How long do consumer level hard drives last?

Many of us have had hard drives fail.  And stories of dead drives are commonplace around the net.  But for the most part these have been anecdotal accounts, with very little hard data for comparison.  Backblaze, an online data storage company, has released a study examining their 25,000 hard  drives over a  period of four years.

Backblaze runs their drives twenty-four hours a day, and the majority of their 75 petabytes of data capacity is made up of consumer grade internal hard drives, but 6 petabytes of that use external drives that were removed from their cases due to the shortage of drives caused by flooding in Thailand.

Their results show that hard drives are fairly reliable during their first three years.  There are basically three stages of failure.  During the first 1.5 years, drives fail at a rate of 5.1% annually.  During the next 1.5 years, the drives fail at 1.4% annually and after 3 years the failure rate jumps dramatically to 11.5%.  Extrapolating from that data, Backblaze expects a 50% total failure rate for their consumer level drives at the 6 year mark.



Backblaze promises to update their findings every quarter and will be examining durability of enterprise drives in comparison to consumer grade drives as well.

You can find the entire story at the Backblaze blog.