Idle Read After Write | Seagate ST9500431SS, ST9500430SS manual

10.7Idle Read After Write

Idle Read After Write (IRAW) utilizes idle time to verify the integrity of recently written data. During idle periods, no active system requests, the drive reads recently written data from the media and compares it to valid write command data resident in the drives data buffer. Any sectors that fail the comparison result in the invocation of a rewrite and auto-reallocation process. The process attempts to rewrite the data to the original location. If a verification of this rewrite fails, the sector is re-mapped to a spare location.

42	Constellation SAS Product Manual, Rev. E

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Seagate ST9500431SS, ST9500430SS, ST9500432SS manual Idle Read After Write

Contents

Standard Model Self-Encrypting Drive Model ST9500430SSST9500431SSST9500432SS SED Fips 140-2 Model Revision history Contents About Fips About self-encrypting drives Defect and error managementInstallation Interface requirements Power Constellation SAS Product Manual, Rev. E List of Figures GB model current profiles Constellation SAS Product Manual, Rev. E Seagate Technology support services Seagate Online Support and Services Scope Electromagnetic compatibility Applicable standards and reference documentationStandards Electromagnetic susceptibility Australian C-Tick Electromagnetic complianceElectromagnetic compliance for the European Union Korean KCC Reference documents European Union Restriction of Hazardous Substances RoHS General description Standard features Media description Formatted capacities PerformanceReliability Programmable drive capacity Factory-installed options Seek performance characteristics Performance characteristicsInternal drive characteristics Access time General performance characteristics Start/stop time Prefetch/multi-segmented cache control Cache operation Caching write data Prefetch operation Recoverable Errors Reliability specificationsError rates Unrecoverable Errors Interface errors Reliability and serviceSeek errors Preventive maintenance Performance impact 4 S.M.A.R.TControlling S.M.A.R.T Reporting control Thermal monitor Temperature Log Page 0Dh Parameter Code DescriptionPredictive failures DST failure definition State of the drive prior to testingDrive Self Test DST Implementation Extended test Function Code 010b Short and extended testsShort test Function Code 001b Log page entries Product repair and return information Product warrantyShipping PowerChoice modes Physical/electrical specificationsPowerChoiceTM power management AC power requirements DC power requirementsPage Conducted noise immunity General DC power requirement notesPower sequencing Current profiles GB model current profiles Power dissipation ST9500430SS, ST9500431SS and ST9500432SS in 3 Gbit operation ST9500430SS, ST9500431SS and ST9500432SS in 6 Gbit operation Temperature a. Operating Environmental limits Shock and vibration Relative humidityEffective altitude sea level a. Operating ShockPage Recommended mounting Corrosive environment Air cleanlinessVibration a. Operating-normal Acoustics Mechanical specifications Mounting configuration dimensions Level 2 security About FipsPurpose About self-encrypting drives Controlled accessAdmin SP Data encryption Drive locking Default passwordRandom number generator RNG Data bands Supported commands Authenticated firmware downloadPower requirements Cryptographic erase Drive error recovery procedures Defect and error managementDrive internal defects/errors SAS system errors Deferred Auto-Reallocation Background Media ScanMedia Pre-Scan Idle Read After Write Installation Drive orientation Cooling Air flow Drive mounting Grounding SAS features Interface requirements Dual port support Scsi commands supported Supported commands Supported commands Supported commands Supported commands Constellation inquiry data Mode Sense dataInquiry data Page Mode Data Header Miscellaneous status Miscellaneous operating features and conditionsMiscellaneous features SAS physical interface Datum B Section C C Section a a Electrical description Physical characteristicsConnector requirements Pin descriptions SAS transmitters and receivers Signal characteristicsPower Ready LED Out Differential signals SAS-2 Specification ComplianceLED drive signal General interface characteristics Constellation SAS Product Manual, Rev. E Index Numerics KCC Msid Mtbf See also cooling Page Constellation SAS Product Manual, Rev. E Page Seagate Technology LLC