7.0Defect and error management

Seagate continues to use innovative technologies to manage defects and errors. These technologies are designed to increase data integrity, perform drive self-maintenance, and validate proper drive operation.

SCSI defect and error management involves drive internal defect/error management and FC system error con- siderations (errors in communications between the initiator and the drive). In addition, Seagate provides the following technologies used to increase data integrity and drive reliability:

•Background Media Scan (see Section 7.4)

•Media Pre-Scan (see Section 7.5)

•Deferred Auto-Reallocation (see Section 7.6)

•Idle Read After Write (see Section 7.7)

The read error rates and specified storage capacities are not dependent on host (initiator) defect management routines.

7.1Drive internal defects/errors

During the initial drive format operation at the factory, media defects are identified, tagged as being unusable, and their locations recorded on the drive primary defects list (referred to as the “P’ list and also as the ETF defect list). At factory format time, these known defects are also reallocated, that is, reassigned to a new place on the medium and the location listed in the defects reallocation table. The “P” list is not altered after factory formatting. Locations of defects found and reallocated during error recovery procedures after drive shipment are listed in the “G” list (defects growth list). The “P” and “G” lists may be referenced by the initiator using the Read Defect Data command.

Details of the SCSI commands supported by the drive are described in the Fibre Channel Interface Manual. Also, more information on the drive Error Recovery philosophy is presented in the Fibre Channel Interface Manual.

7.2Drive error recovery procedures

When an error occurs during drive operation, the drive, if programmed to do so, performs error recovery proce- dures to attempt to recover the data. The error recovery procedures used depend on the options previously set in the Error Recovery Parameters mode page. Error recovery and defect management may involve using sev- eral SCSI commands described in the Fibre Channel Interface Manual. The drive implements selectable error recovery time limits required in video applications.

The error recovery scheme supported by the drive provides a way to control the total error recovery time for the entire command in addition to controlling the recovery level for a single LBA. The total amount of time spent in error recovery for a command can be limited using the Recovery Time Limit bytes in the Error Recovery mode page. The total amount of time spent in error recovery for a single LBA can be limited using the Read Retry Count or Write Retry Count bytes in the Error Recovery mode page.

The drive firmware error recovery algorithms consists of 13 levels for read recoveries and five levels for write. Each level may consist of multiple steps, where a step is defined as a recovery function involving a single re-

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Seagate ST3300056FC (FDE) Defect and error management, Drive internal defects/errors, Drive error recovery procedures
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ST3450056FC (FDE), ST3146756FC (FDE), ST3300056FC (FDE) specifications

Seagate has established itself as a leader in data storage solutions, and among its high-performance offerings are the Seagate ST3300056FC (FDE), ST3146756FC (FDE), and ST3450056FC (FDE) drives. These drives are part of Seagate's enterprise-class, 3.5-inch form factor family, providing robust data security, reliability, and performance for demanding data center environments.

The ST3300056FC boasts a capacity of 3TB, making it ideal for applications that require substantial storage space. With a 7200 RPM spindle speed and a 6Gb/s Serial Attached SCSI (SAS) interface, this drive delivers rapid data access speeds and high throughput, catering to the needs of enterprise workflows and data-intensive applications. The FDE (Full Disk Encryption) feature ensures that all stored data is encrypted, providing an added layer of protection against unauthorized access, which is critical for businesses handling sensitive information.

Similarly, the ST3146756FC offers a 1.4TB capacity, also spinning at 7200 RPM and utilizing a 6Gb/s SAS interface. As with its counterpart, this drive incorporates FDE technology, making it an excellent choice for environments that prioritize data security while maintaining performance. The SAS interface enhances connectivity options and further improves reliability and data integrity, essential for mission-critical applications.

The ST3450056FC, with a capacity of 4.5TB, stands out as a powerful option for storage needs that exceed traditional offerings. With the same 7200 RPM spindle speed and 6Gb/s SAS interface, it ensures optimal performance across various workloads. The FDE functionality further enhances its appeal, making it suitable for organizations that must comply with stringent data protection regulations.

All three drives are built with Seagate's advanced technologies, including PowerBalance, which maximizes the spindle performance while optimizing power consumption and thermal management. They are also designed with vibration tolerance, enhancing their reliability in multi-drive systems and environments where space and airflow may be limited.

In summary, the Seagate ST3300056FC, ST3146756FC, and ST3450056FC drives exemplify cutting-edge engineering, catering to enterprise needs with their impressive capacities, robust performance, and built-in security. They are well-suited for organizations that prioritize reliability and data integrity, making them a vital component of modern storage infrastructures.
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