>
High-Level Summary
With 40,000 hard drives, Backblaze knows a lot about the reliability of hard drives and shares the statistics:
78% of drives survive more than 4 years.
The median hard drive survives 6 years.
Drives have 3 distinct failure modes that follow a bathtub curve:
Early “Infant Mortality” Failure
Constant (Random) Failure
Wear Out Failure
As long as the temperature is within spec, reliability is not affected by heat.
HGST drives are generally reliable; Seagate and Western Digital hard drives’ reliability vary by model.