Seagate ST3146356SS, ST3300656SS 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.

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

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Contents ST3450856SS ST3300656SS ST3146356SS Cheetah 15K.6 SASPage Contents Installation Defect and error managementSeagate Technology support services Interface requirementsCheetah 15K.6 SAS disk drive List of FiguresCheetah 15K.6 SAS Product Manual, Rev. a Cheetah 15K.6 SAS disk drive ScopeCheetah 15K.6 SAS Product Manual, Rev. a Standards Standards, compliance and reference documentsElectromagnetic compatibility Electromagnetic susceptibilityEuropean Union Restriction of Hazardous Substances RoHS ComplianceReference documents Cheetah 15K.6 SAS Product Manual, Rev. a General description Standard features Media descriptionPerformance Options factory installed Factory-installed accessoriesReliability Formatted capacitiesCheetah 15K.6 SAS Product Manual, Rev. a Internal 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 monitorPrimary Temperature Temperature Log Page 0DhReference Temperature Parameter Code DescriptionInvoking DST State of the drive prior to testingShort and extended tests Short test Function Code 001bAbort Product warrantyShipping Product repair and return informationCheetah 15K.6 SAS Product Manual, Rev. a AC power requirements Physical/electrical specificationsDC power requirements ST3450856SS DC power requirementsST3146356SS DC power requirements ST3300656SS DC power requirementsST3300656SS Gbit mode Amps ST3146356SS Gbit mode AmpsPower sequencing General DC power requirement notesConducted noise immunity Current profilesTypical ST3450856SS current profiles Typical ST3300656SS current profiles Typical ST3146356SS current profiles ST3450856SS in 3 Gbit operation Power dissipationST3300656SS in 3 Gbit operation ST3300656SS CURRENT/POWER vs Throughput SAS 3.0GBST3146356SS CURRENT/POWER vs Throughput SAS 3.0GB ST3146356SS in 3 Gbit operationRandom 8 Block Reads Environmental limits TemperatureEffective altitude sea level Relative humidityShock and vibration ShockRecommended mounting Package size Packaged/product weight Drop heightVibration Air cleanlinessAcoustics Corrosive environmentMechanical specifications Physical dimensions Cheetah 15K.6 SAS Product Manual, Rev. a Defect and error management Drive internal defects/errorsDrive error recovery procedures 51.87 SAS system errors Background Media ScanMedia Pre-Scan Idle Read After Write Deferred Auto-ReallocationDrive orientation InstallationAir flow CoolingGrounding Drive mountingCheetah 15K.6 SAS Product Manual, Rev. a Interface requirements SAS featuresDual port support Scsi commands supported Commands supported by Cheetah 15K.6 SAS family drivesCommand name Command code Supported 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 Mode Sense data Inquiry dataBytes Data hex Page Mode Pages 2.1 ST3450856SS Mode Sense data2.2 ST3300656SS Mode Sense data 2.3 ST3146356SS Mode Sense data Miscellaneous features Miscellaneous operating features and conditionsSupported Feature or condition Miscellaneous statusSAS physical interface Datum B Connector requirements Physical characteristicsElectrical description Pin Signal name Signal typePin descriptions SAS pin descriptionsPower Signal characteristicsSAS transmitters and receivers Ready LED OutDifferential signals LED drive signalGeneral interface characteristics Eye masks Eye masks overviewJitter tolerance masks Receive eye maskAbsolute amplitude Normalized time in UISinusoidal Peak-toJitter Frequency in kHzSignal characteristica Units Gbps Transmitter signal characteristicsSignal characteristic Units Gbps Receiver signal characteristicsMaximum allowable jitter Gbps m, n Deterministic jitterqReceiver jitter tolerance Impedance specificationsCompliant jitter test pattern Cjtpat Impedance requirements Sheet 1Transmitter characteristics Impedance requirements Sheet 2Electrical TxRx connections = -5,437dB Shows the zero-length test load Receiver characteristics Cheetah 15K.6 SAS Product Manual, Rev. a Internet Seagate Technology support servicesPresales Support Technical SupportWarranty Service Data Recovery Services Authorized Service CentersData Recovery Services Call Center Toll-free Direct dial Numerics IndexPage SAS See also cooling
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