Backblaze is transitioning from using 4 TB hard drives to 6 TB hard drives in the Storage Pods they will be deploying over the coming months.

Our 6 TB Hard Drive Face-Off
https://www.backblaze.com/blog/6-tb-hard-drive-face-off/

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.

The study’s not the best of guides to data centre performance, because Backblaze happily makes do with consumer-grade drives. As even those drives routinely offer mean time between failure (MTBF) in the hundreds of thousands of hours – decades of operation – or the storage industry’s preferred longevity metric of annualised failure rates (AFR) of under one per cent per year, the study tests those claims as well as any other

Backblaze’s study finds that both AFR and MTBF are bunk. The document finds that disks follow the predicted “bathtub” curve of failure: lots of early failures due to manufacturing errors, a slow decline in failure rates to a shallow bottom and then a steep increase in failure rates as drives age.

The study then looked at when drives fail and found a drive that survives the 5.1 per cent AFR of its first 18 months under load will then only fail 1.4 per cent of the time in the next year and half. After that, things get nasty: in year three a surviving disk has an 11.8 per cent AFR. That still leaves over 80 per cent of drives alive and whirring after four years, a decent outcome.

Hacked together NAS in a box
http://hackaday.com/2012/12/18/hacked-together-nas-in-a-box/

Want to launch your own high-capacity networked storage infrastructure? Backblaze just shared its new 180-terabyte Storage Pod design.

It was something of a PR stunt when the company shared its first-gen Storage Pod design back in 2009

Netflix was inspired to share its Open Connect Appliance Hardware design, and Backblaze also showed its Storage Pod 2.0 design, which could accommodate 135TB of data.

Now the Storage Pod 3.0 design is out, too. Backblaze uses 450 pods to hold more than 50 petabytes of customer data, it said.

The third-generation pods use 4TB drives — up to 45 of them — which increases the total capacity. Instead of being held in place by a band, they’re now squeezed by an anti-vibration panel that also shaves an hour off storage pod assembly time and makes it easier to replace failed drives.

The new design also switched to a Supermicro MBD-X9SCL-F motherboard, upgraded to a second-generation, lower-power Intel Core i3-2100 processor, improved airflow to keep components cool. The total cost for the pod — without drives — dropped to $1,942.59, $37.41 less than the second-gen Storage Pod.

Indeed, the cost per gigabyte is somewhat higher for new 4TB drives than for the earlier 3TB models it’s been using. But lower costs for power consumption, rack space, and installation mean the 4TB drives work out to be the same cost.