Data Format

Type 2 (Reassignment of write fail sector)

1)Commands to be applied

-WRITE

-WRITE EXTENDED

-FORMAT UNIT

-WRITE at executing WRITE AND VERIFY

2)Application requirements / processing

When 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.

Sectors to be made AWRE shall be following:

-the sector where the error occurs and the latter sectors and,

-the sectors whose data are logically continual and stored in Cache,

-the sectors which will be processed in this Write command and,

-the sectors which locate between erroneous Servo -1 and +1 (including Split sector)

This function is also applied for the sector that has already been re-assigned. Remark:

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

Automatic alternate block allocation is made up to the following quantities during the execution of one command:

ARRE = Twice

AWRE (Type 1) = Eight times

AWRE (Type 2) = Maximum number which can be processed within the recovery time limit

If more than the above mentioned defective block is detected, the alternate block assignment processing for the first defective block is executed but the alternate block assignment processing for the second one is not executed and the command being executed terminates. However, the initiator can recover the twice error by issuing the same command again.

When an error is detected in a data block in the data area, recovery data is rewritten and verified in automatic alternate block allocation during the execution of the READ or READ EXTENDED command. Alternate block allocation will not be made for the data block if recovery is successful.

Example: Even if the data error which is recoverable by the WRITE LONG command is simulated, automatic alternate block allocation will not be made for the data block.

3-14

C141-E235

Page 52
Image 52
Fujitsu MAW3147FC, MAW3300FC, MAW3073fc manual Write Write Extended Format Unit

MAW3073fc, MAW3147FC, MAW3300FC specifications

The Fujitsu MAW3073fc, MAW3300FC, and MAW3147FC are high-performance Fibre Channel hard disk drives that cater to enterprise storage solutions. Designed for demanding applications, these drives are engineered to deliver reliability, speed, and capacity, making them suitable for data centers and other high-availability environments.

The MAW3073fc offers a storage capacity of 73GB and operates at 15,000 RPM, ensuring rapid data access and high throughput. This drive features advanced error correction capabilities, enhancing data integrity while minimizing downtime. The MAW3073fc supports the Fibre Channel interface, enabling fast data transfer rates that are essential for high-performance computing scenarios.

Following this, the MAW3300FC steps up the game with a larger capacity of 300GB, also spinning at 15,000 RPM. It boasts enhanced reliability features, including improved thermal management and vibration tolerance, which significantly reduce wear and tear and prolong the drives' lifespan. Its hot-swappable design allows for easy maintenance, making it an ideal choice for critical applications that require minimal disruptions.

The MAW3147FC further expands the offering with a storage capacity of 147GB. Designed for applications that require a balance between performance and capacity, this drive provides a reliable solution for enterprise environments. Like its counterparts, it operates at 15,000 RPM, ensuring swift data retrieval and consistency under heavy loads. The MAW3147FC also implements sophisticated caching algorithms that optimize read and write performance.

All three drives utilize SCSI command sets and feature RAID support, making them compatible with various enterprise storage systems. These drives are built with enterprise-grade components, ensuring durability and reliability, crucial in mission-critical setups. The combination of high RPM speeds, reliability features, and large capacities makes the Fujitsu MAW series an excellent choice for organizations looking to enhance their storage infrastructure.

In terms of technologies, these drives use advanced servo technology and tight mechanical tolerances to achieve high precision and performance. Moreover, they are designed to operate in environments with rigorous temperature and humidity controls, further enhancing their reliability. The MAW series exemplifies Fujitsu's commitment to providing high-quality, performance-driven storage solutions for modern enterprise needs.