Seagate 100620418, ST9500621SS manual Defect and error management, Drive internal defects/errors

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10.0Defect 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 10.4)

•Media Pre-Scan (see Section 10.5)

•Deferred Auto-Reallocation (see Section 10.6)

•Idle Read After Write (see Section 10.7)

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

10.1Drive 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.

10.2Drive 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 SCSI 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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Constellation.2 SAS Product Manual, Rev. H

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Contents ST91000640SSST91000641SS ST9500620SSST9500621SS ST91000642SS ST9500622SSStandard Models Self-Encrypting Drive Models SED Fips 140-2 ModelsRevision history Contents Defect and error management InstallationAbout Fips About self-encrypting drives Interface requirementsPage Constellation.2 SAS Product Manual, Rev. H List of Figures Constellation.2 SAS Product Manual, Rev. H Seagate Technology support services Seagate Online Support and ServicesScope Applicable standards and reference documentation StandardsElectromagnetic compatibility Electromagnetic susceptibilityElectromagnetic compliance Electromagnetic compliance for the European UnionAustralian C-Tick Korean KCCEuropean Union Restriction of Hazardous Substances RoHS China Restriction of Hazardous Substances RoHS DirectiveReference documents Self-Encrypting Drives Reference ManualGeneral description Standard features Media descriptionPerformance ReliabilityFormatted capacities Programmable drive capacityFactory-installed options Performance characteristics Internal drive characteristicsSeek performance characteristics Access timeGeneral performance characteristics Start/stop timePrefetch/multi-segmented cache control Cache operationCaching write data Prefetch operationReliability specifications Error ratesRecoverable Errors Unrecoverable ErrorsReliability and service Seek errorsInterface errors Preventive maintenance4 S.M.A.R.T Controlling S.M.A.R.TPerformance impact Reporting controlPredictive failures Temperature Log Page 0Dh Parameter Code DescriptionThermal monitor State of the drive prior to testing Drive Self Test DSTDST failure definition ImplementationShort and extended tests Short test Function Code 001bExtended test Function Code 010b Log page entriesProduct warranty ShippingStorage Product repair and return informationPowerChoiceTM power management Physical/electrical specificationsPowerChoice modes AC power requirements DC power requirements1000GB drive Standard & SED model DC power requirements 500GB drive Standard & SED model DC power requirements Power sequencing General DC power requirement notesConducted noise immunity Current profiles TB model current profilesGB model current profiles Power dissipation 1TB model drive in 3Gb operation1TB model drive in 6Gb operation 500GB model drive in 3Gb operation 500GB model drive in 6Gb operation Environmental limits Temperature a. OperatingRelative humidity Shock and vibration Effective altitude sea level a. OperatingShock Recommended mounting Air cleanliness Vibration a. Operating-normalAcoustics Corrosive environmentSee Section Constellation.2 SAS Product Manual, Rev. H Mechanical specifications Mounting configuration dimensionsAbout Fips PurposeValidation Program Seagate Enterprise SEDExample of Fips tamper evidence labels Controlled access Admin SPAbout self-encrypting drives Data encryptionAuthenticated firmware download Random number generator RNGDrive locking Data bandsPower requirements Supported commandsDrive internal defects/errors Defect and error managementDrive error recovery procedures SAS system errors Media Pre-Scan Background Media ScanDeferred Auto-Reallocation Setting and determining the current Type Level Idle Read After WriteProtection Information PI Levels of PIIdentifying a Protection Information drive Installation Drive orientationCooling Air flowDrive mounting GroundingSAS features Interface requirementsDual port support Scsi commands supported Supported commandsSupported commands Supported commands Supported commands Inquiry data Mode Sense dataConstellation.2 inquiry data Page Block Descriptor 00 00 00 00 3a 38 60 30 00 00 00 00 00 00 02 Miscellaneous features Miscellaneous operating features and conditionsMiscellaneous status SAS physical interface Datum B Section C C Section a a Physical characteristics Connector requirementsElectrical description Pin descriptionsSignal characteristics PowerSAS transmitters and receivers Ready LED OutSAS-2 Specification Compliance LED drive signalDifferential signals General interface characteristicsIndex NumericsKCC Msid Mtbf See also cooling Page Constellation.2 SAS Product Manual, Rev. H Page Seagate Technology LLC Americas
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