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Hard Drive Reliability Update – Sep 2014

backblaze.com

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Re: Hard Drive Reliability Update – Sep 2014

#91
post #69

Question for the OP here (or for anyone else). Do you burn in new drives before using? I typically will take any new drive and do some type of stress test [1] on it for 18 to 24 hours to see if it fails with that initial constant use. [1] Constant reformatting for example writing 0's to the entire disk 7 times etc.

Yev from Backblaze here -> Yes, we do burn in the drives before deploying them. So the drives in the study are ones that have at least made it past that state.

Re: Hard Drive Reliability Update – Sep 2014

#92
post #57
post #10

I wish there was something similar for SSDs.

After a few hundred drives, our anecdata is that failure over time on SSDs is generally related to drive endurance. Make sure you use a SMART utility which can read (and translate to English) the current net usage of the drive. Throw them away when you get to 100% usage. I recently examined a set of Crucial m4s which were at 130% of usage. There was no lost data, but write bandwidth was hilariously bad (around 10-20M…

It sounds like you might not have TRIM enabled? Or am I misunderstanding what you mean by 'usage'?

Re: Hard Drive Reliability Update – Sep 2014

#93

Biggest takeaway was at the end, with the "enterprise" drives being slightly less reliable than the consumer ones at half the cost.

I don't believe reliability has ever necessarily been an "enterprise" feature. The concrete features I understand "enterprise" drives as having are: 1) firmware is built with RAID in mind. This might sound weird, but consumer drives are more likely to have problems with RAID, just because they aren't designed for it. See, for example, the first WD Green drives crashing RAID clusters because some timeout was too high.…

At every sales-pitch I've ever attended, the enterprise vendors mention “reliability” about every other word – the message that your boss will fire you for taking risks unless you buy their hardware is communicated with the subtlety of a solar eclipse.

As for the RAID point, you'd very much want to find real data for that. I've heard similar folklore but have also heard plenty of lost data stories from enterprise disks in enterprise RAID. If I were building out a large storage farm, I'd strongly consider forgoing hardware RAID altogether and using something like ZFS so it'd be observable.

Re: Hard Drive Reliability Update – Sep 2014

#95
post #61
post #41

Earlier quoted context omitted.

I'm so ashamed right now. I've been recommending Seagates to everybody who asked for years without updating my fundaments...

Yev from Backblaze here -> No reason to be ashamed! Truth is we still buy Seagates! Most likely they will work well enough in a home environment. All drives fail eventually. If you can get 3-4 years out of one, that's great!

Yes but usually people come to me because I'm the tech guy and they expect something better then "Take whatever you want. They'll all make it through the first 3-4 years" ;)

The worst part of it is: my own HDs are all Seagates and I use them longer then that...

Re: Hard Drive Reliability Update – Sep 2014

#96
post #42
post #18

Earlier quoted context omitted.

My small datacenter results mimic BackBlaze too. Dead/dying seagates all over the place. So I notified management that we will only be purchasing Hitachi drives from now on. I have a BackBlaze server that I recently converted to FreeBSD & ZFS. I love the drive-density that Backblaze offers but I HATE the lack of physical notification when a drive dies. Most ofther file-servers have a front-facing drive caddy, that us…

You definitely don't want to use drives from the same manufacturing run (batch) on the same array, since they are the most likely to fail all at the same time. Second to that, you probably don't want to go single-source for your drives -- maybe use Hitachi with a mix of WD.

> Second to that, you probably don't want to go single-source for your drives -- maybe use Hitachi with a mix of WD.

Can you explain why not?

Re: Hard Drive Reliability Update – Sep 2014

#97
post #14

Since annual failure rate is a function mostly of age, it would be interesting to see a line chart of cumulative failure rate vs age. But since new drives are continually being added to the population, there would be fewer drives in the data set as you moved up each curve. I guess you could calculate confidence intervals at quarterly intervals, and so the error bars would get larger as age increases and 'n' decreases…

> Since annual failure rate is a function mostly of age, it would be interesting to see a line chart of cumulative failure rate vs age

They showed some of this data in an earlier post https://www.backblaze.com/blog/how-long-do-disk-drives-last/

The "Drives have 3 distinct failure rates" graph is the most interesting, as it shows the result of the expected "bathtub curve" on the cumulative failure rate.

Re: Hard Drive Reliability Update – Sep 2014

#98
post #94

Hard drive age a bad parameter to use. It should be the hours the drive was actually powered on.

I have a feeling that with Backblaze that ALL of their drives are mostly powered on continuously until they fail (i.e. they might sit for a bit at their data center waiting to go into one of their pods, but after that they pretty much run until they fail).

Re: Hard Drive Reliability Update – Sep 2014

#99
post #77

I really want to applaud backblaze for publishing these reports and stats. Too many companies closely guard this information that really helps the larger community. Based on the previous blogs from backblaze, when I built out our new hadoop cluster, I purchased 1450 Hitachi drives. I plan to gather our failure rates and publish them as backblaze does. Thanks for blazing the path!

Yev from Backblaze -> Thanks! That really is one of our goals with these updates, is for others to join us and start sharing this data. It makes a lot more sense if everyone is doing it, then we can start comparing environments, and all sorts of fun stuff!

Re: Hard Drive Reliability Update – Sep 2014

#100
post #98
post #94

Hard drive age a bad parameter to use. It should be the hours the drive was actually powered on.

I have a feeling that with Backblaze that ALL of their drives are mostly powered on continuously until they fail (i.e. they might sit for a bit at their data center waiting to go into one of their pods, but after that they pretty much run until they fail).

If thats the case, okay. Obviously still not ideal - you would want to have even IO load distribution on all drives - but hey, better than nothing.
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