Life expectancy of external backup drives

imanidiot

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Forgive me if this isn't the right place to post this, but onward...
I use two identical WD My Book drives for TM and CCC. They are two and three years old respectively. Even if they continue to perform flawlessly, at what point should I consider replacing them just to be safe? I know that all HDD's fail eventually, but I'm wondering at what point I should replace a working drive for the sake of peace of mind? Know there is no hard and fast answer to this, but I just thought I'd ask for opinons.

Thanks.
 

cynics

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Jan 8, 2012
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At the first signs of a bad sector. Does the WD have any diagnostic tools?

You'd be much safer with a NAS running a mirroring RAID if you are concerned about HDD failures. Many NAS systems like from Synology, Qnap, etc will run a monthly scan and email you the results. If anything looks suspicious you can swap out that particular HDD and it will mirror the data back onto the new drive from the other drive(s).

Keep in mind when it does fail its relatively unlikely (although not impossible) your computers SSD/HDD will still be fine, giving you time to replace/fix the WD My Book.

Also a good idea just to throw this out there is to manually back up important information to an external and keep it off site (work, friends or family members house).
 

danielwsmithee

macrumors 65816
Mar 12, 2005
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Forgive me if this isn't the right place to post this, but onward...
I use two identical WD My Book drives for TM and CCC. They are two and three years old respectively. Even if they continue to perform flawlessly, at what point should I consider replacing them just to be safe? I know that all HDD's fail eventually, but I'm wondering at what point I should replace a working drive for the sake of peace of mind? Know there is no hard and fast answer to this, but I just thought I'd ask for opinons.

Thanks.
i wouldn't replace them. Just plan for an eventual failure and replace them when they do fail, or you need larger drives.

Most people don't realize the failure rate of brand new drives far exceeds the failure rate of drives that are a few years old. Most product failure rates follow that pattern.

It could be as much as 10 years before the probability of failure of a proven drive exceeds the probability of failure of a brand new drive.
 
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zaaach48

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Forgive me if this isn't the right place to post this, but onward...
I use two identical WD My Book drives for TM and CCC. They are two and three years old respectively. Even if they continue to perform flawlessly, at what point should I consider replacing them just to be safe? I know that all HDD's fail eventually, but I'm wondering at what point I should replace a working drive for the sake of peace of mind? Know there is no hard and fast answer to this, but I just thought I'd ask for opinons.

Thanks.
Tough question...I've seen drives fail anywhere from one month old to 10 years+

Most people will tell you around the time the warranty expires, but that has nothing to do with data safety. The hard drive could be only a few months old under warranty and fail, and you will still be just as screwed.

So there is no answer to your question. It's like asking "when do most people die?" well some die at birth, some live to be 110...but your average is around 70. So I'd say your average HDD lifespan is in the 3-5 year range.

The best thing you can do is just make multiple backups if the data is that important
 

Fishrrman

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Feb 20, 2009
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Drives are like people, in that they can expire unexpectedly and prematurely, and sometimes there's no way to predict when.

I've got old drives 10+ years old that still "spin up every time".
I've seen others die earlier.

For backup drives, I'd say "trust them" up to 5-6 years, SO LONG AS they keep operating well with no hints of problems.
Then, replace them (at least as "primary backups").

This doesn't mean you need to toss them out.
I'd "wipe them" and then continue to use them for "scratch storage" -- that is, non-critical stuff that you just want to keep around, but also keep from clogging up your "regular" drives.
In other words, stuff you can "afford to lose", but keep around anyway.
 

imanidiot

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Thanks for the suggestions everyone. Given that TM backs up to them alternately, my thinking has been that as long as they both don't fail simultaneously I should be able to avoid total catastrophe. If it were only one drive that TM was backing up to I'd feel a bit more vulnerable. I might go ahead and relpace the older of the two sooner than later just to hedge my bets.
I appreciate the input.
 

MacStu09

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Aug 27, 2009
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Everyone on here is giving pretty good information. You never know when it may fail, so just keep monitoring its health. I've had SSD's fail in a week, and others last years. HDD's fail in a week, and some last 8+ years now. But for any crucial files, I still perform backups to disc and store them safely. I've had way too many hdd/ssd failures to not do so. Not even RAID is always safe - I've seen entire lots of WD's die at almost the same time. (NewEgg reviews are great at helping to find drives with high early failure rates.)
 

imanidiot

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Everyone on here is giving pretty good information. You never know when it may fail, so just keep monitoring its health. I've had SSD's fail in a week, and others last years. HDD's fail in a week, and some last 8+ years now. But for any crucial files, I still perform backups to disc and store them safely. I've had way too many hdd/ssd failures to not do so. Not even RAID is always safe - I've seen entire lots of WD's die at almost the same time. (NewEgg reviews are great at helping to find drives with high early failure rates.)
Thanks for the tip about NewEgg.
 

nambuccaheadsau

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Run 'em until they drop.

Like asking how long is a piece of string. All drives, platter, SSD and Flash, will fail, some sooner, some very much later. They sometimes (Not frequently thank goodness) even come DOA in the box when brand new.

Best results for me have been WD and Fujitsu platters, OCZ (Toshiba) and OWC SSDs.
 

imanidiot

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Run 'em until they drop.

Like asking how long is a piece of string. All drives, platter, SSD and Flash, will fail, some sooner, some very much later. They sometimes (Not frequently thank goodness) even come DOA in the box when brand new.

