Seagate ST3146356SSIM, ST3146854LC 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.

Cheetah 15K.6 SAS Product Manual, Rev. B

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Contents ST3146356SS ST3450856SSST3300656SS Page Contents Interface requirements Defect and error managementInstallation Seagate Technology support servicesModel Number Full Disk Encryption FDE ScopeCheetah 15K.6 SAS Product Manual, Rev. B Electromagnetic susceptibility Standards, compliance and reference documentsStandards Electromagnetic compatibilityEuropean Union Restriction of Hazardous Substances RoHS ComplianceReference documents Cheetah 15K.6 SAS Product Manual, Rev. B General description Performance Standard featuresMedia description Programmable drive capacity Factory-installed optionsReliability Formatted capacitiesCheetah 15K.6 SAS Product Manual, Rev. B Seek time Performance characteristicsInternal drive characteristics Access time176 144 100 Format command execution time minutesGeneral performance characteristics Start/stop timeCache operation Prefetch/multi-segmented cache controlPrefetch operation Caching write dataUnrecoverable Errors Reliability specificationsError rates Recoverable ErrorsPreventive maintenance Reliability and serviceSeek errors Interface errorsMilliseconds 4 S.M.A.R.TControlling S.M.A.R.T Performance impactThermal monitor Reporting controlDetermining rate Predictive failuresDST failure definition Temperature Log Page 0Dh Parameter Code DescriptionState of the drive prior to testing Drive Self Test DSTExtended test Function Code 010b Invoking DSTShort and extended tests Short test Function Code 001bProduct repair and return information Product warrantyAbort ShippingCheetah 15K.6 SAS Product Manual, Rev. B ST3450856SS DC power requirements Physical/electrical specificationsAC power requirements DC power requirementsST3300656SS Gbit mode Amps ST3450056SS FDE DC power requirementsST3300656SS DC power requirements ST3450056SS FDE Gbit mode AmpsST3146356SS Gbit mode Amps ST3300056SS FDE DC power requirementsST3146356SS DC power requirements ST3300056SS FDE Gbit mode AmpsST3146756SS FDE Gbit mode Amps ST3146756SS FDE DC power requirementsCurrent profiles Power sequencingConducted noise immunity Typical 450GB current profiles Typical 146GB current profiles ST3450856SS model Power dissipationST3450056SS FDE model ST3300656SS model ST3300056SS FDE model ST3146356SS model ST3146756SS FDE model in 3 Gbit operation Environmental limits TemperatureShock Relative humidityEffective altitude sea level Shock and vibrationRecommended mounting Package size Packaged/product weight Drop heightCorrosive environment Air cleanlinessVibration Acoustics Mechanical specifications Physical dimensions Cheetah 15K.6 SAS Product Manual, Rev. B Drive error recovery procedures Defect and error managementDrive internal defects/errors 51.87 Media Pre-Scan SAS system errorsBackground Media Scan Idle Read After Write Deferred Auto-ReallocationCooling InstallationDrive orientation Air flow Grounding Drive mountingCheetah 15K.6 SAS Product Manual, Rev. B Interface requirements SAS featuresDual port support Command name Command code Supported Scsi commands supportedCommands 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 Commands supported by Cheetah 15K.6 SAS family drives Bytes Data hex Inquiry dataMode Sense data Mode Pages 2.1 ST3450856SS/ST3450056SS Mode Sense data2.2 ST3300656SS/ST3300056SS Mode Sense data 2.3 ST3146356SS/ST3146756SS Mode Sense data SAS physical interface Miscellaneous operating features and conditionsMiscellaneous features Miscellaneous statusPhysical 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 characteristicsMaximum allowable jitter Receiver signal characteristicsSignal characteristic Units Gbps Impedance requirements Sheet 1 Impedance specificationsReceiver jitter tolerance Compliant jitter test pattern CjtpatElectrical TxRx connections Transmitter characteristicsImpedance requirements Sheet 2 = -5,437dB Shows the zero-length test load Receiver characteristics Cheetah 15K.6 SAS Product Manual, Rev. B Technical Support Seagate Technology support servicesInternet Presales SupportData Recovery Services Call Center Toll-free Direct dial Warranty ServiceData Recovery Services Authorized Service Centers Numerics IndexIraw SAS See also cooling
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