Storage: Is there a life expectancy on external hard drives?

by Lee Koo (ADMIN)

- 5/29/09 1:02 PM

Total posts: 137

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Post 46 of 137

MediaFire

by mitragyna - 5/29/09 10:00 PM In reply to: Persistenc of data only gets cheaper by whmurray

Another great website for backup is http://www.mediafire.com . This site also keeps your data for as long as they last.

Free music downloads: http://toweroffunk.blogspot.com/

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Post 47 of 137

Life expectancy on hard drives

by Watzman - 5/22/09 7:58 PM In reply to: Is there a life expectancy on external hard drives? by Lee Koo (ADMIN)

Is there a life expectancy on hard drives? Yes, there is, but I can't tell you what it is (it varies). It is not based on calendar time but on "power on hours", at least usually. It's fairly long (the numbers I have seen have ranged from 50,000 to as much as 300,000; note that if the drive was left on 24x7x365, a full year is a bit over 8,000 hours). Also, drives have a system in them called "S.M.A.R.T.", which is "self monitoring and reporting technology" or something like that, generally, in so far as "natural" death is concerned (not death caused by a sudden event like a physical shock), the drive will usually know when it's going to fail and is capable of giving warning IF ASKED. The problems with this are that SMART does not always work unless the drive is connected natively (directly via IDE or SATA; not by USB or Firewire) and many systems are not setup to "ask" the drive about it's health (for drives connected natively, most BIOS' have an option to do this each time the system boots; amazingly, the default, however, is often to disable this capability). In particular, drives connected by USB or Firewire (in other words most external drives) probably never get asked.

ON THE BRIGHT SIDE: I'd probably rather trust your "old faithful" drives, even if they are 5 years old, than a brand new drive that I had just received from a vendor. The death rate for drives in the first 30 days (some would say in the 1st 6 months) is frighteningly high.

Last comment: An external drive should be a backup, not a primary drive. And, further, you should always have multiple copies of anything that is important. If these rules are followed, it would be difficult to lose data due to the loss of a single drive (and, in particular, a single external drive). You should have another copy somewhere.

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Post 48 of 137

life of external hard drive

by maggiedev - 5/29/09 10:20 PM In reply to: Life expectancy on hard drives by Watzman

i am good on a computer, but have absolutely no knowledge of the technical side. when my old windows xp finally gave up the ghost, my grandson took the hard drive out, reformatted it and put it in a case. that is my external hard drive. i put my massive amounts of photography on disks and then on the external hard drive. i keep in a cool place and never touch it except to download or retrieve photos. i have had it for several years now and when this computer gives up the ghost, i will do the same with it. works for me.

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Post 49 of 137

Life Expectancy

by Hforman - 5/22/09 8:01 PM In reply to: Is there a life expectancy on external hard drives? by Lee Koo (ADMIN)

Ted, we recently had a discussion on CD and DVD media and the life expectancy predictions were all over the map depending on who read what. Without getting into firm numbers, I've seen hard drives last a few months to lasting many years.

There are advantages to using a hard drive for backup but, first, what do you mean by "backup"? There is a difference between backup and archive. In the case of backup, the primary copy of the data will exist elsewhere. That means you will always have a minimum of TWO copies of the data. In the case of an archive, there may only be one copy on archive media.

One of the issues with backing up to disk is the finite space on the disk. Someone once said that if the backup drive is the same size as the main disk drive, it can always be used as a backup. This may not necessarily be true if you plan on keeping multiple generations (current backup + one that is a month old + one that is 3 months old + one a year old). The more generations you plan to keep, the more space will be taken up. You need to analyze your data to determine how many generations of that data would be kept. Say you are keeping backups of data that changes daily and a loss of 1 week would be unacceptable. Then there would not be much point keeping anything older than a week old as the data would be worthless. Keep in mind, this may not really be the case when you can restore two weeks back and then go through physical papers to recreate the missing data. If you figured out that only ONE copy of all of your data is all that is really needed, then you have very little to worry about because the odds of losing both the original data and the backup is small. However, if you will need to have access to a lot of older generations of the data, making several backups may be a good idea if they are all on seperate media as any media can suffer sudden death brought about by non-disk related things such as temperature problems (fan dies?), processor problem, fire, theft, etc.

If you really want to know what the manufacturer thinks is the lifetime of the disk, look for a statistic on the manufacturer's description of the drive called "Mean Time Before Failure" or "MTBF". There are different measuring units for this but it should give you an idea of how to compare drives. This, of course, assumes that the disk manufacturers all thoroughly tested their drives to come up with this number and there is some conformity in the testing. Still, this is a "mean time". Your mileage may vary (for better or worse).

