHz free running frequency. This clock is not equal to the interval of the byte clock for each zone. Therefore, the physical sector length cannot be described with a byte length.

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Fujitsu MAP3735FC, MAP3147FC manual Data Space, Track format

MAP3735FC, MAP3147FC specifications

Fujitsu has been a prominent player in the hard disk drive market, with its MAP3147FC and MAP3735FC models standing out in terms of performance and reliability. These drives are engineered to meet the growing demands of enterprise applications, providing robust solutions for data storage in critical environments.

The Fujitsu MAP3147FC, with a capacity of 147 GB, is optimized for high-speed data access and storage efficiency. This 3.5-inch SCSI drive operates at a rotational speed of 15,000 RPM, ensuring rapid data retrieval and minimized latency, making it ideal for applications requiring quick transaction processing. It features a 4 Gbps Fibre Channel interface, which enhances connectivity and system integration, promoting seamless communication between devices in storage area networks.

On the other hand, the MAP3735FC model offers a higher capacity of 300 GB. It shares similar specifications with its counterpart, including the 15,000 RPM speed, which guarantees top-notch performance for mission-critical applications. The MAP3735FC, like the MAP3147FC, incorporates advanced technologies such as Command Queuing, which optimizes the execution of multiple read and write commands in a queue. This feature is particularly beneficial in environments with high I/O demands, improving overall system throughput and efficiency.

Both drives utilize sophisticated error correction techniques, ensuring data integrity and reliability. They are equipped with features like S.M.A.R.T. (Self-Monitoring, Analysis, and Reporting Technology), which continuously monitors the health of the drives and helps predict potential failures, allowing for proactive maintenance and data protection.

In terms of physical characteristics, both models are designed to withstand the rigors of continuous operation. They are built with a rugged casing to protect against vibration and shock, making them suitable for use in enterprise-level servers and storage systems. Their design also allows for efficient heat dissipation, which is critical for maintaining optimal performance during extended use.

In summary, Fujitsu's MAP3147FC and MAP3735FC hard drives embody a combination of high speed, reliability, and advanced features tailored for enterprise environments. Their robust performance, large storage capacities, and reliable error correction technologies make them an excellent choice for businesses looking to optimize their data storage solutions and ensure seamless operation in demanding applications. With Fujitsu's commitment to quality and innovation, these models continue to meet the evolving needs of the data storage industry.