Survival analysis for hard drives

How long do hard drives last?

Backblaze has kept up to 25,000 hard drives constantly online for the last four years. Every time a drive fails, they note it down, then slot in a replacement. After four years, Backblaze now has some amazing data and graphs that detail the failure rate of hard drives over the first four years of their life.

I guess it’s easier to do this with hard drives than it is for people.