Seagate ST3300457SS, ST3450657SS manual Defect and error management, Drive internal defects/errors

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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 SAS 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- read or re-write attempt. The maximum level used by the drive in LBA recovery is determined by the read and write retry counts.

Cheetah 15K.7 SAS Product Manual, Rev. D

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Contents ST3450657SS ST3600857SSST3300457SS Standard models Self-Encrypting Drive modelsPage Contents Installation Defect and error managementAbout Fips About self-encrypting drives Interface requirementsPower Cheetah 15K.7 SAS Product Manual, Rev. D Seagate Online Support and Services Seagate Technology support servicesScope Standards Standards, compliance and reference documentsElectromagnetic compatibility Electromagnetic susceptibilityEuropean Union Restriction of Hazardous Substances RoHS ComplianceReference documents General description Standard features Media descriptionPerformance Reliability Factory-installed optionsFormatted capacities Programmable drive capacityInternal drive characteristics Performance characteristicsAccess time Seek timeFormat command execution time minutes General performance characteristicsStart/stop time Cache operation Prefetch/multi-segmented cache controlPrefetch operation Caching write dataError rates Reliability specificationsRecoverable Errors Unrecoverable ErrorsSeek errors Reliability and serviceInterface errors Preventive maintenanceControlling S.M.A.R.T 4 S.M.A.R.TPerformance impact MillisecondsDetermining rate Reporting controlPredictive failures Thermal monitorState of the drive prior to testing Temperature Log Page 0Dh Parameter Code DescriptionDrive Self Test DST DST failure definitionShort and extended tests Invoking DSTShort test Function Code 001b Extended test Function Code 010bAbort Product warrantyShipping Product repair and return informationPhysical/electrical specifications AC power requirementsDC power requirements Gbit mode Amps 600 GB DC power requirements450 GB DC power requirements 300 GB DC power requirements Power sequencing Conducted noise immunityCurrent profiles Typical 600GB current profiles Typical 300GB current profiles Power dissipation 450GB model Environmental limits Temperature a. OperatingEffective altitude sea level a. Operating Relative humidityShock and vibration ShockPackage size Packaged/product weight Drop height Recommended mounting Vibration a. Operating-normalAcoustics Air cleanlinessCorrosive environment RoHS compliance statementUnits of Measure mm inches Mechanical specificationsAbout Fips PurposeLevel 2 security Admin SP Controlled accessAbout self-encrypting drives Data encryptionRandom number generator RNG Authenticated firmware downloadDrive locking Data bandsSupported commands Power requirementsDefect and error management Drive internal defects/errorsDrive error recovery procedures Page Background Media Scan SAS system errorsMedia Pre-Scan Deferred Auto-ReallocationIdle Read After Write Installation Drive orientationCooling Grounding Drive mountingInterface requirements SAS featuresScsi commands supported Commands supported by Cheetah 15K.6 SAS family drivesDual port support Commands supported by Cheetah 15K.6 SAS family drives Commands supported by Cheetah 15K.6 SAS family drives Commands supported by Cheetah 15K.6 SAS family drives Cheetah 15K.7 inquiry data Bytes Data hex Inquiry dataMode Sense data Mode Pages 12.3.2.1 600GBmodel Mode Sense dataDEF CHG Mode Data Header Block Descriptor Mode Pages 12.3.2.2 450GB model Mode Sense dataDEF CHG Read Capacity Data Buffer C D E F Mode Pages 12.3.2.3 300GB model Mode Sense dataMiscellaneous features Miscellaneous operating features and conditionsSAS physical interface Miscellaneous statusDatum B Connector requirements Physical characteristicsElectrical description Pin descriptionsSAS pin descriptions Power Signal characteristicsSAS transmitters and receivers Ready LED OutLED drive signal SAS-2 Specification complianceDifferential signals General interface characteristicsCheetah 15K.7 SAS Product Manual, Rev. D Numerics IndexPage SAS Smart
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