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

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8.0Defect 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 8.4)

•Media Pre-Scan (see Section 8.5)

•Deferred Auto-Reallocation (see Section 8.6)

•Idle Read After Write (see Section 8.7)

The read error rates and specified storage capacities are not dependent on host (initiator) defect management routines.

8.1Drive 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.

8.2Drive 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-

Cheetah NS 10K.2 SAS Product Manual, Rev. F

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Contents ST3600002SS ST3450802SS Cheetah NS 10K.2 SASPage Contents Interface requirements Defect and error managementInstallation Seagate Online Support and Services Seagate Technology support servicesScope Electromagnetic susceptibility Standards, compliance and reference documentsStandards Electromagnetic compatibilityCompliance Reference documents General description Reliability Standard featuresMedia description PerformanceProgrammable drive capacity Factory-installed optionsFormatted capacities Seek performance Performance characteristicsInternal drive characteristics Access timeStart/stop time Format command execution time minutesGeneral performance characteristics Caching write data Prefetch/multi-segmented cache controlCache operation Prefetch operation Unrecoverable Errors Reliability specificationsError rates Recoverable ErrorsHot plugging the drive Reliability and serviceInterface errors Preventive maintenanceReporting control 4 S.M.A.R.TControlling S.M.A.R.T Performance impactDrive Self Test DST Temperature Log Page 0Dh Parameter Code DescriptionPredictive failures Thermal monitorImplementation DST failure definitionExtended test Function Code 010b Product warrantyShort test Function Code 001b Shipping ST3600002SS DC power requirements Physical/electrical specificationsAC power requirements DC power requirementsGeneral DC power requirement notes ST3450802SS DC power requirementsCurrent profiles Power sequencingConducted noise immunity Typical ST3600002SS drive +5V and +12V current profiles ST3450802SS Power dissipationST3600002SS Environmental limits Temperature a. OperatingShock Relative humidityEffective altitude sea level a. Operating Shock and vibrationRecommended mounting Corrosive environment Air cleanliness Vibration a. Operating-normal AcousticsChina Restriction of Hazardous Substances RoHS Directive Physical dimensions Mechanical specificationsDrive error recovery procedures Defect and error managementDrive internal defects/errors 77.81 Deferred Auto-Reallocation SAS system errorsBackground Media Scan Media Pre-ScanIdle Read After Write Drive orientation InstallationAir flow CoolingGrounding Drive mountingInterface requirements SAS featuresDual port support Commands supported by Cheetah NS 10K.2 SAS family drives Scsi commands supportedCommands 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 10.3.2Mode Sense data Inquiry dataPage Mode Pages 10.3.2.1 ST3600002SS Mode Sense data10.3.2.2 ST3450802SS Mode Sense data Miscellaneous status Miscellaneous operating features and conditionsMiscellaneous features SAS physical interface Datum B Connector requirements Physical characteristicsSAS pin descriptions Electrical descriptionPin descriptions Ready LED Out Signal characteristicsPower SAS transmitters and receivers10.5.2.1 Eye masks 10.5.2.1.1 Eye masks overview LED drive signalDifferential signals General interface characteristicsReceive eye mask 2OP 0, 5 xadditional sinusoidal jitter X 1OP Transmitter signal characteristics Maximum allowable jitter Receiver signal characteristicsImpedance requirements Sheet 1 Compliant jitter test pattern CjtpatElectrical TxRx connections Impedance requirements Sheet 2= -5, 437dB Shows the zero-length test load Additional information SAS-2 Specification complianceReceiver characteristics Cheetah NS 10K.2 SAS Product Manual, Rev. F Index Page SAS See also cooling Page Americas Seagate Technology LLC
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