10.0Defect 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 SAS system error considerations (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 10.4)

Media Pre-Scan (see Section 10.5)

Deferred Auto-Reallocation (see Section 10.6)

Idle Read After Write (see Section 10.7)

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

10.1Drive 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 SAS Interface Manual. Also, more information on the drive Error Recovery philosophy is presented in the SAS Interface Manual.

10.2Drive 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 SCSI 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 consist of 20 levels for read recoveries and six levels for write. Each level may consist of multiple steps, where a step is defined as a recovery function involving a single re- read or re-write attempt. The maximum level used by the drive in LBA recovery is determined by the read and write retry counts.

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Seagate ST9450205SS manual Defect and error management, Drive internal defects/errors, Drive error recovery procedures

ST9600005SS, ST9600205SS, ST9300505SS, ST9300605SS, ST9300405SS specifications

Seagate has long been a prominent player in the storage solutions market, offering a range of hard drives that cater to various needs and applications. Among its extensive lineup, the Seagate ST9600105SS, ST9450405SS, ST9450305SS, ST9900605SS, and ST9900805SS stand out due to their unique features and robust performance, making them suitable for both personal and professional use.

The Seagate ST9600105SS is a 2.5-inch 600GB SAS hard drive that delivers exceptional reliability and performance. With a rotational speed of 10,000 RPM, this drive ensures quick data access through its enhanced data transfer rate. It utilizes a SAS 6Gb/s interface, allowing for fast and efficient data management in enterprise environments. The drive is designed with Seagate's AgileArray technology, which optimizes drive reliability for multi-drive environments, ensuring that users benefit from reduced downtime.

Similarly, the ST9450405SS and ST9450305SS are also 2.5-inch SAS drives, offering capacities of 450GB and 300GB, respectively. Both models feature a 10,000 RPM speed and a 6Gb/s SAS interface, making them ideal for use in data centers and business-critical applications. The ST9450405SS has enhanced power efficiency, aiding in lowering operational costs for enterprises. Both drives incorporate Seagate's advanced error recovery controls, which help maintain data integrity under varying workloads.

On the larger capacity side, the Seagate ST9900605SS and ST9900805SS drives provide even more storage options. Offering 600GB and 800GB capacities, respectively, these drives are designed for high-performance computing environments. They also spin at 10,000 RPM and support the 6Gb/s SAS interface. The ST9900805SS, in particular, is noted for its advanced performance in transactional workloads, making it suitable for database storage, virtualization, and analytics.

All five models feature Seagate’s innovative technologies, including firmware enhancements for improved error correction and reliability. They are also built to operate in a variety of environments, offering robust vibration tolerance.

In summary, the Seagate ST9600105SS, ST9450405SS, ST9450305SS, ST9900605SS, and ST9900805SS represent some of the best storage solutions for high-demand applications. With their emphasis on performance, reliability, and energy efficiency, these drives are engineered to meet the challenges of modern data storage needs, ensuring organizations can rely on them for their critical operations.