One thing you can do when you have 25,000 consumer level HDDs running is to amass accurate data on the failure rates of drives.  Backblaze has done exactly that and published their findings which match fairly closely to the predicted MTBF pattern of a spike in the beginning of the life cycle as flawed drives fail, a long period of reliability followed by another rise in failures as drives age beyond their expected lifespan.  They have told the Register that they intend to follow up with tests on enterprise grade disks to see if the premium you pay is a good investment.

"Cloud backup outfit Backblaze has cobbled together all the data it's gathered from the 25,000 or so disk drives it keeps spinning and drawn some conclusions about just how long you can expect disks to survive in an array."

Here is some more Tech News from around the web:

Tech Talk