S.M.A.R.T. is for Self-Monitoring, Analysis and Reporting Technology. First developed by Compaq, Hitachi, IBM, Maxtor, Quantum, Seagate, Toshiba and Western Digital, it has been adopted by almost every manufacturer. While an hard disk is running, its internal logic encounters events and reacts to them to fix unusual or unwanted situations. By keeping track of them, we can know that something sometimes didn't work fine with our hard disk. S.M.A.R.T. extends this philosophy by analyzing several parameters and reporting them. Data reported by S.M.A.R.T. can include the number of retries when transmitting data to the computer, the number of spare sectors that were used to replace bad ones, the number of times the hard disk has been started and stopped, the internal temperature and much more. S.M.A.R.T. relies on attributes, values and thresholds. Based on them, an hard disk might be about to fail.