Seagate ST3146356SSIM Reporting control, Determining rate, Predictive failures, Thermal monitor

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Reporting control

Reporting is controlled by the MRIE bits in the Informational Exceptions Control mode page (1Ch). Subject to the reporting method, the firmware will issue to the host an 01-5Dxx sense code. The error code is preserved through bus resets and power cycles.

Determining rate

S.M.A.R.T. monitors the rate at which errors occur and signals a predictive failure if the rate of degraded errors increases to an unacceptable level. To determine rate, error events are logged and compared to the number of total operations for a given attribute. The interval defines the number of operations over which to measure the rate. The counter that keeps track of the current number of operations is referred to as the Interval Counter.

S.M.A.R.T. measures error rates. All errors for each monitored attribute are recorded. A counter keeps track of the number of errors for the current interval. This counter is referred to as the Failure Counter.

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.

5.2.5Thermal monitor

Cheetah 15K.6 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 11)

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

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Contents ST3300656SS ST3450856SSST3146356SS Page Contents Seagate Technology support services Defect and error managementInstallation Interface requirementsScope Model Number Full Disk Encryption FDECheetah 15K.6 SAS Product Manual, Rev. B Electromagnetic compatibility Standards, compliance and reference documentsStandards Electromagnetic susceptibilityCompliance European Union Restriction of Hazardous Substances RoHSReference documents Cheetah 15K.6 SAS Product Manual, Rev. B General description Media description Standard featuresPerformance Formatted capacities Factory-installed optionsReliability Programmable drive capacityCheetah 15K.6 SAS Product Manual, Rev. B Access time Performance characteristicsInternal drive characteristics Seek timeStart/stop time Format command execution time minutesGeneral performance characteristics 176 144 100Prefetch/multi-segmented cache control Cache operationCaching write data Prefetch operationRecoverable Errors Reliability specificationsError rates Unrecoverable ErrorsInterface errors Reliability and serviceSeek errors Preventive maintenancePerformance impact 4 S.M.A.R.TControlling S.M.A.R.T MillisecondsPredictive failures Reporting controlDetermining rate Thermal monitorDrive Self Test DST Temperature Log Page 0Dh Parameter Code DescriptionState of the drive prior to testing DST failure definitionShort test Function Code 001b Invoking DSTShort and extended tests Extended test Function Code 010bShipping Product warrantyAbort Product repair and return informationCheetah 15K.6 SAS Product Manual, Rev. B DC power requirements Physical/electrical specificationsAC power requirements ST3450856SS DC power requirementsST3450056SS FDE Gbit mode Amps ST3450056SS FDE DC power requirementsST3300656SS DC power requirements ST3300656SS Gbit mode AmpsST3300056SS FDE Gbit mode Amps ST3300056SS FDE DC power requirementsST3146356SS DC power requirements ST3146356SS Gbit mode AmpsST3146756SS FDE DC power requirements ST3146756SS FDE Gbit mode AmpsConducted noise immunity Power sequencingCurrent profiles Typical 450GB current profiles Typical 146GB current profiles Power dissipation ST3450856SS modelST3450056SS FDE model ST3300656SS model ST3300056SS FDE model ST3146356SS model ST3146756SS FDE model in 3 Gbit operation Temperature Environmental limitsShock and vibration Relative humidityEffective altitude sea level ShockPackage size Packaged/product weight Drop height Recommended mountingAcoustics Air cleanlinessVibration Corrosive environmentMechanical specifications Physical dimensions Cheetah 15K.6 SAS Product Manual, Rev. B Drive internal defects/errors Defect and error managementDrive error recovery procedures 51.87 Background Media Scan SAS system errorsMedia Pre-Scan Deferred Auto-Reallocation Idle Read After WriteDrive orientation InstallationCooling Air flow Drive mounting GroundingCheetah 15K.6 SAS Product Manual, Rev. B SAS features Interface requirementsDual port support Commands supported by Cheetah 15K.6 SAS family drives Scsi commands supportedCommand 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 Inquiry data Bytes Data hexMode Sense data 2.1 ST3450856SS/ST3450056SS Mode Sense data Mode Pages2.2 ST3300656SS/ST3300056SS Mode Sense data 2.3 ST3146356SS/ST3146756SS Mode Sense data Miscellaneous status Miscellaneous operating features and conditionsMiscellaneous features SAS physical interfacePhysical interface Datum B Physical characteristics Connector requirementsPin descriptions Pin Signal name Signal typeElectrical description SAS pin descriptionsSAS transmitters and receivers Signal characteristicsPower Ready LED OutGeneral interface characteristics LED drive signalDifferential signals Eye masks Eye masks overviewAbsolute amplitude Receive eye maskJitter tolerance masks Normalized time in UIJitter Peak-toSinusoidal Frequency in kHzTransmitter signal characteristics Signal characteristica Units GbpsSignal characteristic Units Gbps Receiver signal characteristicsMaximum allowable jitter Compliant jitter test pattern Cjtpat Impedance specificationsReceiver jitter tolerance Impedance requirements Sheet 1Impedance requirements Sheet 2 Transmitter characteristicsElectrical TxRx connections = -5,437dB Shows the zero-length test load Receiver characteristics Cheetah 15K.6 SAS Product Manual, Rev. B Presales Support Seagate Technology support servicesInternet Technical SupportData Recovery Services Authorized Service Centers Warranty ServiceData Recovery Services Call Center Toll-free Direct dial Index NumericsIraw SAS See also cooling