S.M.A.R.T.

Self-Monitoring, Analysis and Reporting Technology is a capability built into the firmware of hard disk drives and solid-state drives that continuously records internal diagnostic counters called attributes. These attributes cover events such as reallocated sectors, pending uncorrectable sectors, spare block consumption on SSDs, read error rates, temperature excursions, power-on hours, and unsafe shutdown counts. The raw values and their thresholds are stored on the drive itself and can be read by the operating system and storage utilities; they appear in programs such as CrystalDiskInfo, vendor tools like Seagate SeaTools or Samsung Magician, and some motherboard firmware health screens at startup. Attribute names and raw value scales vary significantly between manufacturers and drive families, so comparing a Samsung NVMe value directly to a Western Digital Serial ATA value is not meaningful without consulting the specific model's documentation. A SMART warning does not indicate a driver problem and cannot be resolved by reinstalling or updating a storage driver package. It is a signal to copy all important data to a separate location immediately and evaluate whether the drive should be replaced, because the physical media is recording failures or degradation that software cannot repair. Some drives, particularly SSDs reaching the end of their rated write endurance, fail suddenly without any prior warning attribute crossing its threshold, which means a clean SMART report does not eliminate the need for regular backups. If a specific attribute such as Reallocated Sector Count or Wear Leveling Count reaches a vendor-defined critical level, treat the drive as unreliable even if the system still boots normally. Avoid running heavy write stress tests on a drive that is already reporting SMART warnings, as that additional load may accelerate failure before the data is safely copied.