Seagate ST34520N Product Manual - Page 24
Interface Product Manual
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14 Medalist Pro Product Manual, Rev. D 5.1.4 Seek errors A seek error is defined as a failure of the drive to position the heads to the addressed track. There shall be no more than one recoverable seek errors in 107 physical seek operations. After detecting an initial seek error, the drive automatically reseeks to the addressed track up to 3 times. If a reseek is successful, the Extended Sense reports a seek positioning error (15h), no seek complete error (02h), or track follow error (09h), and the sense key reports a recovered error (1h). If all three reseeks fail, a seek positioning error (15h) is reported with a Medium error (3h) or Hardware error (4h) reported in the Sense Key. This is an unrecoverable seek error. Unrecoverable seek errors are classified as failures for MTBF calculations. Refer to Section 5.1.1.2 of the SCSI Interface Product Manual (part number 77738479) for Request Sense information. Appendix A of this manual lists the sense keys and additional sense codes supported by the drives of this manual. 5.2 Reliability and service You can enhance the reliability of Medalist Pro disc drives by ensuring that the drive receives adequate cooling. Section 6.4.1 provides temperature measurements and other information that may be used to enhance the service life of the drive. Section 8.3.1 provides recommended air-flow information. 5.2.1 Mean time between failure The production disc drive shall achieve an MTBF of 800,000 hours when operated in an environment that ensures the case temperatures specified in Section 6.4.1 are not exceeded. Short-term excursions up to the specification limits of the operating environment will not affect MTBF performance. The following expression defines MTBF MTBF per measurement period Estimated power-on operating hours in the period = Number of drive failures in the period Estimated power-on operation hours means power-up hours per disc drive times the total number of disc drives in service. Each disc drive shall have accumulated at least nine months of operation. Data shall be calculated on a rolling average base for a minimum period of six months. Drive failure means any stoppage or substandard performance caused by drive malfunction. 5.2.2 Preventive maintenance No routine scheduled preventive maintenance shall be required. 5.2.3 Service life The drive shall have a useful service life of five years. Depot repair or replacement of major parts is permitted during the lifetime (see Section 5.2.4). 5.2.4 Service philosophy Special equipment is required to repair the drive HDA. In order to achieve the above service life, repairs must be performed only at a properly equipped and staffed service and repair facility. Troubleshooting and repair of PCBs in the field is not recommended, because of the extensive diagnostic equipment required for effective servicing. Also, there are no spare parts available for this drive. Drive warranty is voided if the HDA is opened. 5.2.5 Service tools No special tools are required for site installation or recommended for site maintenance. Refer to Section 5.2.4. The depot repair philosophy of the drive precludes the necessity for special tools. Field repair of the drive is not practical since there are no user purchasable parts in the drive.