What is SMART? |

SMART (Self-Monitoring Analysis and Reporting Technology) is a feature on a computer's hard disk for providing various monitoring indicators of disk reliability. If SMART is enabled on a hard disk, the system administrator can receive analytical information from the hard drive to determine a possible future failure of the hard drive. SMART monitors a set of drive attributes, such as temperature, throughput performance and the number of hours the drive has been powered on. It compares these attributes to a corresponding set of thresholds. If an attribute drops below its threshold, the drive cannot guarantee that it will be able to meet its specifications in the future. Not all SMART attributes are available on all drives, however. It is up to the discretion of the drive manufacturers to decide on the set of SMART attributes to implement for the drive. The following is a brief description of some SMART terminology. Attribute An attribute is a particular property of a SMART enabled hard drive. Each attribute contains the following sub properties. ID The attribute ID. This is a non-zero positive number in the range 1-255 (0x01-0xFF). Description A textual description of the attribute. See "Understanding the SMART Attributes" for an explanation of the various SMART Attributes. Status Provided a status for the attribute. OK means the attribute value is in the safe zone and FAIL means that a Threshold Exceeding Condition has been detected. Value The attribute value is a normalized number measuring the attribute's relative reliability. The higher this value is, the more reliable the drive is. For some attributes, the value is normalized between 1 and 100, for others between 1 and 200. For some attributes (such as temperature), the attribute value is the actual non-normalized temperature in degrees Celsius. When an attribute value falls below the threshold, there is a chance that the drive cannot meet its specifications in the future. Worst For most attributes, this is the lowest normalized attribute value that has been recorded for this attribute. For temperature, it is the highest attribute value recorded. Threshold The threshold is a defined value in which an attribute should not exceed under normal operation. If the attribute value drops below the threshold for the drive, the normal operation of the drive cannot be guaranteed. Raw Value The raw value varies from attribute to attribute, but it generally represents a more meaningful measure of the attribute. It usually shows a count of the number of errors, hours, or times depending on the attribute in question. For instance, for the temperature attribute, it shows the degrees (in Celsius) of the drive. Predicted TEC Date This is the predicted date and time of the Threshold Exceed Condition (TEC). Prediction is based on the collected TEC data. See "Threshold Exceed Condition prediction" for more info.