S.M.A.R.T. is an acronym for Self-Monitoring, Analysis and Reporting Technology, which is a monitoring system for computer hard disk drives (HDDs) and solid-state drives (SSDs). It is useful for detecting and reporting fault conditions based on various indicators of reliability. The main aim of SMART is to monitor the disk status by using various methods and devices i.e. sensors.

Furthermore S.M.A.R.T. is an industry standard for monitoring and reporting fault conditions in a peripheral storage device. It is intended to decrease the chance of data loss by giving adequate warning messages; however, it cannot be a replacement for disaster-recovery planning.

When S.M.A.R.T. check anticipates a failure, user can take actions to safeguard data and choose to replace the drive to avoid the unexpected outage and data loss. According the S.M.A.R.T. specifications, when a problem is detected that is failure predicted, the hard disk will work for at least 24 hours during which user could perform the data backup.  The manufacturer can use this S.M.A.R.T. data to locate the faults and prevent them from recurring in future drive designs.

Attributes and Values

S.M.A.R.T. monitors the most important device parameters which are referred as attributes. In other words, attributes describe the measured value of hard drive controller operations. The values of an attribute are current, worst, threshold and raw. These values are generally normalized to a vendor specific scale that could be ranged up to 100, 200 or 253.

Threshold: This value marks the value at which the hard drive could fail.

Worst: This is the baddest value seen for this drive at this attribute.

Raw value: It is a vendor coded count that is given after decoding, the normal values like current, worst and threshold.

List of Important Attributes

There are numerous attributes of SMART. But, some of the attributes that are highly important and need quick attention are listed below.  

  • Read Error Rate: It stores the data that is related to the rate of hardware read errors occurred while reading data from a disk surface.
  • Reallocated Sector Count: Whenever the hard drive finds a read/write/verification error, it marks that sector as “reallocated” and transfers data to a special reserved area.
  • Spin Retry Count: This attribute stores a total count of the spin start attempts to reach the fully operational speed.
  • Command Timeout: It is the count of aborted operations due to HDD timeout.
  • Current Pending Sector Count: It is the count of the sectors that are waiting to be remapped, because of read errors which are also referred as “unstable” sectors.
  • Uncorrectable Sector Count: The total count of uncorrectable errors that were occurred when reading/writing a sector.
  • Soft Read Error Rate: It is a count of off-track errors.
Safe and Secure
Safe and Secure