Question: When I run into a a hard drive that may be failing, I scan it using ViVARD, which reliably lets me know if the drive needs replacing.
How do these sorts of tools work? How can they tell a bad sector from a good sector?
Answer: Modern hard drives implement a system in firmware called SMART. This system collects statistics on the drive performance, and automatically avoids data loss by moving data away from bad sectors.
Diagnostic tools query the hard drive’s SMART software to build a health check report.
Bad sectors are detected upon accessing the hard disk and are avoided and relocated by the SMART system.