You don't need to "retire" your drive arbitrarily. Many times a drive will give you a warning before they go such as data errors in some file or by the use of S.M.A.R.T. technology. You can alwas "push" the issue by running diagnostic tests (non-destructive) on the drive and see if small errors popup. I would not recommend this, though, because the tests could damage the drive more than you would expect.

Here are some alternatives to think about:

1) Periodically, burn your data to a DVD. Especially if you use archive grade, these backups could last awhile even though your current backup is still on the disk. If you don't use archive grade, the MTBF is about 5 years and some people reported having degradation after only three.

2) Consider a RAID system for your main data drive and/or the backup drive. If you don't know much about RAID DISK, it can easily be looked up. I would recommend something fast, like, RAID 1 for your primary data drive and a slower RAID 5 or 6 on your backup drives.

3) If there will be a "gap" between your last backup date and your current date for your data, consider keeping some paper copies for the short term (Quicken can print transaction reports, for example).

4) If any drive or fan starts to make unusual noises, that is the time for immediate repair or replacement. Waiting a few weeks is not a good option.

So, to answer your question directly, the MTBF statistic could be used as a guide but remember that a drive can fail at any time and this stat is only a mean/average figure. The best way to handle this is by planning what data needs to be backed up, how often the data changes and ask youself "If the drive (backup or main) dies in 5 minutes, how much trouble would you be in?" Use redundancy for critical data and consider environmental changes as a cause of problems almost more than just the drive "wearing out".

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Post 50 of 137

Do external hard drives have a life expectancy?

by StephanBer - 5/22/09 8:02 PM In reply to: Is there a life expectancy on external hard drives? by Lee Koo (ADMIN)

Do external hard drives have a life expectancy? ABSOLUTELY. Inside each external enclosure is your standard computer hard drive, either a 2.5" laptop drive in your portable external hard drives or a 3.5" desktop hard drive inside the larger, less portable external hard drives.

Each drive has an electrical motor in it that actually spins the platters within the hard drive. As it's your standard electrically based magnet and coil motor, there's friction in effect, which means wear and tear, which means eventually, that motor will fail. It's not "if" it fails it's "when" it fails.

This is the most common way hard drives fail, but if you've ever seen the bottom of a hard drive, you'll see hundreds of different parts, circuits, resistors and other various electronics that are all just waiting to fail. Eventually.

Some manufacture's will even TELL you how long your hard drive will last. If you can figure out what it all means.

Here's one from a popular hard drive manufacturer's data sheet.

Reliability/Data Integrity
Contact Start-Stops 50,000
Annualized Failure Rate 0.34%
Mean Time Between Failures (hours) 750,000

But before you start counting how often you turn it on, or how long you've been running it each day, or crossing your fingers and just hoping it doesn't fail today, do what makes sense.

if you have content that is highly important to you, either personally or professionally, then treat it as such. Do two kinds of backups. One optically (CD's or DVD's) and one magnetically, IE: with an external hard drive. Or use an online backup service. or use 'flash' memory, such as a USB thumb drive or a very new (and still quite expensive) SSD (Solid State Drive) since you'll very likely be dead before the drive fails. Or so they say... Just as optical discs were supposed to last a lifetime, we now see that they don't.

Personally, I just buy a new external hard drive every year. They get bigger and cheaper every year, and I typically am near to running out of space every year ANYWAY, so moving into a bigger drive actually makes quite a bit of sense in a couple of ways. I'll then copy everything over to the new drive, then 'archive' the old drive (put it in a box in the closet up high enough away from my 9 year old) and just use the new one. That way if my current model fails, I still have most of what was important to me. Better 'Most' than 'None'.

If you're really really REALLY worried about your data, keep your archived external in a small fire and water resistant box and put it in your safe deposit box at the bank.

The nice thing about using online backup services is that they also do 'redundant' backups, so it's much more likely it'll always be there. The only downside to using an online service is that the initial upload is well, slow. Kinda like watching paint dry. In the rain. While watching the movie The Titanic for the third time. While listening to your mother-in-law go on and on about her last vacation. All while you're getting a root canal. It seemingly takes forever, and you're still left wondering if they got it all.

I expect there are too many variable to make a life time projection for your external hard drive. However, the reliability of most all electronics is inversely related to operating temperature. Let it get too hot and it is sure to fail far more quickly than under normal operating temperature conditions.

Hopefully your external drive is in an enclosure that sucks away the heat from the drive, and the enclosure temperature reflects the temperature of the drive itself. If you external hard drive is getting hotter than just merely warm to the touch, you are risking an early failure. If necessary, take a surplus 12 volt CPU fan from an obsolete computer; connect it to a surplus 5 volt dc cell telephone power supply, and use it to keep the external drive cool.

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