Function; Attributes; Attribute Values; Attribute Thresholds - IBM DTTA-351010 - Deskstar 10.1 GB Hard Drive Specifications

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Figure 66. Power conditions
Ready(RDY) is not a power condition. A device may post ready at the interface even though the media may
not be accessible.
10.6 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 con-
dition. 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.

10.6.1 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.

10.6.2 Attribute values

Attribute values are used to represent the relative reliability of individual performance or calibration attri-
butes. The valid range of attribute values is from 1 to 253 decimal. Higher attribute values indicate that the
analysis algorithms being used by the device are predicting a lower probability of a degrading or faulty condi-
tion existing. Accordingly, lower attribute values indicate that the analysis algorithms being used by the
device are predicting a higher probability of a degrading or faulty condition existing.

10.6.3 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 attri-
bute 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.

10.6.4 Threshold exceeded condition

If one or more attribute values, whose Pre-failure bit of their status flag is set, are less than or equal to their
corresponding attribute thresholds, then the device reliability status is negative, indicating an impending
degrading or faulty condition.
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General Operation Descriptions
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