Seagate ST3146756SS (FDE) 4 S.M.A.R.T, Controlling S.M.A.R.T, Performance impact, Milliseconds

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5.2.4S.M.A.R.T.

S.M.A.R.T. is an acronym for Self-Monitoring Analysis and Reporting Technology. This technology is intended to recognize conditions that indicate imminent drive failure and is designed to provide sufficient warning of a failure to allow you to back up the data before an actual failure occurs.

Note. The drive’s firmware monitors specific attributes for degradation over time but can’t predict instanta- neous drive failures.

Each monitored attribute has been selected to monitor a specific set of failure conditions in the operating per- formance of the drive and the thresholds are optimized to minimize “false” and “failed” predictions.

Controlling S.M.A.R.T.

The operating mode of S.M.A.R.T. is controlled by the DEXCPT and PERF bits on the Informational Exceptions Control mode page (1Ch). Use the DEXCPT bit to enable or disable the S.M.A.R.T. feature. Setting the DEX- CPT bit disables all S.M.A.R.T. functions. When enabled, S.M.A.R.T. collects on-line data as the drive performs normal read and write operations. When the PERF bit is set, the drive is considered to be in “On-line Mode Only” and will not perform off-line functions.

You can measure off-line attributes and force the drive to save the data by using the Rezero Unit command. Forcing S.M.A.R.T. resets the timer so that the next scheduled interrupt is in two hours.

You can interrogate the drive through the host to determine the time remaining before the next scheduled mea- surement and data logging process occurs. To accomplish this, issue a Log Sense command to log page 0x3E. This allows you to control when S.M.A.R.T. interruptions occur. Forcing S.M.A.R.T. with the RTZ command resets the timer.

Performance impact

S.M.A.R.T. attribute data is saved to the disk so that the events that caused a predictive failure can be recre- ated. The drive measures and saves parameters once every two hours subject to an idle period on the drive interfaces. The process of measuring off-line attribute data and saving data to the disk is uninterruptable. The maximum on-line only processing delay is summarized below:

Maximum processing delay

 

 

On-line only delay

Fully-enabled delay

 

DEXCPT = 0, PERF = 1

DEXCPT = 0, PERF = 0

S.M.A.R.T. delay times

42 milliseconds

163 milliseconds

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

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Contents ST3450856SS ST3300656SSST3146356SS Page Contents Installation Defect and error managementSeagate Technology support services Interface requirementsModel Number Full Disk Encryption FDE ScopeCheetah 15K.6 SAS Product Manual, Rev. B Standards Standards, compliance and reference documentsElectromagnetic compatibility Electromagnetic susceptibilityEuropean Union Restriction of Hazardous Substances RoHS ComplianceReference documents Cheetah 15K.6 SAS Product Manual, Rev. B General description Standard features Media descriptionPerformance Reliability Factory-installed optionsFormatted capacities Programmable drive capacityCheetah 15K.6 SAS Product Manual, Rev. B Internal drive characteristics Performance characteristicsAccess time Seek timeGeneral performance characteristics Format command execution time minutesStart/stop time 176 144 100Cache 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 monitorState of the drive prior to testing Temperature Log Page 0Dh Parameter Code DescriptionDrive Self Test DST DST failure definitionShort and extended tests Invoking DSTShort test Function Code 001b Extended test Function Code 010bAbort Product warrantyShipping Product repair and return informationCheetah 15K.6 SAS Product Manual, Rev. B AC power requirements Physical/electrical specificationsDC power requirements ST3450856SS DC power requirementsST3300656SS DC power requirements ST3450056SS FDE DC power requirementsST3450056SS FDE Gbit mode Amps ST3300656SS Gbit mode AmpsST3146356SS DC power requirements ST3300056SS FDE DC power requirementsST3300056SS FDE Gbit mode Amps ST3146356SS Gbit mode AmpsST3146756SS FDE Gbit mode Amps ST3146756SS FDE DC power requirementsPower sequencing Conducted noise immunityCurrent profiles 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 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. B 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-ReallocationInstallation Drive orientationCooling Air flow Grounding Drive mountingCheetah 15K.6 SAS Product Manual, Rev. B 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 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 Miscellaneous features Miscellaneous operating features and conditionsMiscellaneous status SAS physical interfacePhysical 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 characteristicsReceiver signal characteristics Signal characteristic Units GbpsMaximum allowable jitter Receiver 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. B Internet Seagate Technology support servicesPresales Support Technical SupportWarranty Service Data Recovery Services Authorized Service CentersData Recovery Services Call Center Toll-free Direct dial Numerics IndexIraw SAS See also cooling
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