Seagate ST19171WC Product Manual - Page 28

Barracuda 9 Product Manual, Rev. C, Performance impact, Reporting control, Determining rate,

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18 Barracuda 9 Product Manual, Rev. C The purpose is to allow the customer to control when S.M.A.R.T. interruptions occur. As described above, forcing S.M.A.R.T by the RTZ command will reset the timer. Performance impact S.M.A.R.T. attribute data will be saved to the disc for the purpose of recreating the events that caused a predictive failure. The drive will measure and save parameters once every two hours subject to an idle period on the SCSI bus. The process of measuring off-line attribute data and saving data to the disc is uninterruptable and the maximum delay is summarized below: Maximum processing delay S.M.A.R.T. delay times On-line only delay DEXCPT = 0, PERF = 1 60 milliseconds Fully enabled delay DEXCPT = 0, PERF = 0 450 milliseconds Reporting control Reporting is controlled in the "Informational Exceptions Control Page" (1Ch). Subject to the reporting method, the firmware will issue to the "host" an 01-5D00 sense code. The error code is preserved through bus resets and power cycles. Determining rate S.M.A.R.T. monitors the rate at which errors occur and signals a predictive failure if the rate of degraded error rate increases to an unacceptable level. To determine rate, error events are logged and compared to the number of total operations for a given attribute. The interval defines the number of operations over which to measure the rate. The counter that keeps track of the current number of operations is referred to as the Interval Counter. S.M.A.R.T. measures error rate, hence for each attribute the occurrence of an "error" is recorded. A counter keeps track of the number of errors for the current interval. This counter is referred to as the Failure Counter. Error rate is simply the number of errors per operation. The algorithm that S.M.A.R.T. uses to record rates of error is to set thresholds for the number of errors and the interval. If the number of errors exceeds the threshold before the interval expires, then the error rate is considered to be unacceptable. If the number of errors does not exceed the threshold before the interval expires, then the error rate is considered to be acceptable. In either case, the interval and failure counters are reset and the process starts over. Predictive failures S.M.A.R.T. signals predictive failures when the drive is performing unacceptably for a period of time. The firmware keeps a running count of the number of times the error rate for each attribute is unacceptable. To accomplish this, a counter is incremented whenever the error rate is unacceptable and decremented (not to exceed zero) whenever the error rate is acceptable. Should the counter continually be incremented such that it reaches the predictive threshold, a predictive failure is signaled. This counter is referred to as the Failure History Counter. There is a separate Failure History Counter for each attribute. 5.2.8 Product warranty Beginning on the date of shipment to customer and continuing for a period of five years, Seagate warrants that each product (including components and subassemblies) or spare part that fails to function properly under normal use due to defect in materials on workmanship or due to nonconformance to the applicable specifications will be repaired or replaced, at Seagate's option and at no charge to customer, if returned by customer at customer's expense to Seagate's designated facility in accordance with Seagate's Warranty Procedure. Seagate will pay for transporting the repair or replacement item to customer. For more detailed warranty information, refer to the Standard Terms and Conditions of Purchase for Seagate products. Shipping When transporting or shipping a drive, a Seagate approved container must be used. Keep your original box. They are easily identified by the Seagate Approved Package label. Shipping a drive in a non-approved container voids the drive warranty.

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18
Barracuda 9 Product Manual, Rev. C
The purpose is to allow the customer to control when S.M.A.R.T. interruptions occur. As described above, forc-
ing S.M.A.R.T by the RTZ command will reset the timer.
Performance impact
S.M.A.R.T. attribute data will be saved to the disc for the purpose of recreating the events that caused a predic-
tive failure. The drive will measure and save parameters once every two hours subject to an idle period on the
SCSI bus. The process of measuring off-line attribute data and saving data to the disc is uninterruptable and
the maximum delay is summarized below:
Maximum processing delay
On-line only delay
Fully enabled delay
DEXCPT = 0, PERF = 1
DEXCPT = 0, PERF = 0
S.M.A.R.T. delay times
60 milliseconds
450 milliseconds
Reporting control
Reporting is controlled in the “Informational Exceptions Control Page” (1Ch). Subject to the reporting method,
the firmware will issue to the “host” an 01-5D00 sense code. The error code is preserved through bus resets
and power cycles.
Determining rate
S.M.A.R.T. monitors the rate at which errors occur and signals a predictive failure if the rate of degraded error
rate increases to an unacceptable level. To determine rate, error events are logged and compared to the num-
ber of total operations for a given attribute. The interval defines the number of operations over which to mea-
sure the rate. The counter that keeps track of the current number of operations is referred to as the Interval
Counter.
S.M.A.R.T. measures error rate, hence for each attribute the occurrence of an “error” is recorded. A counter
keeps track of the number of errors for the current interval. This counter is referred to as the Failure Counter.
Error rate is simply the number of errors per operation. The algorithm that S.M.A.R.T. uses to record rates of
error is to set thresholds for the number of errors and the interval. If the number of errors exceeds the threshold
before the interval expires, then the error rate is considered to be unacceptable. If the number of errors does
not exceed the threshold before the interval expires, then the error rate is considered to be acceptable. In
either case, the interval and failure counters are reset and the process starts over.
Predictive failures
S.M.A.R.T. signals predictive failures when the drive is performing unacceptably for a period of time. The firm-
ware keeps a running count of the number of times the error rate for each attribute is unacceptable. To accom-
plish this, a counter is incremented whenever the error rate is unacceptable and decremented (not to exceed
zero) whenever the error rate is acceptable. Should the counter continually be incremented such that it
reaches the predictive threshold, a predictive failure is signaled. This counter is referred to as the Failure His-
tory Counter. There is a separate Failure History Counter for each attribute.
5.2.8
Product warranty
Beginning on the date of shipment to customer and continuing for a period of five years, Seagate warrants that
each product (including components and subassemblies) or spare part that fails to function properly under nor-
mal use due to defect in materials on workmanship or due to nonconformance to the applicable specifications
will be repaired or replaced, at Seagate’s option and at no charge to customer, if returned by customer at cus-
tomer’s expense to Seagate’s designated facility in accordance with Seagate’s Warranty Procedure. Seagate
will pay for transporting the repair or replacement item to customer. For more detailed warranty information,
refer to the Standard Terms and Conditions of Purchase for Seagate products.
Shipping
When transporting or shipping a drive, a Seagate approved container must be used. Keep your original box.
They are easily identified by the Seagate Approved Package label. Shipping a drive in a non-approved con-
tainer voids the drive warranty.