Best results for me have been WD and Fujitsu platters, OCZ (Toshiba) and OWC SSDs.
Your advice feels intuitively correct. Thanks. I use WD drives simply because I have had good luck with them in the past.
 

imanidiot

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Quick follow-up question. When I run the WD diagnostics one of the drives (the older of the two) fails (that is, the WD diognostic software cannot complete its check). When I use the Disk Utility in MacOS, it finds nothing amiss. Should I be suspecious, do you think?
Hope I'm not being too stupid/tedious.
 

kwikdeth

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i think the case they are in will affect it a lot - HD case with no airflow, more heat, less life on the drive. i have an iomega firewire 800 enclosure i had to stop using because it was killing drives with heat - the case acted as a kind of heatsink for the fw chipset, and it kept getting almost burning hot to the touch
 

mlody

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I have two 2.5" hdds from mac mini server that have 17257 power on hours each. This converts to almost 720 days of non stop usage and both drives still run just fine.

As long as you make a backup of your primary backup, I would not be even concerned about prematurely replacing the drive. Keep using it until it either completely dies or when SMART starts reporting some issues with it.
 

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danielwsmithee

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I would not worry about WD or any other diagnostic tools as they are Windows tools as a rule.

Stick with DU.
While the WD tools are native to Mac OS. The first thing I do is wipe them from the drive and never install them. I agree stick with Disk Utility.

From my experience with external drives it is typically the cheap enclosure that dies or kills the drive before the actual drive fails.
 
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imanidiot

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I have two 2.5" hdds from mac mini server that have 17257 power on hours each. This converts to almost 720 days of non stop usage and both drives still run just fine.

As long as you make a backup of your primary backup, I would not be even concerned about prematurely replacing the drive. Keep using it until it either completely dies or when SMART starts reporting some issues with it.
Good advice. I'm inclined to feel that way myself.
[doublepost=1490787981][/doublepost]
While the WD tools are native to Mac OS. The first thing I do is wipe them from the drive and never install them. I agree stick with Disk Utility.

From my experience with external drives it is typically the cheap enclosure that dies or kills the drive before the actual drive fails.
I'll keep that in mind. Thank you.
[doublepost=1490788035][/doublepost]
I would not worry about WD or any other diagnostic tools as they are Windows tools as a rule.

Stick with DU.
Absolutely. I hear you.
 

windowpain

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I would also check out backblaze. The link earlier in the thread is to hard drive lifetime stats, but the service is very good.

I have a local back up like you (time machine and CCC) and also back up remotely with backblaze for about 4 bucks a month (I pay bi-annually so a bit of a discount.)
Just set it and forget it, and it gives me peace of mind. I am not too concerned with the other primary backups failing..ill buy new disks if and when they die.
 

imanidiot

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Would it be a good idea to uninstall the WD diagnostics software?
[doublepost=1490794715][/doublepost]
I would also check out backblaze. The link earlier in the thread is to hard drive lifetime stats, but the service is very good.

I have a local back up like you (time machine and CCC) and also back up remotely with backblaze for about 4 bucks a month (I pay bi-annually so a bit of a discount.)
Just set it and forget it, and it gives me peace of mind. I am not too concerned with the other primary backups failing..ill buy new disks if and when they die.
Thanks for the suggestion.
 

kschendel

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Dec 9, 2014
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It depends to some extent on your backup needs and your finances. Personally, I like to replace external backup drives about once a year to 18 months, whether they need it or not. I occasionally have to dig around in old archives for some file, and it would do me no good to have the old backup on a failed drive. (It's a good idea to hook them up every now and then, just to avoid any lubricant-freeze problems, if you're really careful.) External drives are cheap and I can afford to drop $50 or so every year, per machine.

If however your backups are really more about preventing immediate disaster, and you're not so concerned about old files, then I'd say what you are doing is exactly right. I would probably replace the older of the two drives now, and then replace either one when you get SMART issues or obvious failures.
 

Samuelsan2001

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They will last anything between 3&6 yeas on average but may of course fail at any time for any number of reasons like all electrinics.
 

kschendel

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One other note, if your external drives are on separate AC power, make sure they are plugged into a good surge suppressor or UPS. The same unit you have the computer plugged into should be OK. Don't plug them right into the wall unless you have whole-house surge suppression; using raw house AC is a good way to say bye-bye to both drives simultaneously if you get a spike.
 

imanidiot

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One other note, if your external drives are on separate AC power, make sure they are plugged into a good surge suppressor or UPS. The same unit you have the computer plugged into should be OK. Don't plug them right into the wall unless you have whole-house surge suppression; using raw house AC is a good way to say bye-bye to both drives simultaneously if you get a spike.
They are all plugged into a UPS, plus I have whole-house surge suppression. But good point.
 

HDFan

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Jun 30, 2007
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I use two identical WD My Book drives for TM and CCC
Assuming we're talking about a backup strategy here, the golden rule is to have 3 backups on 3 different types of media (disk, tape, maybe internet) in 3 different locations. I would replace one of the working WD drives with a totally different drive from another vendor (see backblaze report). Take the good but replaced WD and put it in off-site storage. This way you are actively backing up to two drives from different vendors with two different life expectancies. You don't run the minuscule risk of both drives failing at the same time at the end of their life.

I did a totally unreliable calculation of how many backblaze drives failed a day from the last 90 day report. Looks as if they have about 4 drives a day fail and they are not particularly worried about it. In other words plan for failure so when it happens you don't sweat it.


As above run 'em till they fail. Since you are alternating backups between two drives it's not a problem if one dies.
 
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MacStu09

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Aug 27, 2009
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Quick follow-up question. When I run the WD diagnostics one of the drives (the older of the two) fails (that is, the WD diognostic software cannot complete its check). When I use the Disk Utility in MacOS, it finds nothing amiss. Should I be suspecious, do you think?
Hope I'm not being too stupid/tedious.
From experience, I would NOT rely solely on Disk Utility. I can't count how many times I've had failing drives, but DU found nothing wrong until it simply didn't recognize the disk at all anymore.
 
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