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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, 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.
5.2Reliability and service
You can enhance the reliability of Cheetah 10K.7 SCSI disc drives by ensuring that the drive receives ade- quate cooling. Section 6.0 provides temperature measurements and other information that may be used to enhance the service life of the drive. Section 8.3 provides recommended
5.2.1Annualized Failure Rate (AFR)
The production disc drive shall achieve an AFR of 0.62% when operated in an environment that ensures the HDA case temperatures specified in Section 6.4 are not exceeded.
Estimated
AFR is based on the following assumptions:
•8,760
•250 average on/off cycles per year.
•Operations at nominal voltages.
•Systems will provide adequate cooling to ensure the case temperatures specified in Section 6.4.1 are not exceeded.
Drive failure means any stoppage or substandard performance caused by drive malfunction.
A S.M.A.R.T. predictive failure indicates that the drive is deteriorating to an imminent failure and is considered an AFR hit.
5.2.2Preventive maintenance
No routine scheduled preventive maintenance shall be required.
5.2.3Hot plugging Cheetah 10K.7 SCSI disc drives
The ANSI
Case 1 - All bus devices powered off during removal or insertion
Case 2 - RST signal asserted continuously during removal or insertion
Case 3 - Current I/O processes not allowed during insertion or removal
Case 4 - Current I/O process allowed during insertion or removal, except on the device being changed
18 | Cheetah 10K.7 SCSI Product Manual, Rev. D |