3.4 Maintenance, Diagnostic Commands

The “Transfer byte length” field in the CDB specifies the total number of bytes of header and buffer data that can be received by the INIT. The IDD reads the data from the data buffer beginning from the byte position in the data buffer specified in the “Buffer offset” field of the CDB and continuing in order, then adds the 4-byte header to it and transfers it to the INIT. Data transfer is completed at the point when the number of bytes of the header and data from the IDD’s data buffer, specified in the “Transfer byte length” field, has been transferred, or at the point when transfer of the header and all the data in the IDD’s data buffer, to the final byte position, has been completed. When zero is specified in the “Transfer byte length” field, this command is terminated without executing a data transfer.

The format and contents of the 4-byte header transferred in this mode are the same as in the case of Mode = 0, 0, 0, 0. However, the “Effective buffer data length” field in the header indicates the size (byte length) of the data from the byte position in the data buffer specified in the “Buffer offset” field in the CDB to the final byte position in the data buffer, including that byte. Also, the length of the buffer data transferred to the INIT by this command is the value for the number of bytes in the [“Transfer byte length” field in the CDB – 4 bytes] or the value indicated in the “Effective buffer data length” in the header, whichever is smaller.

(3)Mode = 0, 0, 1, 0: Data only, with address specification

The data transferred to the INIT when this mode is specified is only the data which the IDD reads from the data buffer. The header is not transferred as it is in Mode = 0,0,0,0 and Mode = 0,0,0,1. In this mode, address in the data buffer can be specified in the “Buffer offset” field in the CDB.

The “Transfer byte length” field in the CDB specifies the total number of bytes of buffer data that can be received by the INIT. The IDD reads the data in order beginning from the byte position in the data buffer specified in the “Buffer address” field and transfers it to the INIT. Data transfer is completed at the point when the number of bytes of buffer data specified in the “Transfer byte length” field has been completed or transfer of the buffer data to the final byte position of the IDD’s data buffer is completed. When zero is specified in the “Transfer byte length” field, this command is terminated without executing a data transfer.

(4)Mode = 0, 0, 1, 1: Buffer descriptor

When this mode is specified, the IDD transfers only the 4-byte buffer descriptor to the INIT. the IDD’s data buffer attributes are indicated in the 4-byte buffer descriptor. Zero must be specified in the “Buffer offset” field in the CDB when this mode is specified. The IDD transfers the data length specified in the “Transfer byte length” field in the CDB or 4 bytes, whichever portion of data is smaller, to the INIT. When zero is specified in the “Transfer byte length” field, this command is terminated without executing a data transfer.

Bit

Byte

7

6

5

4

 

 

 

3

2

1

 

 

 

0

0

X’02’ Addressing Boundary

1

X’78’ Buffer Capacity (MSB)

2

X’00’ Buffer Capacity

3

X’00’ Buffer Capacity (LSB)

Figure 3.26 READ BUFFER command: buffer descriptor

C141-E167

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Fujitsu MAP3147, MAP3367, MAS3735, MAP3735, MAS3367 specifications Read Buffer command buffer descriptor
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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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