Barracuda 18LP Family: ST39175LW/LC ST318275LW ... - Seagate
Barracuda 18LP Family: ST39175LW/LC ST318275LW ... - Seagate
Barracuda 18LP Family: ST39175LW/LC ST318275LW ... - Seagate
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<strong>Barracuda</strong> <strong>18LP</strong> Product Manual, Rev. E 13<br />
5.0 Reliability specifications<br />
The following reliability specifications assume correct host/drive operational interface, including all interface<br />
timings, power supply voltages, environmental requirements and drive mounting constraints (see Section 8.4).<br />
Seek Errors<br />
Read Error Rates [1]<br />
Recovered Data<br />
Unrecovered Data<br />
Miscorrected Data<br />
MTBF<br />
Service Life<br />
Preventive Maintenance<br />
Less than 10 in 10 8 seeks<br />
Less than 10 errors in 10 12 bits transferred (OEM default settings)<br />
Less than 1 sector in 10 15 bits transferred (OEM default settings)<br />
Less than 1 sector in 10 21 bits transferred<br />
1,000,000 hours<br />
5 years<br />
None required<br />
Note.<br />
[1] Error rate specified with automatic retries and data correction with ECC enabled and all flaws reallocated.<br />
5.1 Error rates<br />
The error rates stated in this specification assume the following:<br />
• The drive is operated per this specification using DC power as defined in this manual (see Section 6.2).<br />
• The drive has been formatted with the SCSI FORMAT commands.<br />
• Errors caused by media defects or host system failures are excluded from error rate computations. Refer to<br />
Section 3.2, “Media Characteristics.”<br />
5.1.1 Environmental interference<br />
When evaluating systems operation under conditions of Electromagnetic Interference (EMI), the performance<br />
of the drive within the system shall be considered acceptable if the drive does not generate an unrecoverable<br />
condition.<br />
An unrecoverable error, or unrecoverable condition, is defined as one that:<br />
• Is not detected and corrected by the drive itself;<br />
• Is not capable of being detected from the error or fault status provided through the drive or SCSI interface; or<br />
• Is not capable of being recovered by normal drive or system recovery procedures without operator intervention.<br />
5.1.2 Read errors<br />
Before determination or measurement of read error rates:<br />
• The data that is to be used for measurement of read error rates must be verified as being written correctly on<br />
the media.<br />
• All media defect induced errors must be excluded from error rate calculations.<br />
5.1.3 Write errors<br />
Write errors can occur as a result of media defects, environmental interference, or equipment malfunction.<br />
Therefore, write errors are not predictable as a function of the number of bits passed.<br />
If an unrecoverable write error occurs because of an equipment malfunction in the drive, the error is classified<br />
as a failure affecting MTBF. Unrecoverable write errors are those which cannot be corrected within two<br />
attempts at writing the record with a read verify after each attempt (excluding media defects).