Seagate ST336605LW/LC/LCV Performance impact, Milliseconds, Reporting control, Determining rate

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Cheetah 73LP Product Manual, Rev. E

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 disc 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 FC-AL bus. The process of measuring off-line attribute data and saving data to the disc is uninterruptable. The maxi- mum 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

50 milliseconds

300 milliseconds

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.

5.2.8Drive 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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Contents ST373405LW/LWV/LC/LCV ST336605LW/LC/LCV Page ST373405LW/LWV/LC/LCV ST336605LW/LC/LCV Page Revision status summary sheet Revision Date Writer/Engineer Sheets AffectedPage Contents Seagate Technology support services Defect and error managementInstallation Interface requirementsList of Figures Cheetah 73LP Product Manual, Rev. E ViiPage Scope Cheetah 73LP family drive ST373405LW shownCheetah 73LP Product Manual, Rev. E Applicable standards and reference documentation Taiwanese Bsmi Australian C-TickKorean MIC General description Cheetah 73LP family drive Performance Cheetah 73LP Product Manual, Rev. E Standard featuresMedia characteristics ReliabilityAccessories user installed Factory installed accessoriesOptions factory installed Unformatted and formatted capacitiesPerformance characteristics Prefetch/multi-segmented cache control Ultra2 Scsi Ultra3 ScsiStart/stop time Cheetah 73LP Product Manual, Rev. E Cache operation Caching write dataPrefetch operation Reliability specifications Service life Reliability and servicePreventive maintenance Service philosophy7 S.M.A.R.T Controlling S.M.A.R.TReporting control Performance impactMilliseconds Determining rateImplementation State of the drive prior to testingDST Failure Definition Invoking DSTExtended test Function Code 010b Short and extended testsShort test Function Code 001b Log page entriesProduct repair and return information Cheetah 73LP Product Manual, Rev. E Product warrantyShipping Cheetah 73LP Product Manual, Rev. E DC power requirements Physical/electrical specificationsAC power requirements 3 12 V Current profile Power sequencingConducted noise immunity Typical ST336605 drive +12 V current profile Typical ST336605 drive +5 V current profile Amperes 000 900 800 700 600 Relative humidity TemperatureCheetah 73LP Product Manual, Rev. E Environmental limits Effective altitude sea levelShock and vibration ShockRecommended mounting Acoustics Air cleanlinessVibration LW and LWV mounting configuration dimensions LC and LCV mounting configuration dimensions Drive internal defects Defect and error managementDrive error recovery procedures Scsi systems errors Formatting InstallationConfigure drive options Drive ID/option select headerDo not install jumpers retain cover J5 jumper header on LW/LWV models only J2 option select header Cheetah 73LP Product Manual, Rev. E Function description Does not apply to LC/LCV modelDrive orientation CoolingCheetah 73LP Product Manual, Rev. E Drive mounting GroundingCheetah 73LP Product Manual, Rev. E Interface requirements Scsi interface messages supportedScsi interface commands supported Cheetah 73LP Product Manual, Rev. E Cheetah 73LP Product Manual, Rev. E Inquiry Vital Product data Mode Sense data DEF CHG Cheetah 73LP Product Manual, Rev. E Condition/feature supported by Physical interface DC cable and connector2 REQ/ACK offset Pin Power Scsi interface physical description Scsi interface cable requirementsMating connectors for LC and LCV model drives Mating connectorsMating connectors for LW and LWV model drives ST373405LC/LCV and ST336605LC/LCVCheetah 73LP Product Manual, Rev. E Right-angle to Pcba connectors Scsi ID650±.005 155 100 346 Front View GND +DBP1 62Cheetah 73LP Product Manual, Rev. E REQ +REQ Multimode-SE and LVD alternatives LVD output characteristicsElectrical description General cable characteristics Single-ended drivers/receiversCables for low voltage differential drivers/receivers Terminator requirementsLC and LCV drives Disc drive Scsi timing Spindle status Command status LED status Drive activity LEDCheetah 73LP Product Manual, Rev. E Presales Support Seagate Technology support services Online ServicesAutomated Services Technical SupportEuropean Support Services Customer Service CSOUSA/Canada/Latin America Support Services Call Center Toll-free Direct dial Africa/Middle East Support ServicesAsia/Pacific Support Services Cheetah 73LP Product Manual, Rev. E Index Cheetah 73LP Product Manual, Rev. E Cheetah 73LP Product Manual, Rev. E Scam Scsi Scsi ID 80Cheetah 73LP Product Manual, Rev. E
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