File Server Builder's Guide
by Zach Throckmorton on September 4, 2011 3:30 PM ESTHard drives
One of the most frequently asked questions I hear is 'what's the most reliable hard drive?' The answer to this question is straightforward - the one that's backed up frequently. Home file servers can be backed up with a variety of devices, from external hard drives to cloud storage. As a general guideline, RAID enhances performance but it is not a backup solution. Some RAID configurations (such as RAID 1) provide increased reliability, but others (such as RAID 0) actually decrease reliability. A detailed discussion of different kinds of disk arrays is not within the scope of this guide, but the Wikipedia page is a good place to start your research if you're unfamiliar with the technology.
As for hard drive reliability, every hard drive can fail. While some models are more likely to fail than others, there are no authoritative studies that implement controlled conditions and have large sample sizes. Most builders have preferences - but anecdotes do not add up to data. There are many variables that all affect a drive's long-term reliability: shipping conditions, PSU quality, temperature patterns, and of course, specific make and model quality. Unfortunately, as consumers we have little control over shipping and handling conditions until we get a drive in our own hands. We also generally don't have much insight into a specific hard drive model's quality, or even a manufacturer's general quality. However, we can control PSU quality and temperature patterns, and we can use S.M.A.R.T. monitoring tools
One of the most useful studies on hard drive reliability was presented by Pinheiro, Weber, and Barroso at the 2007 USENIX Conference on File and Storage Technologies. Their paper, Failure trends in a large disk drive population, relied on data gleaned from Google. So while the controls are not perfect, the sample size is enormous, and it's about as informative as any research on disk reliability. The PDF is widely available on the web and is definitely worth a read if you've not already seen it and you have the time (it's short at only 12 pages with many graphs and figures). In sum, they found that SMART errors are generally indicative of impending failure - especially scan errors, reallocation counts, offline reallocation counts, and probational counts. The take home message: if one of your drives reports a SMART error, you should probably replace it and send it in for replacement if it's under warranty. If one of your drives reports multiple SMART errors, you should almost certainly replace it as soon as possible.
From Pinheiro, Weber, and Barroso 2007. Of all failed HDDs, more than 60% had reported a SMART error.
Pinheiro, Weber, and Barroso also showed how temperature affects failure rates. They found that drives operating at low temperatures (i.e. less than 75F/24C) actually have the highest (by far) failure rates, even greater than drives operating at 125F/52C. This is likely an irrelevant point to many readers, but for those of us who live further up north and like to keep our homes at less than 70F/21C in the winter, it's an important recognition that colder is not always better for computer hardware. Of use to everyone, the study showed that the pinnacle of reliability occurs around 104F/40C, from about 95F/35C to 113F/45C.
From Pinheiro, Weber, and Barroso 2007. AFR: Annualized Failure Rate - higher is worse!
Given the range of temperatures that hard drives appear to function most reliably at, it might take some experimentation in any given case to get a home file server's hard drives in an ideal layout.
So rather than answering what specific hard drive models are the most reliable, we recommend you do everything you can to prevent catastrophic failure by using quality PSUs, maintaining optimal temperatures, and paying attention to SMART utilities. For such small sample sizes as a home file server necessitates, the most important factor in long-term HDD reliability is probably luck.
Pragmatically, low-rpm 'green' drives are the most cost-effective storage drives. Note that many of the low-rpm drives are not designed to operate in a RAID configuration - be sure to research specific models. The largest drives currently available are 3TB, which can now be found for as little as $110. The second-largest capacity drives at 2TB generally offer the best $/GB ratio, and can regularly be found for $70 (and less when on sale or after rebate). 1TB drives are fine if you don't need much space, and can sometimes be found for as little as $40.
Facebook
Twitter
RSS
152 Comments
View All Comments
thesandbender - Monday, September 5, 2011 - link
It basically throws up a list of everything you could buy without providing any good reasons about why you should or should not. Can you really have the following in a 'buyer's' guide? "the most important factor in long-term HDD reliability is probably luck."Things that would have been nice to see:
1. Comparison of motherboard performance. Is a Dual 1.8ghz Atom enough to manage my RAID-5 array or do I need to pony up for a faster processor?
2. A real comparison of OS features and performance. This article just basically listed every OS and said "There are some good things... their are some bad things". Maybe benchmark each OS's performance as a SMB file share?
3. If one of your drive's reports an error... you should probably replace it. If it reports multiple errors, you should almost certainly replace it as soon as possible. Really? You think?
Most of the articles on Anandtech are pretty useful but this one smacks of a frantic attempt to finish a paper before class starts.
djc208 - Friday, September 9, 2011 - link
I would agree, especially about the OS section.Since a lot of the capabilities and stability of the system will be based on what OS you are running a little more in-depth look at each would have been nice.
I run and like the original version of WHS. I'm reluctant to move to 2011 since it's lost a lot of it's benefits and added too few new ones as far as I've seen. But if actually discussing OS's it's worth listing what they offer out of the box.
WHS does still offer easy integration and control from remote PCs, It does still handle client PC backups, and being Windows does allow you to do basically anything a windows PC will do with a little extra work.
Mine is running SageTV and ComSkip to handle all my DVR/media serving duties, and it has a few other services installed like eye-fi so I don't have to fire up a "normal" PC just to copy the files to the server anyway, just walk in the house and turn on the camera.
