S.M.A.R.T. - Self-tests

Self-tests

SMART drives may offer a number of self-tests:

Short

Checks the electrical and mechanical performance as well as the read performance of the disk. Electrical tests might include a test of buffer RAM, a read/write circuitry test, or a test of the read/write head elements. Mechanical test includes seeking and servo on data tracks. Scans small parts of the drive's surface (area is vendor-specific and there is a time limit on the test). Checks the list of Pending sectors that may have read errors. (Usually under two minutes.)

Long / Extended

A longer and more thorough version of the short self-test, scans the entire disk surface, with no time limit. (Hundreds of minutes, approximately one gigabyte per minute for modern drives.)

Conveyance

Intended as a quick test to identify damage incurred during transporting of the device from the drive manufacturer to the computer manufacturer. Only available on ATA drives. (Several minutes.)

Selective

Some drives allow selective self-tests of just a part of the surface.

The self-test logs for SCSI and ATA drives are slightly different. It is possible for the long test to pass even if the short test fails.