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A recently released report from Google has some disturbing information.

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This is Leo Notenboom for

Several weeks ago Google released a paper detailing an analysis of the consumer-grade hard drives they use in their data centers. As you can imagine, Google has a lot of hard drives.

They were looking at what could be learned from hard disk failure rates.

One surprising result was that they determined that hard disks Self Monitoring, Analysis and Reporting Technology, or "SMART" as it's known, could not be used to accurately predict when or if a drive was about to fail. Drives reporting SMART errors often lasted for years, while other drives were just as likely to fail without any SMART diagnostic information prior to the failure.

Much more importantly, though, are what I think are some very scary numbers about hard drive failure rates. For example, for drives older than 2 years, Google reports seeing about a 7% failure rate per year. Put another way, one out of every 14 drives will fail within a year.

That's way higher than I would have predicted.

It also makes me very nervous.

Disk drives are cheap, but the cost of replacing one can be enormous. For example, unless you're doing true full backups a sudden failure means you're going to have to reinstall and reconfigure your operating system and all the applications you had on a failed drive. If you've been backing up your data you may not experience data loss but you'll definitely lose a chunk of time for the rebuild.

And if you haven't even been backing up your data - well, you've got a serious problem.

There are several possible approaches to minimizing the risk of a hard drive failure, but for the average consumer nothing, and I mean nothing can replace a good full backup strategy.

In fact, after hearing these new statistics, it's a change I made myself. In the past I'd been backing up my important data, of course, but not my operating system and applications. As of earlier this week I now do a nightly backup of the entire hard disk on my primary computer using Acronis Trueimage Home.

Regular listeners and readers of Ask Leo! will know that I've always stressed the importance of backing up. Google's latest report only makes me even more convinced that disaster prevention isn't just a good thing, it's a requirement.

Check out the show notes for links to Google's whitepaper and to a similar study performed at Carnegie Mellon University with similar results. I've also linked to an episode of the highly recommended Security Now podcast with Steve Gibson and Leo Laporte which covers this issue as well.

I'd love to hear what you think. Visit and enter 11293 in the go to article number box to access the show notes and to leave me a comment. While you're there, browse over 1,000 technical questions and answers on the site.

Till next time, I'm Leo Notenboom, for


Article C2973 - March 24, 2007 « »

Leo Leo A. Notenboom has been playing with computers since he was required to take a programming class in 1976. An 18 year career as a programmer at Microsoft soon followed. After "retiring" in 2001, Leo started Ask Leo! in 2003 as a place for answers to common computer and technical questions. More about Leo.

Not what you needed?

Louis Benn
March 26, 2007 3:58 AM

7%? That is Much higher than we have, we've been lucky i guess.
1 failure in 3 years. :)

Gerald Malcolm
March 30, 2007 7:09 PM

7%-- I have had # failures in the last ywar. one only lasted 4 months--i back up full all the time.

Michael Horowitz
March 30, 2007 9:03 PM

Acronis True Image can make image backups either from within Windows or outside Windows running from a bootable CD. I would only trust an image backup made from outside Windows, but that's me. The entire True Image v8 manual however was geared to backups from within Windows.

Recently I tried to make True Image backups from a boot CD on a machine without a PS/2 port. Despite being Linux, both v7 and v8 failed to detect the USB keyboard.

But my biggest gripe with True Image is that it can not make a true image. That is, it is incapable of doing the basic job of an imaging product, make a sector by sector copy. For details see

March 30, 2007 11:39 PM

I think Google probably runs their hard discs pretty hard that way they get a better ROI. I doubt any of us are running HDs 24/7. From a HDs point of view you could easily think of 2 years work at Google being the equivalent of 5 years in a home or office environment.

Ann E. Hynes
March 31, 2007 8:09 PM

I just listened to the podcast on hard drive failure. Expensive, yes,to the tune of about $465. I wish I had known this sooner. Thank you for your newsletter. I'll keep reading!

Ken Crook
March 31, 2007 10:51 PM

Bought a new HP Pavilion notebook and the hard disk died after only 5 months of use. HP shipped me a new one, but I wasted 3 days rebuilding everything. I now, as Leo, use Acronis TrueImage to backup my hard disk so next time my disk crashes or is trashed I'll save those wasted 3 days.

Vicki Williams
December 29, 2007 4:42 AM

I've had one failure in the 15-20 years that I have owned a computer. That drive did fail during its first year.

berny marsden
January 19, 2009 10:04 AM

I teach computer maintenance, & I always stress that the reason for making backups is NOT "in case your hard drive fails" because I can guarantee that one day it WILL fail & that day could be as soon as the day after you bought the pc. If you change your mindset to "backup for WHEN it fails" you are much more likely to do regular backups. Incidentally, I can recommend DriveImage XML for "hot" system drive backups. I used to use PowerQuest DriveImage (no connection) but it was always breaking after MS system updates. The XML version has been rock solid.

