Disk Drive Failures 15 Times What Vendors Say

jcatcw writes "A Carnegie Mellon University study indicates that customers are replacing disk drives more frequently than vendor estimates of mean time to failure (MTTF) would require.. The study examined large production systems, including high-performance computing sites and Internet services sites running SCSI, FC and SATA drives. The data sheets for the drives indicated MTTF between 1 and 1.5 million hours. That should mean annual failure rates of 0.88%, annual replacement rates were between 2% and 4%. The study also shows no evidence that Fibre Channel drives are any more reliable than SATA drives."

Repeat?

[Corith]

Didn't we already see this evidence with Google's report?

Personally I am SHOCKED

[dingbatdr]

Yes, I am SHOCKED that companies have implemented a systematic program of distorting the truth in order to increase profits.

I propose a new term for the heinous practice---"marketing".

Fuzzy math

[Spazmania]

Disk Drive Failures 15 Times What Vendors Say [...] That should mean annual failure rates of 0.88% [but] annual replacement rates were between 2% and 4%.

0.88 * 15 = 4?

Re:I believe it...

[SighKoPath]

Also, don't rely on the HDD before it surpasses its manufacturer warranty. All the warranty means is you get a replacement if it breaks - it doesn't provide any extra guarantees of the disk not failing.

I am shocked!

[Anonymous Coward]

I just can't believe that the same vendors that would misrepresent the capacity of their disk by redefining a Gigabyte as 1,000,000,000 bytes instead of 1,073,741,824 bytes would misrepresent their MTBF too! And by the way, nobody actually runs a statistically significant sample set their equipment for 10,000 hours to arrive at a MTBF of 10,000 hours, so isn't their methodology a little suspect in the first place?

Re:Interface matters why?

[ender-]

TFA seems surprised by SATA drives lasting as long as Fibre...why one earth would your data interface have any consequences on the drive internals? Or are we talking assuming Interface = Data Throughput?

That statement is based on the long-held assumption that hard drive manufacturers put better materials and engineering into enterprise-targeted drives [Fibre] than they put into consumer-level drives [SATA].

Guess not...

Seagate

[mabu]

After 12 years of running Internet servers, I won't put anything but Seagate SCSI drives in any mission critical servers. My experience indicates Seagate drives are superior. Who's the worst? Quantum. The only thing Quantum drives are good for is starting a fire IMO.

Re:I believe it...

[The Clockwork Troll]

In my experiences with several major drive vendors, I have never gotten an "upgrade". What you get is a replacement drive, but generally it's the same drive (perhaps refurbished or firmware-revised) and the original warranty period is still in effect (with perhaps a 30 day extension to account for your downtime). I've RMA'd a lot of drives and never have I gotten one of different spec/size. I'm not even sure this would be desirable, e.g. in the case of replacing a drive in a RAID array with something of different specification (yes, even "better" specification). Symmetry and everything.

Re:Masters of estimates

[Fulcrum of Evil]

Well, the hard-drive makers are correct on the size thing - a Gigabyte is 1000 Megabytes, and the OS and software makers are wrong.

Yeah, they coined the term and have been using it for 40 years, but they're wrong.

Gigabytes are actually displayed as Gigabytes, or that the listing is changed to correctly display Gibibytes as the value? (or Kibibytes, Mebibytes, whatever)

Listen, just because someone comes up with a standard doesn't obligate everyone to use it, especially when they already have a perfectly workable system already. Claiming that NIST can impose an unwanted standard on the world is like saying that it isn't a word until the OED lists it.

Re:Personally I am SHOCKED

[Timothy Brownawell]

Before computers were used in real engineering,

Computers have *always* been used for "real engineering" as you call it. It's only recently that they've gotten cheap enough to use as toys.

we could get away with "k" sometimes meaning 1024 (like in memory addresses) and sometimes meaning 1000 (like in network speeds). Those days are past.

WTF? It's like any other part of language, things have different meanings in different contexts. What does "cat" mean?

Now that computers are part of real engineering work, even the slightest amount of ambiguity is not acceptable .

Ok, so do we rename cat-the-program or cat-the-heavy-machinery (and what about cat-the-animal)? Computers and heavy machinery are both used for "real engineering work", so we can't have any ambiguity in which we're talking about. That would be not acceptable .

Differentiating between "k" (=1000) and "ki" (=1024) is a sign that the computer industry is finally maturing. It's called progress.

No, it's a sign that too many people have sticks up their butts and can't accept that language can be context-dependent. The world is not binary, and failing to recognize this is likely one reason that software sucks so much [technocrat.net].

Also, it's a sign that disks (as opposed to ram) are sized by cost, rather than efficient use of address lines. Ram is sold in power-of-2 sizes for technical reasons. Disks are different enough that those technical reasons aren't there, so marketing dictates that the prefixes used be chosen to give the largest numbers.

Re:I have thought the MTTF is bullshit for a while

[paeanblack]

The biggest reason I think it would make no difference is because if unconditioned power is supposed to be so bad for electronics then why is the only thing that I have a problem with turn out to be the hard drives? I would think bad power would take out RAM before a hard disk.

Ram has no significant inductive load.