Seagate ST336918N, ST318418N Reliability specifications, Error rates, Environmental interference

Less than 10 in 108 seeks

Less than 10 errors in 1012 bits transferred (OEM default settings) Less than 1 sector in 1015 bits transferred (OEM default settings) Less than 1 sector in 1021 bits transferred

800,000 hours

3 years

None required

Barracuda 36ES2 Product Manual, Rev. B 13

5.0Reliability specifications

The following reliability specifications assume correct host/drive operational interface, including all interface timings, power supply voltages, environmental requirements and drive mounting constraints (see Section 8.3).

Seek Errors

Read Error Rates [1]

Recovered Data

Unrecovered Data

Miscorrected Data

MTBF

Service Life

Preventive Maintenance

Note.

[1]Error rate specified with automatic retries and data correction with ECC enabled and all flaws reallocated.

5.1Error rates

The error rates stated in this specification assume the following:

•The drive is operated per this specification using DC power as defined in this manual (see Section 6.2).

•The drive has been formatted with the SCSI Format command.

•Errors caused by media defects or host system failures are excluded from error rate computations. Refer to Section 3.2, “Media Characteristics.”

•Assume random data.

5.1.1Environmental interference

When evaluating systems operation under conditions of Electromagnetic Interference (EMI), the performance of the drive within the system shall be considered acceptable if the drive does not generate an unrecoverable condition.

An unrecoverable error, or unrecoverable condition, is defined as one that:

•Is not detected and corrected by the drive itself;

•Is not capable of being detected from the error or fault status provided through the drive or SCSI interface; or

•Is not capable of being recovered by normal drive or system recovery procedures without operator interven- tion.

5.1.2Read errors

Before determination or measurement of read error rates:

•The data that is to be used for measurement of read error rates must be verified as being written correctly on the media.

•All media defect induced errors must be excluded from error rate calculations.

5.1.3Write errors

Write errors can occur as a result of media defects, environmental interference, or equipment malfunction. Therefore, write errors are not predictable as a function of the number of bits passed.

If an unrecoverable write error occurs because of an equipment malfunction in the drive, the error is classified as a failure affecting MTBF. Unrecoverable write errors are those which cannot be corrected within two attempts at writing the record with a read verify after each attempt (excluding media defects).

5.1.4Seek 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 ten recoverable seek errors in 108 physical seek operations. After detecting an initial seek error, the drive automatically performs an error recovery process. If the error recovery process fails, a seek positioning