3.1 Control/Sense Commands

3.1.3READ CAPACITY (25)

 

Bit

7

6

5

 

4

3

 

2

1

0

Byte

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0

 

 

 

 

X‘25’

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1

 

 

LUN

 

 

0

0

 

0

0

0

 

 

 

 

 

 

 

 

 

2

 

 

 

 

Logical Block Address (MSB)

 

 

 

 

 

 

 

 

 

 

 

3

 

 

 

 

Logical Block Address

 

 

 

 

 

 

 

 

 

 

 

 

4

 

 

 

 

Logical Block Address

 

 

 

 

 

 

 

 

 

 

 

 

5

 

 

 

 

Logical Block Address (LSB)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

6

 

0

0

0

0

0

 

0

0

0

 

 

 

 

 

 

 

 

 

 

 

7

 

0

0

0

0

0

 

0

0

0

 

 

 

 

 

 

 

 

 

 

 

8

 

0

0

0

0

0

 

0

0

PMI

 

 

 

 

 

 

 

 

 

 

 

9

 

0

0

0

0

0

 

0

0

Link

 

 

 

 

 

 

 

 

 

 

 

 

This command transfers information related to the disk drive's capacity and the data block size to the INIT.

When bit 0 "PMI (partial medium indicator)" of CDB byte 8 is "0," the logical block address and block length (byte length) of the final data block which is accessible in the disk drive (user space) are transferred to the INIT. At this time, the "Logical Block address" field in the CDB must specify zero.

When the "PMI" bit is "1," the logical block address and block length (byte length) of data blocks which satisfy either of the following conditions is transferred to the INIT.

The data block on the track where the specified block exists, which is just before the block where the first alternate sector processing (not including defective block sector slip processing) is implemented. However, when alternate sector processing is being implemented in the specified block, the data block specified in the CDB.

When no alternate sector processed data block exists in the track where the specified block exists, the last data block in that track.

By using this command with the "PMI" bit specified as "1", the INIT can search for usable data space continuously without being interrupted by data transfers for alternate sector processing or switching of track.

The format of the data transferred to the INIT by this command is shown in Figure 3.6.

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Image 75
Fujitsu MAP3367, MAP3147, MAS3735, MAP3735, MAS3367 specifications Read Capacity, Pmi

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.

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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.