Seagate ST973352SS, ST973452SS, ST973252SS, ST9146752SS manual Predictive failures, Thermal monitor

Page 25

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.

6.2.5Thermal monitor

Savvio 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 65°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 65°C, however, you can set it to any value in the range of 0 to 65°C. If you specify a temperature greater than 65°C in this field, the temperature is rounded down to 65°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

 

 

Savvio 15K.2 SAS Product Manual, Rev. E

17

Page 24 Page 26
Image 25
Page 24 Page 26
Contents ST9146652SS ST973252SS ST9146852SSST9146752SS ST973452SSST973352SSStandard Models Self-Encrypting Drive Models SED Fips 140-2 ModelsPage Contents Installation Defect and error managementAbout Fips About self-encrypting drives Interface requirementsPage Savvio 15K.2 SAS Product Manual, Rev. E List of Figures Page Seagate Online Support and Services Seagate Technology support servicesScope Standards Applicable standards and reference documentationElectromagnetic compatibility Electromagnetic susceptibilityElectromagnetic compliance for the European Union Electromagnetic complianceAustralian C-Tick Korean MICEuropean Union Restriction of Hazardous Substances RoHS Reference documentsGeneral description Media description Standard featuresReliability PerformanceFormatted capacities Options Programmable drive capacityInternal drive characteristics Performance characteristicsSeek performance characteristics Access timeGeneral performance characteristics Format command execution timeStart/stop time Cache 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 Reporting controlPredictive failures Temperature Log Page 0Dh Parameter Code DescriptionThermal monitor Drive Self Test DST State of the drive prior to testingDST failure definition ImplementationShort test Function Code 001b Short and extended testsExtended test Function Code 010b Log page entriesShipping Product warrantyProduct repair and return information AC power requirements Physical/electrical specificationsDC power requirements Gbit mode Amps 146GB models DC power requirements73GB models DC power requirements Power sequencing General DC power requirement notesConducted noise immunity Current profile for 146GB models Current profilesCurrent profile for 73GB models 146GB models in 6.0 Gbit operation Power dissipation146GB models in 3.0 Gbit operation 73GB models in 3.0 Gbit operation 73GB models in 6.0 Gbit operationEnvironmental limits Temperature a. OperatingRelative humidity Shock and vibration Effective altitude sea level a. OperatingShock Recommended mounting Vibration a. Operating-normal Air cleanlinessCorrosive environment Acoustics Dimensions Mechanical specificationsPurpose About FipsLevel 2 security Admin SP Controlled accessAbout self-encrypting drives Data encryptionRandom number generator RNG Default passwordDrive locking Data bandsPower requirements Authenticated firmware downloadSupported commands Cryptographic eraseDrive internal defects/errors Defect and error managementDrive error recovery procedures SAS system errors Media Pre-Scan Background Media ScanDeferred Auto-Reallocation Idle Read After Write Drive orientation InstallationAir flow CoolingGrounding Drive mountingInterface requirements SAS featuresDual port support Supported commands Scsi commands supportedSupported commands Supported commands Supported commands Inquiry data Mode Sense dataSavvio inquiry data Page Mode Data Header 00 00 05 12 8B 00 10 Miscellaneous features Miscellaneous operating features and conditionsMiscellaneous status SAS physical interface Datum B Section C C Section a a Connector requirements Physical characteristicsElectrical description Pin descriptionsSAS transmitters and receivers SAS pin descriptionsSignal characteristics General interface characteristics SAS-2 Specification complianceAdditional information Savvio 15K.2 SAS Product Manual, Rev. E Numerics IndexIraw Msid Mtbf See also cooling
Top Page Image Contents