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.

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Seagate ST3300655FC manual Defect and error management, Drive internal defects/errors, Drive error recovery procedures
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ST3146855FC, ST373455FC, ST3300655FC specifications

Seagate is renowned for its commitment to high-performance data storage solutions, and their range of enterprise drives, including the ST3300655FC, ST373455FC, and ST3146855FC, demonstrates this dedication. These models cater to businesses requiring robust, reliable, and efficient hard disk drives (HDDs) designed for demanding environments.

The ST3300655FC offers a capacity of 300 GB, making it suitable for a variety of enterprise applications. It utilizes a 15,000 RPM spindle speed, which significantly enhances its performance, delivering quick read and write times. This drive supports Serial Attached SCSI (SAS) interface, ensuring faster data transfer rates and reliability essential for critical computing environments. The dual-port connectivity of SAS allows for enhanced fault tolerance and redundancy, making the ST3300655FC ideal for data centers and enterprise storage systems.

Following closely, the ST373455FC provides a slightly larger capacity of 734 GB while maintaining the same 15,000 RPM speed. This drive's design focuses on high availability, making it an excellent choice for applications that require continuous uptime. Like its counterpart, it also benefits from the SAS interface, ensuring that data can be accessed quickly and reliably. The robust construction of the ST373455FC guarantees consistent performance under heavy workloads, an essential characteristic for enterprise use.

The ST3146855FC, with a capacity of 146 GB, offers a balance between speed and storage for enterprises that do not require the larger capacities provided by the other two models. It also operates at 15,000 RPM, benefiting from similar technological advancements as the ST3300655FC and ST373455FC. This drive maintains compatibility with existing systems, making it a versatile option for organizations looking to upgrade their storage solutions without overhauling their infrastructure.

All three models exhibit Seagate's commitment to durability and low power consumption, which is critical for reducing operational costs in data centers. They also feature advanced error recovery and data integrity technologies, ensuring that critical data remains intact and accessible. Enhanced thermal and vibration tolerance further extends the lifespan of these drives in challenging environments.

In summary, the Seagate ST3300655FC, ST373455FC, and ST3146855FC are tailored to meet the rigorous demands of enterprise environments. Their high spindle speeds, SAS connectivity, and robust designs make them exemplary choices for businesses seeking reliable and efficient storage solutions. Their distinctive features and technologies ensure that they deliver outstanding performance, data integrity, and durability, making them invaluable assets in any data-driven organization.
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