5.0Reliability specifications
The following reliability specifications assume correct host and drive operational interface, including all inter- face timings, power supply voltages, environmental requirements and drive mounting constraints.
Seek error rate: | Less than 10 errors in 108 seeks |
Read Error Rates1 |
|
Recovered Data | Less than 10 sector in 1012 bits transferred (OEM default settings) |
Unrecovered Data | Less than 1 sector in 1016 bits transferred |
Miscorrected Data | Less than 1 sector in 1021 bits transferred |
Interface error rate: | Less than 1 error in 1012 bits transferred |
MTBF | 1,600,000 hours |
Annualized Failure Rate (AFR) | 0.55% |
Preventive maintenance: | None required |
1.Error rate specified with automatic retries and data correction with ECC enabled and all flaws reallocated.
5.1Error rates
The error rates stated in this manual assume the following:
•The drive is operated in accordance with the manual using DC power as defined in Section 6.2.
•Errors caused by host system failures are excluded from error rate computations.
•Assume random data.
•Default OEM error recovery settings are applied. This includes AWRE, ARRE, full read retries, full write retries and full retry time.
5.1.1Recoverable Errors
Recoverable errors are those detected and corrected by the drive, and do not require user intervention.
Recoverable Data errors will use correction, although ECC
Recovered Data error rate is determined using read bits transferred for recoverable errors occurring during a read, and using write bits transferred for recoverable errors occurring during a write.
5.1.2Unrecoverable Errors
Unrecoverable Data Errors (Sense Key = 03h) are specified at less than 1 sector in error per 1016 bits trans- ferred. Unrecoverable Data Errors resulting from the same cause are treated as 1 error for that block.
5.1.3Seek errors
A seek error is defined as a failure of the drive to position the heads to the addressed track. After detecting an initial seek error, the drive automatically performs an error recovery process. If the error recovery process fails,
12 | Cheetah NS 10K.2 SAS Product Manual, Rev. C |