Seagate ST3450802SS, ST3600002SS manual Defect and error management, Drive internal defects/errors

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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 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 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 SAS Interface Manual. Also, more information on the drive Error Recovery philosophy is presented in the SAS 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 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 11 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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Cheetah NS 10K.2 SAS Product Manual, Rev. C

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Contents Cheetah NS 10K.2 SAS ST3600002SS ST3450802SSPage Contents Seagate Technology support services Defect and error managementInstallation Interface requirementsScope Electromagnetic compatibility Standards, compliance and reference documentsStandards Electromagnetic susceptibilityCompliance Reference documents General description Performance Standard featuresMedia description ReliabilityFormatted capacities Factory-installed optionsProgrammable drive capacity Access time Performance characteristicsInternal drive characteristics Seek performanceGeneral performance characteristics Format command execution time minutesStart/stop time Cache operation Prefetch/multi-segmented cache controlCaching write data Prefetch operation Recoverable Errors Reliability specificationsError rates Unrecoverable ErrorsPreventive maintenance Reliability and serviceInterface errors Hot plugging the drivePerformance impact 4 S.M.A.R.TControlling S.M.A.R.T Reporting controlThermal monitor Temperature Log Page 0Dh Parameter Code DescriptionPredictive failures Drive Self Test DSTDST failure definition ImplementationShort test Function Code 001b Product warrantyExtended test Function Code 010b Shipping DC power requirements Physical/electrical specificationsAC power requirements ST3600002SS DC power requirementsST3450802SS DC power requirements General DC power requirement notesConducted noise immunity Power sequencingCurrent profiles Typical ST3600002SS drive +5V and +12V current profiles ST3600002SS Power dissipationST3450802SS Temperature a. Operating Environmental limitsShock and vibration Relative humidityEffective altitude sea level a. Operating ShockPackage size Packaged/product weight Drop height Recommended mountingAcoustics Air cleanlinessVibration a. Operating-normal Corrosive environmentChina Restriction of Hazardous Substances RoHS Directive Mechanical specifications Physical dimensionsDrive internal defects/errors Defect and error managementDrive error recovery procedures 77.81 Media Pre-Scan SAS system errorsBackground Media Scan Deferred Auto-ReallocationIdle Read After Write Installation Drive orientationCooling Air flowDrive mounting GroundingSAS features Interface requirementsDual port support Scsi commands supported Commands supported by Cheetah NS 10K.2 SAS family drivesCommands supported by Cheetah NS 10K.2 SAS family drives Commands supported by Cheetah NS 10K.2 SAS family drives Commands supported by Cheetah NS 10K.2 SAS family drives 2Mode Sense data Inquiry dataBytes Data hex Page 2.1 ST3600002SS Mode Sense data Mode Pages2.2 ST3450802SS Mode Sense data Supported Feature or condition Miscellaneous operating features and conditionsMiscellaneous features Miscellaneous statusSAS physical interface Datum B Physical characteristics Connector requirementsPin descriptions Pin Signal name Signal typeElectrical description SAS pin descriptionsSAS transmitters and receivers Signal characteristicsPower Ready LED OutGeneral interface characteristics LED drive signalDifferential signals Eye masks Eye masks overviewReceive eye mask X2OP 0, 5xadditional sinusoidal jitter X1OP Transmitter signal characteristics Signal characteristica Units 5Gb/s 0Gb/sMaximum allowable jitter Receiver signal characteristicsSignal characteristic Units 5Gb/s 0Gb/s 5Gb/s m, n 0Gb/s m, n Deterministic jitterq5Gb/sa 0Gb/sa Sinusoidal Deterministic Total Receiver jitter toleranceImpedance requirements Sheet 1 JitterhImpedance requirements Sheet 2 Electrical TxRx connections= -5, 437dB Shows the zero-length test load Receiver characteristics SAS-2 Specification complianceAdditional information Presales Support Seagate Technology support servicesTechnical Support Data Recovery Services Authorized Service Centers Warranty ServiceData Recovery Services Call Center Toll-free Direct dial Index Page SAS See also cooling Page Seagate Technology LLC
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