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11.8 S.M.A.R.T. Function
The intent of Self-monitoring, analysis, and reporting technology (S.M.A.R.T.) is to protect user data and prevent
unscheduled system downtime that may be caused by predictable degradation and/or fault of the device. By
monitoring and storing critical performance and calibration parameters, S.M.A.R.T. devices employ sophisticated
data analysis algorithms to predict the likelihood of near-term degradation or fault condition. By alerting the host
system of a negative reliability status condition, the host system can warn the user of the impending risk of a data
loss and advise the user of appropriate action.
Since S.M.A.R.T. utilizes the internal device microprocessor and other device resources, there may be some small
overhead associated with its operation. However, special care has been taken in the design of the S.M.A.R.T.
algorithms to minimize the impact to host system performance. Actual impact of S.M.A.R.T. overhead is dependent
on the specific device design and the usage patterns of the host system. To further ensure minimal impact to the user,
S.M.A.R.T. capable devices are shipped from the device manufacturer's factory with the S.M.A.R.T. feature
disabled. S.M.A.R.T. capable devices can be enabled by the system OEMs at time of system integration or in the
field by after-market products.
11.8.1 Attributes
Attributes are the specific performance or calibration parameters that are used in analyzing the status of the device.
Attributes are selected by the device manufacturer based on that attribute's ability to contribute to the prediction of
degrading or faulty conditions for that particular device. The specific set of attributes being used and the identity of
these attributes is vendor specific and proprietary.
11.8.2 Attribute values
Attribute values are used to represent the relative reliability of individual performance or calibration attributes.
Higher attribute values indicate that the analysis algorithms being used by the device are predicting a lower proba-
bility of a degrading or fault condition existing. Accordingly, lower attribute values indicate that the analysis algo-
rithms being used by the device are predicting a higher probability of a degrading or fault condition existing. There
is no implied linear reliability relationship corresponding to the numerical relationship between different attribute
values for any particular attribute.
11.8.3 Attribute thresholds
Each attribute value has a corresponding attribute threshold limit which is used for direct comparison to the attribute
value to indicate the existence of a degrading or faulty condition. The numerical value of the attribute thresholds are
determined by the device manufacturer through design and reliability testing and analysis. Each attribute threshold
represents the lowest limit to which its corresponding attribute value can be equal while still retaining a positive
reliability status. Attribute thresholds are set at the device manufacturer's factory and cannot be changed in the field.
The valid range for attribute thresholds is from 1 through 253 decimal.
11.8.4 Threshold exceeded condition
If one or more attribute values are less than or equal to their corresponding attribute thresholds, then the device
reliability status is negative, indicating an impending degrading or faulty condition.
11.8.5 S.M.A.R.T. commands
The S.M.A.R.T. commands provide access to attribute values, attribute thresholds and other logging and reporting
information.
Travelstar 7K100 Hard Disk Drive Specification
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