Seagate ST3300555SS, ST3146755SS 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.

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Contents Cheetah T10 SAS Page Contents Interface requirements Defect and error managementInstallation Seagate Technology support servicesList of Figures Cheetah T10 SAS Product Manual, Rev. a Cheetah T10 SAS disc drive ScopeCheetah T10 SAS Product Manual, Rev. a Electromagnetic susceptibility Standards, compliance and reference documentsStandards Electromagnetic compatibilityCompliance Reference documents Cheetah T10 SAS Product Manual, Rev. a General description Media description Standard featuresPerformance Programmable drive capacity Factory-installed accessoriesReliability Formatted capacitiesUser-installed accessories Options factory installedSeek time Performance characteristicsInternal drive characteristics Access timeGeneral performance characteristics Format command execution time minutesStart/stop time Cache operation Prefetch/multi-segmented cache controlPrefetch operation Caching write dataUnrecoverable Errors Reliability specificationsError rates Recoverable ErrorsPreventive maintenance Reliability and serviceSeek errors Interface errorsPerformance impact Hot plugging the drive4 S.M.A.R.T Controlling S.M.A.R.TThermal monitor Reporting controlDetermining rate Predictive failuresParameter Code Description Temperature Log Page 0DhPrimary Temperature Reference TemperatureShort test Function Code 001b State of the drive prior to testingInvoking DST Short and extended testsProduct repair and return information Product warrantyAbort ShippingCheetah T10 SAS Product Manual, Rev. a ST3300555SS DC power requirements Physical/electrical specificationsAC power requirements DC power requirementsST373355SS Gbit mode Amps ST3146755SS DC power requirementsST373355SS DC power requirements ST3146755SS Gbit mode AmpsCurrent profiles General DC power requirement notesPower sequencing Conducted noise immunityTypical ST3300555SS drive current profiles Typical ST3146755SS drive current profiles Typical ST373355SS drive current profiles ST3300555SS in 3 Gbit operation Power dissipationST3300555SS in 1.5 Gbit operation ST3146755SS in 1.5 Gbit operation ST3146755SS in 3 Gbit operationST373355SS in 1.5 Gbit operation ST373355SS in 3 Gbit operationEnvironmental limits Temperature a. OperatingShock Relative humidityEffective altitude sea level a. Operating Shock and vibration Recommended mounting Package size Packaged/product weight Drop heightVibration a. Operating-normal Air cleanlinessCorrosive environment Acoustics Mechanical specificationsDrive internal defects/errors Defect and error managementDrive error recovery procedures Write retry count LBA cumulative, msec Background Media Scan SAS system errorsMedia Pre-Scan Idle Read After Write Deferred Auto-ReallocationDrive orientation InstallationAir flow CoolingGrounding Drive mountingCheetah T10 SAS Product Manual, Rev. a Interface requirements SAS featuresDual port support Commands supported by Cheetah T10 SAS family drives Scsi commands supportedCommand name Command code Supported Commands supported by Cheetah T10 SAS family drives Commands supported by Cheetah T10 SAS family drives Commands supported by Cheetah T10 SAS family drives Bytes Data hex Mode Sense dataInquiry data Cheetah T10 SAS inquiry dataPage Mode Pages ST3300555SS Mode Sense dataST3146755SS Mode Sense data ST373355SS Mode Sense data Miscellaneous status Miscellaneous operating features and conditionsMiscellaneous features Supported Feature or conditionSAS physical interface Datum B Connector requirements Physical characteristicsSAS pin descriptions Pin Signal name Signal typeElectrical description Pin descriptionsReady LED Out Signal characteristicsPower SAS transmitters and receiversEye masks Eye masks overview LED drive signalDifferential signals General interface characteristicsNormalized time in UI Receive eye maskJitter tolerance masks Absolute amplitudeFrequency in kHz Peak-toSinusoidal JitterSignal characteristica Units Gbps Transmitter signal characteristicsGbps m, n Deterministic jitterq Receiver signal characteristicsSignal characteristic Units Gbps Maximum allowable jitterImpedance requirements Sheet 1 Impedance specificationsReceiver jitter tolerance Compliant jitter test pattern CjtpatImpedance requirements Sheet 2 Transmitter characteristicsElectrical TxRx connections = -5,437dB Shows the zero-length test load Receiver characteristics Cheetah T10 SAS Product Manual, Rev. a Presales Support Seagate Technology support servicesWarranty Service Internet MySeagate Spp.seagate.comData Recovery Services Data Recovery Services Authorized Service CentersCall center Presales and Technical Support Warranty Service FAX services-All Europe toll callToll-free support numbers Africa/Middle East support services Numerics IndexPage SAS See also cooling Page Seagate Technology LLC
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