It was one year ago that I first blogged about the failure rates of specific models of hard drives , so now is a good time for an update. At Backblaze, as of December 31, 2014, we had 41,213 disk drives spinning in our data center, storing all of the data for our unlimited backup service . That is up from 27,134 at the end of 2013. This year, most of the new drives are 4 TB drives, and a few are the new 6 TB drives. Let’s get right to the heart of the post. The table below shows the annual failure rate through the year 2014. Only models where we have 45 or more drives are shown. I chose 45 because that’s the number of drives in a Backblaze Storage Pod and it’s usually enough drives to start getting a meaningful failure rate if they’ve been running for a while. Backblaze Hard Drive Failure Rates Through December 31, 2014 Name/Model Size Number of Drives Average Age in years Annual Failure Rate 95% Confidence Interval HGST Deskstar 7K2000 (HDS722020ALA330) 2.0 TB 4,641 3.9 1.1% 0.8% – 1.4% HGST Deskstar 5K3000 (HDS5C3030ALA630) 3.0 TB 4,595 2.6 0.6% 0.4% – 0.9% HGST Deskstar 7K3000 (HDS723030ALA640) 3.0 TB 1,016 3.1 2.3% 1.4% – 3.4% HGST Deskstar 5K4000 (HDS5C4040ALE630) 4.0 TB 2,598 1.8 0.9% 0.6% – 1.4% HGST Megascale 4000 (HGST HMS5C4040ALE640) 4.0 TB 6,949 0.4 1.4% 1.0% – 2.0% HGST Megascale 4000.B (HGST HMS5C4040BLE640) 4.0 TB 3,103 0.7 0.5% 0.2% – 1.0% Seagate Barracuda 7200.11 (ST31500341AS) 1.5 TB 306 4.7 23.5% 18.9% – 28.9% Seagate Barracuda LP (ST31500541AS) 1.5 TB 1,505 4.9 9.5% 8.1% – 11.1% Seagate Barracuda 7200.14 (ST3000DM001) 3.0 TB 1,163 2.2 43.1% 40.8% – 45.4% Seagate Barracuda XT (ST33000651AS) 3.0 TB 279 2.9 4.8% 2.6% – 8.0% Seagate Barracuda XT (ST4000DX000) 4.0 TB 177 1.7 1.1% 0.1% – 4.1% Seagate Desktop HDD.15 (ST4000DM000) 4.0 TB 12,098 0.9 2.6% 2.3% – 2.9% Seagate 6 TB SATA 3.5 (ST6000DX000) 6.0 TB 45 0.4 0.0% 0.0% – 21.1% Toshiba DT01ACA Series (TOSHIBA DT01ACA300) 3.0 TB 47 1.7 3.7% 0.4% – 13.3% Western Digital Red 3 TB (WDC WD30EFRX) 3.0 TB 859 0.9 6.9% 5.0% – 9.3% Western Digital 4 TB (WDC WD40EFRX) 4.0 TB 45 0.8 0.0% 0.0% – 10.0% Western Digital Red 6 TB (WDC WD60EFRX) 6.0 TB 270 0.1 3.1% 0.1% – 17.1% Notes: The total number of drives in this chart is 39,696. As noted, we removed from this chart any model of which we had less than 45 drives in service as of December 31, 2014. We also removed Storage Pod boot drives. When these are added back in we have 41,213 spinning drives. Some of the HGST drives listed were manufactured under their previous brand, Hitachi.
Startup founders don’t usually pitch their ideas by admitting that they’re fixing something “boring,” but it seems to work for RevenueCat ‘s Jacob Eiting. In fact, Eiting alternately described his startup (which is part of the current class at accelerator Y Combinator) as handling “boring work” and solving a “boring problem.” RevenueCat helps developers manage their in-app subscriptions, which Eiting said “is just boring — developers don’t want to do it.” And yet it can be crucial for their business. After all, Eiting and his co-founder Miguel Carranza both worked at brain training app Elevate (where Eiting was CTO and Carranza was director of engineering), and he said shifting Elevate’s business model from one-off purchases to recurring subscriptions “saved the company.” Eiting left Elevate more than a year ago, ultimately deciding to build a startup around “this weird skill I have.” RevenueCat offers an API that developers can use to support in-app subscriptions on iOS and Android, which means they don’t have to worry about all the nuances, bugs and updates in the way each platform handles subscriptions. Eiting said this is the kind of thing that “holds a lot of companies back — maybe not forever, but it’s usually at a time when a company shouldn’t be worrying about this.” The API also allows developers to bring all the data about their subscription business together in one place, across platforms. Ultimately, he wants to turn RevenueCat into a broader “revenue management platform,” allowing developers to try out strategies like offering different prices to different customer segments. More broadly, Eiting suggested that subscriptions offer a way out of the current “race to the bottom in how software is sold” — particularly in mobile app stores, where many of us expect everything to be free or dirt cheap. Obviously, that’s not a great situation for someone hoping to make money by selling software, but Eiting pointed out that it can be bad for the consumer too, because it means the developer has less reason to support and update the app. “Someone who pays for your 99-cent app once, they think they own your time,” he said. “You want to be helpful, you don’t want to let down a paid user, but your incentives aren’t really aligned.” Subscriptions, even if they’re just for 99 cents a month, can re-align those incentives — Eiting has described this as a system of app patronage : “You want this thing to stay working, you need to pony up some money to developers.” He also acknowledged that as more apps shift to this model, there’s a risk of subscription fatigue , which could lead to “maybe not a harsh backlash, but there might be a secondary correction.” But in Eiting’s view, that’s less a problem for individual developers and more for the mobile platforms. Those platforms, he said, should be building better tools for consumers to manage all their subscriptions in one place.