Seagate ST9900805SS Savvio 10K.1 FC Product Manual - Page 24

Reliability and service

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5.1.3 Seek 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. 5.1.4 Interface errors An interface error is defined as a failure of the receiver on a port to recover the data as transmitted by the device port connected to the receiver. The error may be detected as a running disparity error, illegal code, loss of word sync, or CRC error. The total error rate for a loop of devices is the sum of the individual device error rates. 5.2 Reliability and service You can enhance the reliability of Savvio 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 8.1 provides recommended air-flow information. 5.2.1 Mean time between failures (MTBF) The production disc drive achieves an MTBF of 1,400,000 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. Operating the drive at case temperatures above these values will adversely affect the drive's ability to meet specifications (see Section 6.4, "Environmental limits"). Estimated power-on operating hours means power-on hours per disc drive times the total number of disc drives in service. Each disc drive must have accumulated at least nine months of operation. Data is 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 • Operating at nominal voltages • System provides adequate cooling to ensure the case temperatures specified in Section 6.4.1 are not exceeded. Drive failure means any stoppage or failure to meet defined specifications 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 a MTBF hit. 5.2.2 Preventive maintenance No routine scheduled preventive maintenance is required. 5.2.3 Hot plugging the drive Inserting and removing the drive on the FC-AL will interrupt loop operation. The interruption occurs when the receiver of the next device in the loop must synchronize to a different input signal. FC error detection mechanisms, character sync, running disparity, word sync, and CRC are able to detect any error. Recovery is initiated based on the type of error. 18 Savvio FC Product Manual, Rev. D

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18
Savvio FC Product Manual, Rev. D
5.1.3
Seek 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 10
8
seeks. Unrecoverable seek errors
(Sense Key = 04h) are classified as drive failures.
5.1.4
Interface errors
An interface error is defined as a failure of the receiver on a port to recover the data as transmitted by the
device port connected to the receiver. The error may be detected as a running disparity error, illegal code, loss
of word sync, or CRC error. The total error rate for a loop of devices is the sum of the individual device error
rates.
5.2
Reliability and service
You can enhance the reliability of Savvio disc drives by ensuring that the drive receives adequate cooling. Sec-
tion 6.0 provides temperature measurements and other information that may be used to enhance the service
life of the drive. Section 8.1 provides recommended air-flow information.
5.2.1
Mean time between failures (MTBF)
The production disc drive achieves an MTBF of 1,400,000 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. Operating the drive at case
temperatures above these values will adversely affect the drive’s ability to meet specifications (see Section 6.4,
"Environmental limits").
Estimated power-on operating hours means power-on hours per disc drive times the total number of disc
drives in service. Each disc drive must have accumulated at least nine months of operation. Data is 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
•
Operating at nominal voltages
•
System provides adequate cooling to ensure the case temperatures specified in Section 6.4.1 are not
exceeded.
Drive failure means any stoppage or failure to meet defined specifications 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
a MTBF hit.
5.2.2
Preventive maintenance
No routine scheduled preventive maintenance is required.
5.2.3
Hot plugging the drive
Inserting and removing the drive on the FC-AL will interrupt loop operation. The interruption occurs when the
receiver of the next device in the loop must synchronize to a different input signal. FC error detection mecha-
nisms, character sync, running disparity, word sync, and CRC are able to detect any error. Recovery is initiated
based on the type of error.