Helping people with computers... one answer at a time.

How can you protect your data long term from media degradation to loss and theft? We'll look at hard drives and a variety of media types and discuss revisiting your storage periodically.

I currently have images stored on memory cards, thumb drives, CDs, and DVDs. Which is best long term?

In this excerpt from Answercast #51, I look at the variety of storage media available and speculate about where it will head in the future.

Best storage media?

Unfortunately, you'll get a lot of conflicting answers to that, so I'm actually not going to give you a specific recommendation. I will give you some general terms though.

Optical media

First of all, when it comes to optical media like CDs and DVDs, quality matters. Quality matters a lot, as a matter of fact.

Archival quality CDs and DVDs are probably worth the money if you're thinking of storing these for many, many years.

Flash memory

I don't have a lot of faith in memory cards and thumb drives.

Flash memory? It should work... Theoretically, it should last for a really long time. But just because, again, there is such a variation in quality in manufacture when these things are created, it's just not something I really would put a lot of stock in.

I know that many people do use them, and do use them successfully. But whether or not they're going to be readable 10 years from now, for example, I really can't say.

External hard drives

What I use myself for long-term storage is, of all things, external hard drives.

Hard drives by and large have probably the best long-term storage; if they're stored properly. In other words, you're not storing them around big magnetic fields. Don't stack them behind your big sub woofer speakers or something like that.

In general, they're a good place for a lot of data. In fact, most people can put a lot of data on a single external hard drive and then squirrel it away somewhere.

Future compatibility

I know that a lot of people are concerned about things like compatibility. Will our computers 10 years from now or 20 years from now be able to read the media that we write things to today?

We actually have that problem right now:

  • People who have stored things on, for example floppy disks, 20 years ago are now encountering the fact that their computers don't have floppy drives anymore;

  • And they have to take some special steps.

I'm fairly confident that the USB interface, and USB external drives, are going to be supported for a fairly long time. I would certainly give USB2 another good 10 to 20 years worth of acceptability - in terms of being a way to connect to computers that we might be using 20 years from now.

Try to keep up

That being said, it's also one of those things that's worth revisiting every few years.

I know that one of the things that I do periodically is I migrate my older backups from their old media (in my case, for example, CDs that perhaps I burned 15 years ago) and move them on to hard drives, which themselves then are backed up.

And I will state that, "If you have only one copy of something, it's not backed up"

What I really recommend people do when they're looking at storing things long-term, keeping the backups long-term, is to make sure you have two copies. That's another way to protect you from everything from media degradation to loss and theft.


The other advice that people generally give is don't put all your eggs in one basket. In other words, use DVDs and hard drives - so that you are actually splitting the risk of which one may not be useful 20 years from now.

So those are some guidelines. I'm sorry I can't give you a specific answer to this. It is something that I do encourage people to revisit periodically just to make sure that the important things you saved 10 or 15 years ago are still accessible to you today and 15 or 20 years in the future.

Next from Answercast 51- Why does scripting not work in FireFox?

Article C5787 - September 8, 2012 « »

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?


sahil waste
September 9, 2012 7:48 AM

wow!! Leo...thanks for the awesome advise, i only backup my data on dvds but from now i am going to follow your advise and going to backup everything twice and on two diffrent medias. thanks

Bill H Sr McMullen
September 11, 2012 1:07 PM

"Best Long Term Storage Media"
If you are recommending the pursuit of/for high quality (Archival) DVD media, you might want to mention Mellenium Disc (M-Disc) media. While the blank media are single layer and not inexpensive, it has NO dye layer; no disintegration over time. Also, the burner drives manufactured by LG retail for aprox $80 USD.
You can find LG brand combo BluRay burner and M-Disc burner, internal. I also have an LG brand external M-Disc burner.

September 11, 2012 9:31 PM

I have a LOT of floppies with good stuff on them that I spent over a week transfering (all data that was usable) onto DVD's. I'm glad that's over. I'm watching and waiting for the next generation of storage media and wondering what it will be like.

Robert R
September 12, 2012 2:12 PM

There was a study done at NIST some years ago on CD quality and archival properties. Leo is right in that there is a big difference in the quality of CD/DVDs. And price is not always a good indicator (but cheap is...).

Fred Christman
September 13, 2012 10:21 AM

20 years????? In twenty years we will have chips implanted and simply think our internet searches or messages. Who knows what 'backup' will mean. Probably nothing you can put your hands on. I shouldn't say WE. I'm an old man who's been a professional in computers since they reached the street. I will not participate in that future.

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