Backblaze is a cloud backup and storage provider, it published its drive reliability numbers for Q4, and full year, of 2016. The company uses pods populated with 45 tor 60 hard disk for its storage needs. Each pod contains identical disks, but with a lot of them, different pods use different sizes and models. The report found that three 45-disk pods using 4TB Toshiba disks, and one 45-disk pod using 8TB HGST disks, went a full year without a single spindle failing. The numbers add up to more than 45 years of aggregate usage without a fault.
Toshiba’s drive spec sheet rates that model as having a 1-million-hour mean time to failure (MTTF). Mean time to failure or mean time between failures, (MTBF) are two numbers functionally identical. Over 2016, the measured disks accumulated 1.2 million hours of usage without failing.