How Soon Will Your Hard Drive Fail?

Category: Hard-Drives

A common question is "How long will my hard drive last?" It's a very good question, but it might be the wrong question. Read on for some stats on the life expectancy of a hard drive, and find out the more important question you should be asking yourself...

Hard Drive Life Expectancy (and the Right Question)

Whenever I am asked, “How long can I expect a hard drive to last?” I reply with, “How often do you back up your data?” This seeming non sequitur perplexes people, but I have found that the answer to my question is, almost invariably, the reason the first question is asked. The questioner is wondering how much longer he/she can get away with not backing up data.

Technobabble about MTBF (Mean Time Between Failure) in the 50,000 to 100,000 hour range is useless. Those hours are active hours during which the read/write head of the drive is moving. You have no way to monitor and record read/write head activity and you don’t want to be bothered doing so unless you’re a test engineer for a hard drive manufacturer.

Hard Drive Life Expectancy

Furthermore, MTBF measures mean (average) time before the hardware fails catastrophically, as in “won’t spin anymore.” That is the very last thing that will go wrong with a hard drive, akin to throwing a rod in your car’s engine. Long before the hardware fails catastrophically, you will be experiencing losses of data, and you might not even notice that it's happening.

When data is written to a drive, the magnetic charge of tiny areas of the physical disk is altered. One magnetic state means “0” or zero, the other means “1” or one… or on/off, if you prefer. The patterns of this binary code store your data as a collection of magnetized spots in one state or the other. In order to make the disk reusable, the magnetic state of each spot on it must be changeable.

A lot of things can change that magnetic state beside the drive’s read/write head. A strong magnetic field near a drive can scramble data. Power blips can cause a read/write head to write (change the magnetic state of a spot) instead of read, overwriting data with gibberish. Even cosmic rays can penetrate any computer case and zap the data on a hard drive, although a cosmic ray is so narrow it will probably affect only one or a handful of data spots.

You don't believe in cosmic rays? As I like to say, choosing not to believe in something doesn't make it go away. But no matter -- natural disasters like fires, floods, hurricanes and tornados also tend to dramatically shorten the lifespan of a hard drive. Even if your brand new 2 terabyte hard drive has no manufacturing defects, it won't last long in an F5 tornado packing 200 MPH winds. And of course, there are well-known threats from viruses, botnets, and ransomware.

So a hard drive is in constant danger of having all or part of its data either erased, corrupted, destroyed, or otherwise rendered unreadable. It doesn’t matter if the drive is fresh out of the box or nearing its MTBF. (That list of destructive actions reminded me of another phrase: “Do Not Fold, Spindle or Mutilate”. I searched for that and found an interesting 100-year history of the punch card. You might enjoy reading Do Not Fold, Spindle or Mutilate: A Cultural History of the Punch Card.)

What Studies Have Been Done on Hard Drive Life Expectancy?

A study on hard drive longevity was conducted by Backblaze, an online backup provider that has more than 25,000 consumer-grade hard drives in service. They found that 78% of the drives they use are lasting longer than four years. That might sound good, but it also implies that 22% of hard drives fail in the first four years.

The Backblaze study identifies the three most common causes of drive failure: factory defects, random failures, and parts that wear out. The failures due to factory defects tend to happen in the first 18 months of service. Failures due to wear out start to increase much faster after the three-year point.

The Backblaze study has been ongoing for several years. Other hard drive studies done by Google and Carnegie-Mellon University have been five-year spans, and both were conducted in 2007. So there just isn't an authoritative answer as to how long a hard drive will last. Backblaze has some stats that give them confidence to predict that more than half of all drives will last six years. I think you'll find their report interesting.

What Are the Implications?

Let me summarize and pontificate a bit. About one in five hard drives will fail within four years. Failure rates start to jump after three years. And there's a 50/50 chance your drive will last six years. Does that give you a warm fuzzy feeling? I'd rather not rely on luck and statistics. My advice is simple... why take chances?

It's vital to back up your data regularly and not just whenever you don’t feel like doing something else. Regular, automatic backups are the best defense you have against loss of data. Your thoughts are welcome on this topic! Post your comment or question below...

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Most recent comments on "How Soon Will Your Hard Drive Fail?"

Posted by:

John Wood
24 Oct 2019

Thank you Bob for this detailed and rational explanation of why backing up your hard drive is the best way to save your information.

Posted by:

Cold City
24 Oct 2019

Backup are so important! I have a friend who had written very many notes in studying her bible (physical book), hundreds of notes, then the bible was lost no back up obviously...
Online back up are great but do require a fast upload Internet connection!
Thanks for the warning! I'll get busy in buying new drives and make 2 copies. (That being much cheaper than high speed upload - especially in Canada...)

Posted by:

Eric Lenhart
24 Oct 2019

Don't forget about that back up drive hiding somewhere, they fail too.

Posted by:

David Mandel
24 Oct 2019

I guess I am a bit paranoid. I backup whenever I feel that there has been enough additions and deletions. As a strictly home user that isn't too often. I use SyncToy to backup the most changeable and important files (e.g. document, photos, recipes,etc.) on my working hard drive and then I backup the backup drive to a second drive. Less often I make a mirror image of both the c: and d; drives using Macrium. Finally, I keep a copy of our very important recipes folder on Onedrive (we share the recipe files with family) and I take advantage of my Amazon Prime membership to back up my photo files.

