Seagate ST373454 Manual download pdf (Page 24)

14 Cheetah 15K.3 SCSI Product Manual, Rev. G

error (15h) is reported with a 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 the

SCSI Interface

Product Manual,

part number 75789509, for Request Sense information.

5.2 Reliability and service

You can enhance the reliability of Cheetah 15K.3 SCSI 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 8.3 provides recommended air-flow information.

5.2.1 Mean time between failure

The production disc drive shall achieve an MTBF of 1,200,000 hours when operated in an environment that

ensures the HDA case temperatures specified in Section 6.4 are not exceeded. Short-term excursions up to

the specification limits of the operating environment will not affect MTBF performance. Continual or sustained

operation at case temperatures above the values shown in Section 6.4.1 may degrade product reliability.

The MTBF target is specified as device power-on hours (POH) for all drives in service per failure.

Estimated power-on operating hours in the period = MTBF per measurement 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.

MTBF is based on the following assumptions:

• 8,760 power-on hours per year.

• 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 MTBF hit.

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.

1 2 ... 19 20 21 22 23 24 25 26 27 28 29 ... 93 94

Comments to this Manuals

No comments

Seagate ST373454 Manual Page 24

Comments to this Manuals

Related products and manuals for Internal hard drives Seagate ST373454