But knowing a little more about what is out there for alternatives would be nice in case I decide not to eventually go to WHS 2011.
kake - Monday, September 5, 2011 - link
What about using a rack mount style case? For example, right now we're looking at moving our current tower (with 8 drives in it) to this one (or something like it):http://www.newegg.com/Product/Product.aspx?Item=N8...
A 24 port hot swap 4U case provides plenty of expansion, ease of access to drives, and it doesn't have to be rack mounted as it comes with feet.
At 400 dollars, I don't know of anything that provides such a bang/buck combination.
Rick83 - Monday, September 5, 2011 - link
Well, you also need the rack, which itself is going to dump another few hundred dollars on you.Consider the Lian-Li PC-V343 (http://skinflint.co.uk/301329 - not sure which markets it's available in) which (with 6 hot swap front ends) also houses 24 hot swap hard drives (or 30, if you use 5-in-3s) and yet costs the same as the rack case, while being able to mount conventional hardware. In the end it will probably be a lot cheaper than going with a rack-mount.
Of course, if you already have a rack for your switch, router and domain server, then adding 4U's is relatively straightforward. For the home and small office (less than 24 clients), I'm not sure going rack is economical.
jrocks84 - Monday, September 5, 2011 - link
You don't actually need a rack for a single server, you can just put it on the ground. Also the Norco RPC-4224 has the hard drive racks included, with the Lian Li, you would have to buy 4 or 5 in 3 racks, nearly doubling the price. You also have to take into account that the total volume of the Lian Li is nearly 2x as much.MrCromulent - Monday, September 5, 2011 - link
Good for beginners, but to be honest I expected a little more depth from an Anandtech article. How about questions like:- Have all motherboard recommendations been positively tested to run under FreeBSD / FreeNAS? I my experience, FreeBSD is much more picky when it comes to SATA and network controllers than Linux and Windows.
- How much does (absence of) hardware-accelerated encryption impact transfer speeds on every processor mentioned?
- How important is ECC RAM? That's the reason I chose an Asus AM3 board for my file server. If you bother setting up a nice checksummed ZFS Raid, I would assume you also make sure your RAM has some parity check as well.
Rick83 - Monday, September 5, 2011 - link
Why?If you have ECC on the disk, do you still have to worry about RAM?
After all, data consistency should be given. At worst some cosmic ray will flip a bit of a kernel page and panic/crash, but that's exceedingly rare, and other hardware/software failures are more likely to send you into a crash than that.
ECC is nice if you actually fill your memory, for example in numerical simulation for engineering, you really don't want a flipped bit to impact the predicted tolerances, but if you already have an integrity check - why worry about RAM (on a fileserver)
Also, as you said, ECC is expensive: either you have to go AMD and pay for the extra electricty and not get AES acceleration, or you go Xeon and pay twice as much for mainboard and CPU as you normally would.
Currently I don't see ECC as an economically viable choice.
Death666Angel - Monday, September 5, 2011 - link
From what I read, if you have RAID and don't have a 500+ bucks RAID controller, your RAM will be used for parity stuff. I have read of 2 cases where people had a RAID5 and everything went fine until they all of a sudden couldn't read their data without any prior indication of a problem. Turned out, one of their RAMs was faulty. Haven't read anything of the sort happening with ECC RAM (though that is hardly a good amount of data, I agree ;-)).A lot of things are pretty rare, but that doesn't mean that you shouldn't take action to avoid them, if those actions are not that huge. For me, going the AMD route with ECC didn't cost any more than the Pentium/1155 route described here.
- Phenom II X4 840 + Asus M4A88TD-V EVO/USB3 + 8GB Kingston DDR3-ECC 1333MHz cost 223€.
- Pentium G620 + comparable Mainboard (ASUS P8H67) + 8GB DDR3 1333MHz RAM cost 159€
That's a 64€ difference (my system that costs 700€ without the HDDs, so with the Intel route I could have saved ~10%). That wouldn't have bought me a better RAID controller. And again, all the RAID people I talked to have indicated that doing RAID with parity without ECC RAM is akin to data suicide.
Performance wise there won't be much difference between the X4 and the Pentium if I tax them laxly. But with the 2 extra cores I have the possibility of running more services off my server in the future.
I'll also undervolt the CPU, so the power consumption will still be higher for the X4, but not by a lot.
As for AES, I don't need it and you don't get it in any sub 145€ Intel CPU anyway, so that's not any argument if you talk about ECC being too expensive.
Rick83 - Monday, September 5, 2011 - link
The i5 650 is below 135, actually, the cheapest Xeon is 20 euro more expensive.The ECC DDR3 is another ~20 euro more expensive. (in this case for the cheapest 3x1GB triple channel kit)
And finally, you've got to use a 1366 board, where the same 10 SATA ports are 70 euros more expensive.
(WTF, you can get an ASRock P55 extreme 4 for 110 euros! That's pretty insane.)
So, if you do do encryption, and/or want to go 32nm, then the difference is more than a 100 euros.
On a system that otherwise costs, for these components 275 euros.
25% more for something that induces a MBTF of over 9000!? (sorry, couldnt resist) - It's okay if you go AMD anyway, but for Intel ECC-ram is prohibitively expensive.
Flashfir - Monday, September 5, 2011 - link
Mine runs at around 26-33CArticle says best is around 40C?
Would I be correct in trying to up the hard drive temperatures to that range?