Seagate ST3400755SS manual Predictive failures, Thermal monitor, Temperature Log Page 0Dh

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Error rate is the number of errors per operation. The algorithm that S.M.A.R.T. uses to record rates of error is to set thresholds for the number of errors and their interval. If the number of errors exceeds the threshold before the interval expires, the error rate is considered to be unacceptable. If the number of errors does not exceed the threshold before the interval expires, the error rate is considered to be acceptable. In either case, the inter- val and failure counters are reset and the process starts over.

Predictive failures

S.M.A.R.T. signals predictive failures when the drive is performing unacceptably for a period of time. The firm- ware keeps a running count of the number of times the error rate for each attribute is unacceptable. To accom- plish this, a counter is incremented each time the error rate is unacceptable and decremented (not to exceed zero) whenever the error rate is acceptable. If the counter continually increments such that it reaches the pre- dictive threshold, a predictive failure is signaled. This counter is referred to as the Failure History Counter. There is a separate Failure History Counter for each attribute.

5.2.6Thermal monitor

Cheetah drives implement a temperature warning system which:

1.Signals the host if the temperature exceeds a value which would threaten the drive.

2.Signals the host if the temperature exceeds a user-specified value.

3.Saves a S.M.A.R.T. data frame on the drive which exceeds the threatening temperature value.

A temperature sensor monitors the drive temperature and issues a warning over the interface when the tem- perature exceeds a set threshold. The temperature is measured at power-up and then at ten-minute intervals after power-up.

The thermal monitor system generates a warning code of 01-0B01 when the temperature exceeds the speci- fied limit in compliance with the SCSI standard. The drive temperature is reported in the FRU code field of mode sense data. You can use this information to determine if the warning is due to the temperature exceeding the drive threatening temperature or the user-specified temperature.

This feature is controlled by the Enable Warning (EWasc) bit, and the reporting mechanism is controlled by the Method of Reporting Informational Exceptions field (MRIE) on the Informational Exceptions Control (IEC) mode page (1Ch).

The current algorithm implements two temperature trip points. The first trip point is set at 68°C which is the maximum temperature limit according to the drive specification. The second trip point is user-selectable using the Log Select command. The reference temperature parameter in the temperature log page (see Table 1) can be used to set this trip point. The default value for this drive is 68°C, however, you can set it to any value in the range of 0 to 68°C. If you specify a temperature greater than 68°C in this field, the temperature is rounded down to 68°C. A sense code is sent to the host to indicate the rounding of the parameter field.

Table 1:

Temperature Log Page (0Dh)

 

 

Parameter Code

Description

 

 

 

0000h

 

Primary Temperature

 

 

 

0001h

 

Reference Temperature

 

 

 

5.2.7Drive Self Test (DST)

Drive Self Test (DST) is a technology designed to recognize drive fault conditions that qualify the drive as a failed unit. DST validates the functionality of the drive at a system level.

There are two test coverage options implemented in DST:

1.Extended test

2.Short text

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Cheetah NS SAS Product Manual, Rev. B

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Contents Cheetah NS SAS ST3400755SSPage Contents Defect and error management InstallationSeagate Technology support services Interface requirementsList of Figures Typical ST3400755SS drive +5V and +12V current profilesCheetah NS SAS Product Manual, Rev. B Scope Cheetah NS SAS Product Manual, Rev. B Standards, compliance and reference documents StandardsElectromagnetic compatibility Electromagnetic susceptibilityCompliance Reference documents Cheetah NS SAS Product Manual, Rev. B General description Standard features Media descriptionPerformance ReliabilityFactory-installed options Formatted capacitiesProgrammable drive capacity ST3400755SSCheetah NS SAS Product Manual, Rev. B Performance characteristics Internal drive characteristicsAccess time Seek performanceFormat command execution time minutes General performance characteristicsStart/stop time Prefetch/multi-segmented cache control Cache operationCaching write data Prefetch operation Reliability 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 controlTemperature Log Page 0Dh Predictive failuresThermal monitor State of the drive prior to testing DST failure definitionImplementation Invoking DSTProduct warranty Short test Function Code 001bExtended test Function Code 010b Log page entriesShipping Product repair and return informationCheetah NS SAS Product Manual, Rev. B Physical/electrical specifications AC power requirementsDC power requirements ST3400755SS DC power requirementsGeneral DC power requirement notes Power sequencingConducted noise immunity Current profilesPower dissipation Typical ST3400755SS drive +5V and +12V current profilesTemperature Environmental limitsRelative humidity Effective altitude sea levelShock and vibration ShockPackage size Packaged/product weight Drop height Recommended mountingAir cleanliness VibrationAcoustics Corrosive environmentX表示该部件（于同类物品程度上）所含的危险和有毒物质中国RoHS MCV标准所定义的门槛值。 China Restriction of Hazardous Substances RoHS DirectiveMechanical specifications Physical dimensionsCheetah NS SAS Product Manual, Rev. B Defect and error management Drive internal defects/errorsDrive error recovery procedures 77.87 SAS system errors Background Media ScanMedia Pre-Scan Deferred Auto-Reallocation Idle Read After WriteInstallation Drive orientationCooling Air flowDrive mounting GroundingCheetah NS SAS Product Manual, Rev. B SAS features Interface requirementsDual port support Scsi commands supported Commands supported by Cheetah NS SAS family drivesCommand name Command code Supported Commands supported by Cheetah NS SAS family drives Commands supported by Cheetah NS SAS family drives Commands supported by Cheetah NS SAS family drives Mode Sense data Inquiry dataCheetah NS SAS inquiry data Bytes Data hex Page 2.1 ST3400755SS Mode Sense data Mode PagesMiscellaneous operating features and conditions Miscellaneous featuresSupported Feature or condition Miscellaneous statusSAS physical interface Datum B Physical characteristics Connector requirementsPin Signal name Signal type Electrical descriptionPin descriptions SAS pin descriptionsSignal characteristics PowerSAS transmitters and receivers Ready LED OutLED drive signal Differential signalsGeneral interface characteristics Eye masks Eye masks overviewReceive eye mask Jitter tolerance masksAbsolute amplitude Normalized time in UIPeak-to SinusoidalJitter Frequency in kHzTransmitter signal characteristics Signal characteristica Units GbpsReceiver signal characteristics Signal characteristic Units GbpsMaximum allowable jitter Gbps m, n Deterministic jitterqImpedance specifications Receiver jitter toleranceCompliant 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 NS SAS Product Manual, Rev. B Seagate Technology support services InternetPresales Support Technical SupportWarranty Service Data Recovery Services Authorized Service CentersData Recovery Services Call Center Toll-free Direct dial Index NumericsPage SAS See also cooling
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