Seagate ST3400755FC manual 4 S.M.A.R.T, Controlling S.M.A.R.T, Performance impact, Milliseconds

Page 27

The Pass-through state is disabled while the drive performs self test of the FC interface. The control line for an external port bypass circuit remains in the Enable Bypass state while self test is running. If the bypass circuit is present, loop operation may continue. If the bypass circuit is not present, loop operation will be halted while the self test of the FC interface runs.

When the self test completes successfully, the control line to the bypass circuit is disabled and the drive enters the FC-AL Initializing state. The receiver on the next device in the loop must synchronize to output of the newly inserted drive.

If the self-test fails, the control line to the bypass circuit remains in the Enable Bypass state.

Note. It is the responsibility of the systems integrator to assure that no temperature, energy, voltage haz- ard, or ESD potential hazard is presented during the hot connect/disconnect operation. Discharge the static electricity from the drive carrier prior to inserting it into the system.

Caution. The drive motor must come to a complete stop prior to changing the plane of operation. This time is required to insure data integrity.

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 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

42 milliseconds

163 milliseconds

Cheetah NS FC Product Manual, Rev. A

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Contents ST3400755FC ST3300955FC Cheetah NS FCPage Cheetah NS FC Product Manual, Rev. a Cheetah NS FC Product Manual, Rev. a Contents Defect and error management InstallationInterface requirements Seagate Technology support services Cheetah NS FC Product Manual, Rev. a List of Figures Page Scope Cheetah NS FC Product Manual, Rev. a Electromagnetic susceptibility Standards, compliance and reference documentsStandards Electromagnetic compatibilityCompliance Ncits TR-19 Reference documentsCheetah NS FC Product Manual, Rev. a General description Media description Standard featuresProgrammable drive capacity PerformanceReliability Formatted capacitiesUser-installed accessories Factory-installed optionsSeek performance Performance characteristicsInternal drive characteristics Access timeFormat command execution time minutes General performance characteristicsStart/stop time Prefetch/multi-segmented cache control Cache operationCaching write data Prefetch operation Unrecoverable Errors Reliability specificationsError rates Recoverable ErrorsPreventive maintenance Reliability and serviceSeek errors Interface errorsMilliseconds 4 S.M.A.R.TControlling S.M.A.R.T Performance impactThermal monitor Reporting controlDetermining rate Predictive failuresDST failure definition State of the drive prior to testingParameter Code Description Drive Self Test DSTExtended test Function Code 010b Invoking DSTShort and extended tests Short test Function Code 001bProduct repair and return information Product warrantyAbort ShippingCheetah NS FC Product Manual, Rev. a DC power requirements for ST3400755FC model Gbit Amps Physical/electrical specificationsAC power requirements DC power requirementsDC power requirements for ST3300955FC model Gbit Amps General DC power requirement notesConducted noise immunity Power sequencingCurrent profiles Cheetah NS FC Product Manual, Rev. a Random 8 Block Reads Power dissipationST3400755 CURRENT/POWER vs Throughput FC 4GB ST3400755FCST3300955FC ST3300955 CURRENT/POWER vs Throughput FC 4GBTemperature Environmental limitsRelative humidity Shock Package size Packaged/product weight Drop heightEffective altitude sea level Shock and vibrationRecommended mounting Corrosive environment Air cleanlinessVibration AcousticsChina Restriction of Hazardous Substances RoHS Directive X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。Mounting configuration dimensions Mechanical specificationsCheetah NS FC Product Manual, Rev. a Defect and error management Drive internal defects/errorsDrive error recovery procedures 77.87 FC-AL system errors Background Media ScanMedia Pre-Scan Idle Read After Write Deferred Auto-ReallocationCooling InstallationDrive ID/option selection Drive orientationAir flow Drive mountingGrounding Cheetah NS FC Product Manual, Rev. a Interface requirements FC-AL featuresFibre Channel link service frames Link services supported Type of frameFibre Channel task management functions Fibre Channel task management responsesFC Scsi FCP response codes Function name Response code NPort login Plogi payload Bytes Fibre Channel port loginProcess Login Plri payload Fibre Channel port login acceptFibre Channel Process Login NPort Login Accept ACC payload BytesFabric Login Flogi payload Bytes Fibre Channel Process Login AcceptFibre Channel fabric login Process Login Accept ACC payload BytesFabric Login Accept ACC payload Bytes Fibre Channel fabric accept loginOption Supported Dual port supportFibre Channel Arbitrated Loop options FC-AL options supportedSupported commands Command code Command name Scsi commands supportedVerify error recovery page 07h Cheetah NS FC Product Manual, Rev. a Temperature page 0Dh Mode Sense data Inquiry dataCheetah NS FC inquiry data Bytes Data hex Page Mode Sense 10 Byte Header Data Mode Data Header Miscellaneous status Miscellaneous operating features and conditionsMiscellaneous features Supported Feature or conditionPhysical characteristics FC-AL physical interfacePhysical description Connector requirements Electrical descriptionPin descriptions FC-SCA pin descriptions Pin Signal name Signal type Pin Signal name Signal typeFC-AL transmitters and receivers Fault LED Out PowerEnable port bypass signals Active LED OutMotor start controls 11 SEL6 through SEL0 ID lines Parallel Enclosure Services Interface ESISetting Arbitrated loop physical address Alpa valuesHex Dec Signal characteristics TTL input characteristicsDevice control codes LED driver signals FC Differential outputFC Differential input Receive eye diagram Eye diagram data values Link rate GHz Technical Support Seagate Technology support servicesInternet Presales SupportWarranty Service Data Recovery Services Authorized Service CentersData Recovery Services Call Center Toll-free Direct dial Numerics IndexFAN Flogi Plogi SEL ID See also cooling
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