Manuals / Seagate / Lawn and Garden / Brush Cutter

Seagate ST3146707LW/LC, ST3300007LW/LC manual Defect and error management, Drive internal defects

Models: ST3300007LW/LC ST373207LW/LC ST3146707LW/LC

1 110
Download 110 pages 16.38 Kb
Page 51
Image 51

7.0Defect and error management

The drive, as delivered, complies with this specification. The read error rate and specified storage capacity are not dependent upon use of defect management routines by the host (initiator).

Defect and error management in the SCSI system involves the drive internal defect/error management and SCSI systems error considerations (errors in communications between Initiator and the drive). Tools for use in designing a defect/error management plan are briefly outlined in this section, with references to other sections where further details are given.

7.1Drive internal defects

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 (see the SCSI Interface Product Manual).

7.2Drive error recovery procedures

Whenever an error occurs during drive operation, the drive, if programmed to do so, performs error recovery procedures to attempt to recover the data. The error recovery procedures used depend on the options previ- ously set up in the error recovery parameters mode page. Error recovery and defect management may involve the use of several SCSI commands, the details of which are described in the SCSI Interface Product Manual. The drive implements selectable error recovery time limits such as are required in video applications. For addi- tional information on this, refer to the Error Recovery Page table in the SCSI Interface Product Manual, which describes the Mode Select/Mode Sense Error Recovery parameters.

The error recovery scheme supported by the drive provides a means 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 via 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 via the Read Retry Count or Write Retry Count bytes in the Error Recovery Mode Page.

The drive firmware error recovery algorithms consist of 11 levels for read recoveries and 5 levels for writes.

Table 3 equates the Read and Write Retry Count with the maximum possible recovery time for read and write recovery of individual LBAs. The times given do not include time taken to perform reallocations, if reallocations are performed. Reallocations are performed when the ARRE bit (for reads) or AWRE bit (for writes) is one, the RC bit is zero, and the Recovery Time Limit for the command has not yet been met. Time needed to perform reallocation is not counted against the Recovery Time Limit.

The Read Continuous (RC) bit, when set to one, requests the disc drive to transfer the requested data length without adding delays (for retries or ECC correction) that may be required to insure data integrity. The disc drive may send erroneous data in order to maintain the continuous flow of data. The RC bit should only be

Cheetah 10K.7 SCSI Product Manual, Rev. D

41

Page 50 Page 52
Page 51
Image 51
Seagate ST3146707LW/LC, ST373207LW/LC Defect and error management, Drive internal defects, Drive error recovery procedures
Page 50 Page 52

ST3300007LW/LC, ST373207LW/LC, ST3146707LW/LC specifications

Seagate's ST3146707LW/LC, ST373207LW/LC, and ST3300007LW/LC are part of the company's renowned line of hard disk drives (HDDs), specifically designed for enterprise and high-performance computing environments. With their reliability and performance, these drives have become popular choices for data centers and critical applications requiring extensive storage capabilities.

One of the standout features of these models is their capacity to handle large volumes of data. The ST3146707LW/LC has a capacity of 146GB, while the ST373207LW/LC offers 73GB, and the ST3300007LW/LC comes with a substantial 300GB. These capacities make them well-suited for applications that require not only high storage space but also rapid access to data.

In terms of performance, these drives utilize a 10,000 RPM spindle speed, which significantly enhances data access times and overall performance. The combination of fast rotational speeds with Seagate's advanced caching algorithms allows for swift data retrieval, making these drives ideal for environments where speed is crucial.

These HDDs also employ the SCSI (Small Computer System Interface) interface, which promises high data transfer rates and reliability in enterprise-level applications. The Ultra320 SCSI interface can support transfer rates up to 320 MB/s, ensuring that the drives can efficiently communicate with other system components.

Another key technology featured in these models is Seagate's Adaptive Error Correction technology, which enhances data integrity and reliability. This feature helps in the detection and correction of errors that can occur during data transfer, reducing the risk of data loss.

Performance consistency is critical in enterprise environments, and these drives are built to endure the demands of 24/7 operation. They are designed with robust mechanisms to withstand temperature fluctuations, shock, and vibrations commonly found in data center settings.

In summary, the Seagate ST3146707LW/LC, ST373207LW/LC, and ST3300007LW/LC hard drives exemplify advanced features and technologies tailored for enterprise storage solutions. With significant capacities, impressive spindle speeds, SCSI connectivity, and reliability-focused technologies, these drives remain a valuable asset for businesses relying on stable and high-performance data storage.