Sense Data Error Recovery Methods

Remark:

1.When this function is specified (ARRE = "1"), the EER flag's specification in the MODE SELECT parameter is made invalid and Read retry processing is performed up to the number of times specified in the "Number of Retries during Read" parameter. If "0" is specified in the DCR flag, correction processing of the data is performed afterward (see Section 5.3.1 (3)). When "1" is specified in the DCR flag, ECC correction processing is prohibited, so even if "1" is specified in the ARRE flag, auto alternate block allocation processing will not be executed for errors in the data area.

2.When errors in the data area are recovered from by ECC correction processing, before implementing alternate block allocation processing, rewriting of the recovered data and a verify check (rereading) are performed. If data are recovered by rewriting, alternate block allocation of that data block is not performed.

3.When a write operation is prohibited through the setting terminal, the auto alternate block allocation processing specification is disabled.

(2)Auto alternate block allocation processing during a write operation 1

This function is enabled by specifying "1" in the AWRE flag in the MODE SELECT parameters. Furthermore, this function is applicable to the following commands only.

•WRITE command

•WRITE EXTENDED command

•WRITE AND VERIFY

When this function is permitted, if, during read processing to the data area, up to 8 unrecoverable read errors will be logged by the drive. The log will be checked before every WRITE command.

If a WRITE command has the same LBA in the log, then Sector Size +2 bytes of data will be written to the sector, and it will be verified with less powered ECC. If the verify is successful, then the AWRE will not be performed. (no sense will be reported).

If the verify is unsuccessful, then check the spare. Write the data onto the new spare, and verify it. If the verify is successful, then the reallocation will be proceeded. If the verify is unsuccessful, then the drive will add the defective spare onto the G-List, and then choose another spare, and try the same thing to the new spare until the verify completes successfully. After reallocates all of the logged LBA included in a WRITE command the drive will start the write operation.

(3)Auto alternate block allocation processing during a write operation 2

This function is enabled by specifying "1" in the AWRE flag in the MODE SELECT parameters. Furthermore, this function is applicable to the following commands only.

•WRITE command

•WRITE EXTENDED command

When this function is permitted, if, during WRITE/WRITE EXTENDED command detects any Servo error (e.g. Write offtrack error) and cannot be recovered within pre-determined retry number (specified in Mode Parameter). For the sectors around defective Servo, alternate blocks are allocated and the data of this WRITE commands are re-written.

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Fujitsu MAP3735, MAP3367, MAP3147, MAS3735, MAS3367 specifications Remark
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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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