2.1 Data Buffer

6)When transfer of all the specified data is completed, the IDD reports the status and terminates the command.

Note:

In order to avoid frequent repetition of the disconnect/reconnect processing after data transfer starts on the SCSI bus, and avoid the occurrence of data overruns, it is necessary to set the buffer full ratio (see Section 2.1.2) of the MODE SELECT parameter so the difference in the data transfer rates between the INIT (SCSI bus) and the disk drive is maintained in a good balance.

Figure 2.2 shows an example of the data buffer operating state during a read operation. Details are explained in Section 2.1.2.

Sector

Disk

Amount of Data

in the Buffer

Buffer Full Ratio

SCSI Bus

DATA IN

Reconnection

Data Storage Completion Wait

Figure 2.2 Example of data buffer operation during read

(2)Write operation

After data transferred from the INIT are stored temporarily in the data buffer, they are written to the disk media. The basic write operation procedure is as shown below.

1)When the IDD receives a command and disconnects, it immediately reconnects and enters the DATA OUT phase and stores data transferred from the INIT to the data buffer (data pre-fetch). At this time, the IDD locates the position of the data block on the disk media specified by the command in parallel.

When storing of all the data specified in the command in the data buffer is completed, or if the empty space in the data buffer is all filled during data storage due to the volume of the specified data, the IDD performs disconnect processing and disconnects from the SCSI bus.

2)When locating of the target data block on the disk media is completed, the IDD writes the data in the data buffer to the disk media. If the target data block location operation is completed during the data pre-fetch processing in 1), writing of data to the disk media is performed in parallel with the data pre-fetch to the data buffer.

C141-E167

2 - 3

Page 52 Page 54
Page 53
Image 53
Fujitsu MAP3735, MAP3367, MAP3147, MAS3735, MAS3367 specifications Data Buffer, Example of data buffer operation during read
Page 52 Page 54

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.
Top Page Image Contents