Seagate ST300MP0014 Savvio 15K.1 FC User Guide - Page 24

Unrecoverable Errors, Seek errors, Interface errors, Annualized Failure Rate AFR and Mean Time

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5.1.2 Unrecoverable Errors An unrecoverable data error is defined as a failure of the drive to recover data from the media. These errors occur due to head/media or write problems. Unrecoverable data errors are only detected during read operations, but not caused by the read. If an unrecoverable data error is detected, a MEDIUM ERROR (03h) in the Sense Key will be reported. Multiple unrecoverable data errors resulting from the same cause are treated as 1 error. 5.1.3 Seek 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, a seek positioning error (Error code = 15h or 02h) will be reported with a Hardware error (04h) in the Sense Key. Recoverable seek errors are specified at Less than 10 errors in 108 seeks. Unrecoverable seek errors (Sense Key = 04h) are classified as drive failures. 5.1.4 Interface errors An interface error is defined as a failure of the receiver on a port to recover the data as transmitted by the device port connected to the receiver. The error may be detected as a running disparity error, illegal code, loss of word sync, or CRC error. The total error rate for a loop of devices is the sum of the individual device error rates. 5.2 Reliability and service You can enhance the reliability of Savvio disc drives by ensuring that the drive receives adequate cooling. Section 6.0 provides temperature measurements and other information that may be used to enhance the service life of the drive. Section 8.1 provides recommended air-flow information. 5.2.1 Annualized Failure Rate (AFR) and Mean Time Between Failure (MTBF) The production disc drive achieves an AFR of 0.55% (MTBF of 1,600,000 hours) when operated in an environment that ensures the case temperatures do not exceed the values specified in Section 6.4.1. Operation at case temperatures outside the specifications in Section 6.4, "Environmental limits", may increase the product AFR (decrease the MTBF). The AFR is a population statistic not relevant to individual units. The AFR specification is based on the following assumptions for Business Critical Storage System environments: • 8,760 power-on hours per year • 250 average on/off cycles per year • Operating at nominal voltages • System will provide adequate cooling to ensure the case temperatures specified in Section 6.4 are not exceeded. Temperatures outside the specifications in Section 6.4 may increase the product AFR and decrease the MTBF. 5.2.2 Preventive maintenance No routine scheduled preventive maintenance is required. 16 Savvio 15K.1 FC Product Manual, Rev. B

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16
Savvio 15K.1 FC Product Manual, Rev. B
5.1.2
Unrecoverable Errors
An unrecoverable data error is defined as a failure of the drive to recover data from the media. These errors
occur due to head/media or write problems. Unrecoverable data errors are only detected during read opera-
tions, but not caused by the read. If an unrecoverable data error is detected, a MEDIUM ERROR (03h) in the
Sense Key will be reported. Multiple unrecoverable data errors resulting from the same cause are treated as 1
error.
5.1.3
Seek 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,
a seek positioning error (Error code = 15h or 02h) will be reported with a Hardware error (04h) in the Sense
Key. Recoverable seek errors are specified at Less than 10 errors in 10
8
seeks. Unrecoverable seek errors
(Sense Key = 04h) are classified as drive failures.
5.1.4
Interface errors
An interface error is defined as a failure of the receiver on a port to recover the data as transmitted by the
device port connected to the receiver. The error may be detected as a running disparity error, illegal code, loss
of word sync, or CRC error. The total error rate for a loop of devices is the sum of the individual device error
rates.
5.2
Reliability and service
You can enhance the reliability of Savvio disc drives by ensuring that the drive receives adequate cooling. Sec-
tion 6.0 provides temperature measurements and other information that may be used to enhance the service
life of the drive. Section 8.1 provides recommended air-flow information.
5.2.1
Annualized Failure Rate (AFR) and Mean Time Between Failure (MTBF)
The production disc drive achieves an AFR of 0.55% (MTBF of 1,600,000 hours) when operated in an environ-
ment that ensures the case temperatures do not exceed the values specified in Section 6.4.1. Operation at
case temperatures outside the specifications in Section 6.4, "Environmental limits", may increase the product
AFR (decrease the MTBF). The AFR is a population statistic not relevant to individual units.
The AFR specification is based on the following assumptions for Business Critical Storage System environ-
ments:
•
8,760 power-on hours per year
•
250 average on/off cycles per year
•
Operating at nominal voltages
•
System will provide adequate cooling to ensure the case temperatures specified in Section 6.4 are not
exceeded. Temperatures outside the specifications in Section 6.4 may increase the product AFR and
decrease the MTBF.
5.2.2
Preventive maintenance
No routine scheduled preventive maintenance is required.