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5.2.1Annualized Failure Rate (AFR) and Mean Time Between Failure (MTBF)
The product shall achieve an AFR of 0.63% (MTBF of 1,400,000 hours) when operated at nominal power and typical case temperatures of 40°C. Operation at temperatures outside the specifications in Section 6.5 may increase the product AFR (decrease MTBF). AFR and MTBF are population statistics that are not relevant to individual units.
The AFR and MTBF specifications are based on the following assumptions for business critical storage system environments:
•8760
•Operations at nominal voltages
•Temperatures outside the specifications in Section 6.5 may reduce the product reliability.
•A workload rate below the average annualized specified limits. Operation at excessive I/O duty cycle may degrade product reliability.
The enterprise application nearline environment of
Nonrecoverable read errors | 1 per 1015 bits read, max |
Annualized Failure Rate (AFR) | 0.63% (nominal power, 40°C case temperature) |
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Load unload cycles | 600,000 cycles |
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Rated Workload | Average rate of <550TB/year |
| The MTBF specification for the drive assumes the I/O workload does not exceed the |
| Average Annualized Workload Rate Limit of <550TB/year. Workloads exceeding the |
| annualized rate may degrade the drive MTBF and impact product reliability. The Aver- |
| age Annualized Workload Rate Limit is in units of TB per year, or TB per 8760 power |
| on hours. Workload Rate Limit = TB transferred * ( 8760 / recorded power on hours). |
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Warranty | To determine the warranty for a specific drive, use a web browser to access the |
| following web page: |
| From this page, click on the "Verify Your Warranty" link. You will be asked to provide |
| the drive serial number, model number (or part number) and country of purchase.The |
| system will display the warranty information for your drive. |
Preventive maintenance | None required. |
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5.2.2Hot plugging the drive
When a disk is powered on by switching the power or hot plugged, the drive runs a self test before attempting to communicate on its’ interfaces. When the self test completes successfully, the drive initiates a Link Reset starting with OOB. An attached device should respond to the link reset. If the link reset attempt fails, or any time the drive looses sync, the drive initiated link reset. The drive will initiate link reset once per second but alternates between port A and B. Therefore each port will attempt a link reset once per 2 seconds assuming both ports are out of sync.
If the
It is the responsibility of the systems integrator to assure that no temperature, energy, voltage hazard, 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.
5.2.3S.M.A.R.T.
S.M.A.R.T. is an acronym for
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NOTE | The drive’s firmware monitors specific attributes for degradation |
over time but can’t predict instantaneous drive failures. |
Each monitored attribute has been selected to monitor a specific set of failure conditions in the operating performance of the drive and the thresholds are optimized to minimize “false” and “failed” predictions.
CONSTELLATION ES.3 SAS PRODUCT MANUAL, REV. B | 13 |