Backblaze’s analysis of nearly 40,000 drives showed five SMART metrics that correlate strongly with impending disk drive failure: SMART 5 – Reallocated_Sector_Count. SMART 187 – Reported_Uncorrectable_Errors. SMART 188 – Command_Timeout. SMART 197 – Current_Pending_Sector_Count. SMART 198 – Offline_Uncorrectable The 5 SMART stats that actually predict hard drive failure | Computerworld