Posted by:

24 Oct 2019

I back up my three main (meaning actually used for much) computers to external hard drives every Saturday night. (Yes, Saturday night. My outside life is, well...) Of those three computers, one has periods of doing nothing, with the fan whirring furiously. (And it's on its second hard drive.) Another works fine, but clunk-clunks every so often. The third also works fine, but one can hear a very faint but continuous cck-cck-cck on every startup. To echo you, Bob, BACKUP!

Posted by:

24 Oct 2019

I have to question the validity of those stats. I have been using laptops and 6 pc's at any given time for at least 25+ years so 150 computer years. I have never had a hard drive fail. If the 50%/ 6 year stat were correct, I should have had multiple failures by now.

Posted by:

24 Oct 2019

I do an image back up all of our hard/solid state drives on our home network weekly. Being an IT professional for 30+ years, I learned a long time ago that, you don't need to back anything up...until you wish you did.

Posted by:

Louie O.
24 Oct 2019

Whenever I click on the link to this site from my Inbox, I am redirected to a full page scam popup after about 5 seconds. If I enter the URL manually I am not redirected. Anyone else having this issue? This has been happening here for the last ten days or so.

EDITOR'S NOTE: Sounds like something is hijacking your email links. Have you run a malware scan?

Posted by:

24 Oct 2019

Coincidentally, the successor to punch cards has just been replaced by the US air Force.

Posted by:

24 Oct 2019

I have gone thru thousands of hard drives (yes really - since 1980) I have had them die in 2 days and some lasting over 15 years. My 5mb (MB not GB) Tandy Hard drive is still working! Bought it in 1981 and only cost $2495 ($7263 in today's money). Think your hard drive will last that long? Nope! BACKUP!

Posted by:

jim scofield
24 Oct 2019

I don't think it happens so much anymore, but there is also the accidental "Reformat Drive?" "Yes." But that's not the drive failing, but rather the driver.

Posted by:

25 Oct 2019

I use crystaldiskinfo:-
Stablebit Scanner:-

to monitor my drives. Then I bought a DAS & installed:-
Stablebit Drivepool

to organize the data in my DAS. If stable bit scanner detects an soon to be dead drive, I just remove it & then install a new drive and Stablebit Drivepool will then re-organize the new drive into the drive pool. It is a stunning bit of software. I do not have to have multiple back-ups, I just have one DAS, or you can add another DAS. This is the DAS I bought:-

It holds 8 drives, so 8 drives times 10TB drives is 80TB's & with drivepool, the usable space after their internal back-up is half of 80TB, 40TB; that is a lot of data it can hold in 1 DAS. I can have it on, if I boot to my everyday drive or leave it off if I boot into my games drive. It is a lovely DAS as it has fans to keep all the drives cool & it transfers at USB 3.0 or if you use eSata connection to transfer files. It is very easy to set-up with the Stablebit software, and if you have any triuble, the owner always monitors the forum at that URL site

Disclaimer:- I am not attached to any drive or software or DAS at all, I am just a very happy user :)

Posted by:

top squirrel
25 Oct 2019

I have to echo Bart's comment. I've been into computers for about 20 years and I have never had a hard drive fail. Once, a motherboard failed but the HD was rescued and lives on.
I wonder how many readers of this newsletter have actually sustained a hard drive failure.
How many readers have actually lived through a house fire that destroyed everything? It doesn't mean you shouldn't have fire insurance but it makes sense not to freak out at the prospect of every conceivable danger and keep things in perspective.
After all, qwertyuiop[]asdfghjkl;1234567890-zxcvbnm,./, eh?
(Sorry, couldn't resist!)
Backing up every week or thereabouts would take so much time and money I might as well gravitate back to paper files using the computer as just a word processor. And external hard drives do cost money.

EDITOR'S NOTE: I've had a couple of drives go bad. I see 1 terabyte external hard drives for about $30 now. And if you configure your backup software to make automatic backups, the time factor is moot.

Posted by:

Daniel Wiener
26 Oct 2019

Thank you, Bob, for your constant harping on the importance of back-ups. Even though I've not had any recent losses, I remain paranoid about protecting my data. There's a lot of valuable and irreplaceable information on my computer. I have various hard drive and USB backups (and in times past backed up onto DVDs and CDs). But I still find it hard to remember to back things up every day.

So I finally took your advice (and special offer) and ponied up the money for iDrive's cloud backup service. After more than a year of using it, I realized that psychologically it's a load off my mind to not have to worry about data losses.

I recently noticed that my iDrive account can include multiple computers and cell phones. Since I still have over 300 GB of available cloud storage, I'm now also backing up my cell phone, and I'm trying to goad my daughter into backing up her PC and phone.

Posted by:

27 Oct 2019

I have an Amiga 3000 with the original HD of about 60 megs (yes, megs! - Amigas are parsimonious)and a second 1 gig. HD and both are still working after 20 years or so.

My laptop is not quite 7 years old and the HD is still working. (Yes, I back it up regularly.)

Posted by:

Bill d
11 Jun 2021

My wife & I have two external drives each, backing up every day. One backs up only our photos, since we are photographers. In your opinion, are we overdoing it backing up every day, as opposed to once weekly? How often is everyone backing up?

Posted by:

Lawrence Rayburn
06 Mar 2023

Just as I thought. File storage with computer/LED/Laser read/write on plastics is a STEP BACKWARD
in preserving records. Even the old phonograph
records and their vinyl replacement disks lasted for decades and were still intelligible.

The only thing that stood the test of time for
thousands of years has been stone engraved tablets
and metal engraved discs/plates.

We've been LIED to about the ADVANCES of technology and how much better we have it nowadays......everything is falling apart around
us..from energy and food production to communications media.

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