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 ST3450856FC manual Defect and error management, Drive internal defects/errors, Drive error recovery procedures
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ST3450856FC specifications

The Seagate ST3146356FC, ST3300656FC, and ST3450856FC are hard disk drives designed for enterprise storage solutions, showcasing Seagate’s commitment to performance, reliability, and advanced technology in the data storage sector. These drives cater primarily to the needs of data centers and businesses requiring robust data management capabilities.

The ST3146356FC is notable for its 146GB capacity, 3.5-inch form factor, and 10,000 RPM spindle speed. It employs Serial Attached SCSI (SAS) interface technology, which ensures high data transfer rates and reliable connectivity. This model is designed to handle a multitude of demanding applications, such as online transaction processing and enterprise resource planning, requiring fast access to data and minimized latency.

The ST3300656FC, with a capacity of 300GB, continues the trend of high performance set by its predecessor. This drive also features the 10,000 RPM spindle speed and SAS interface, providing enhanced data throughput and optimized performance for intensive workloads. The drive is built with advanced error recovery features that enhance data integrity and reliability, making it suitable for critical applications where data loss is unacceptable.

The ST3450856FC offers even greater capacity, with a robust 450GB storage option. Like the other models, it operates at 10,000 RPM and utilizes the SAS interface. This drive is designed for scalability, ensuring that it can meet the evolving storage demands of enterprises. It is also equipped with sophisticated technologies such as Seagate's Enhanced S.M.A.R.T. (Self-Monitoring, Analysis, and Reporting Technology), providing continual monitoring of the drive’s health and performance metrics.

All three models share key characteristics, including advanced thermal and power management technologies that help maintain optimal operating temperatures and reduce energy consumption. This is crucial in data center environments where maximizing efficiency is vital for operational cost management. Additionally, Seagate's commitment to low acoustic noise levels ensures quieter operation, which is beneficial in environments where sound levels must be controlled.

In summary, the Seagate ST3146356FC, ST3300656FC, and ST3450856FC drives are engineered for enterprise environments demanding high reliability, speed, and capacity. Their advanced technologies, including SAS interface and enhanced error management systems, make these drives ideal for critical applications in data-intensive sectors. With reinforced durability, effectiveness in managing large volumes of data, and a focus on energy efficiency, these drives symbolize the pinnacle of Seagate's storage innovations for enterprise solutions.
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