Darius Dinshah
January 22, 2009 12:38 PM

All the comments refer to stopping an external drive. There was a reference to the internal drive always spinning when the PC is running. Not so. In the "Power" pull-down you can set the internal to shut down after any number of minutes or never if you wish. Much data being entered appears to go to another place, either RAM or maybe a cache. When needed, the indicator LED shows the internal being reactivated, and then writes to it. It may not save much elec, but would it not extend bearing life?

February 8, 2009 1:50 PM

S.M.A.R.T technology uses threshold values to estimate the health status of a hard disk. The estimation of a failing date is like a trend estimation on how attribute value will change based on past values, it's just a statistical algorithm.

July 8, 2009 2:21 AM

If the HDD is continually spooling up and down, its mechanical components will be worn out faster. My last HDD lasted 10 years and is still working.

Robin Clay
July 14, 2009 12:14 PM

1. The world population is divided into two categories of people - those who have had a hard drive crash, and those who haven't - yet.

2. There is a theory that it is actually kinder to the hard drive to keep it running, so that it never gets cold - most wear occurs on cold start-up. No, I turn mine off....

3. "Full" back-up is all very well, but.... what I really REALLY want is to be able to do an incremental back-up, i.e. only back up those files that have changed. AND what *I* would like is for the program actually to re-name files that already exist on the back-up drive by adding the time-stamp, so that they are not overwritten.... NOT a lot to ask, but it's "not out there"- well, I haven't found it yet....

4. No, I'm not interested in backing-up the "pagefile.sys" file, etc. (not that one can under Windows, anyway), but presumably a "full image" backup would include them ? If not, it ain't a "full image"....

July 15, 2009 1:40 PM

I've got a whole pile of sub GB disks, in the 80MB - 800MB range, disks that will most likely still be running when all of my 250GB & up disks are dead.

there's something to be said about the older slower speed drives!

March 21, 2010 3:33 PM

To the 1,2,3,4 "Robin Clay" person above, you are missing quite a few very important details about backing-up your work. You're not interested in drive-image backups? There is no other way to avoid spending two weeks rebuilding an entire configuration from scratch. Professional drive-image backup software will exclude large pagefile.sys type occurrences as an option. Windows does not "need" pagefile.sys to recover. Check out TERABYTE UNLIMITED on the web, their product also provides an incremental drive-image option but full drive images are what protect against loss of months/years of configuration time.

Glenn P.
March 23, 2010 1:49 PM

Ah, Terabyte! Thanks for mentioning that, GL -- that's what I use: BootItNG! Works like the proverbial charm!           :)

March 23, 2010 1:51 PM

I guess you have to take into consideration the make and model of the hard drive.
I have had 100% reliability with Maxtor (now Seagate) and Western Digital (10+ years on those 4).
I've had 0% reliability with 2 Samsung drives (both died within a year) and a pre-Maxtor Seagate (it died in about 6 months).

Don Beal
March 24, 2010 5:35 PM

I have a Panasonic CF-W2 "Toughbook" that I had to install an additional 512 RAM into just to get it to perform reasonably.
I admit it was a couple of years old and I bought it used.
I have replaced the Hard drive twice (professionals did it)but it crashed again less than a year later.
Now no one locally wants to tackle putting in a new hard drive and no one seems to know if it may not be the Motherboard.
Panasonic will "look at it for $57.00 if I ship it to them but it is probably good money after bad.
This thing never did what it was supposed to and I think it cost somebody
@ $3800 NEW!

March 28, 2010 1:23 AM

Yes, that hard drive will fail. But I don't bother backing up my OS. I use Fedora Core, and update the entire OS with every release of FC, about every six months. I keep all my non-OS data on an external drive, and back that up daily. My OS is running on a 30GB drive. I have no need for a huge internal drive.

Dean Simes
March 31, 2010 8:15 PM

Re doing a nightly backup of the entire hard disk - I am puzzled as why this is better than monthly image and daily incremental, which I understood was your previos practice. I had thought that the OS would not change during the month (except for the interim updates) and that there may be some new applications, but that incremental updating would catch all of these. Apparently I am missing something here - but I am very much a learner.

My nightly backup is incremental, and I do a monthly full.

June 8, 2010 3:08 AM

Thanks for reminding me to always backup my files.With hard drives.They can crash any time and thus data can be lost.With me i opted for an online backup called safecopy online backup.I store all the backups in need with safecopy because of the efficient services they offer.

July 28, 2010 7:28 AM

Used Acronis True Image Home 2010 on W7 though seemed to require a backup USB drive of the same size to work bcronis propriety does not like Linux so would not clone the Fedora small boot partition and took many hours to clone the rest. So bought and installed Farstone Total Recovery Pro. This exactly clones all BUT 23hrs to do a !TB.

Alexander Walsh
January 24, 2013 8:26 AM

Just a word of warning for those interested in installing a secure backup system. For several years I depended on a relatively expensive program and hard drive provided by Rebit. When one of three hard drives in RAID 0 array failed the backups were useless. As best I can determine, when the drive failed the backup system overwrote the files on the backup drive with the corrupted files from the failed drive. A professional who salvaged most of my data from the failed drive was not able to salvage anything from the Rebit drive.

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