I get variations of this question all the time. I also get questions about backing up in general where folks are backing up to DVDs.
This is also one of those questions where the answer has changed over time. What was once a reasonable and common practice is now something that at best is impractical, and at worst a disaster waiting to happen.
The short answer: heck no! You should not back up to DVDs.
The longer answer has several reasons behind it.
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The math against backing up to DVDs is pretty simple.
My Windows 8.1 Surface Pro, for example, has 80 gigabytes of data on it. Even if compressed by 50% (also something that varies greatly based on how the computer is used – it’s rarely greater than that, though), that’s 40 gigabytes of data that would take 9 DVDs to back up completely.
And of course the more your system holds the worse it gets.
One of the things that comes up from time to time is the lifespan of writable DVD media. The bottom line is that it may not be as long as you think.
Now, it might be that a daily or periodic backup to DVD doesn’t really need to last that long, and that’s fine. But if you’re taking backups that you might need to refer to in a few years, then DVDs are once again not a great choice. They might last, but they might not be readable when you need them. (And with 9 DVDs for that backup of mine, it would take only one of them to fail to invalidate the entire backup.)
Yes, there are archival-quality DVDs, and they may very well last longer on average, but when you then factor in the quantity you need the costs can start to ramp up as well.
With that backup of mine taking 9 DVDs – and others taking perhaps more – the convenience factor, or rather the inconvenience factor becomes significant in two ways:
- Do you really want to sit at your computer and swap out DVDs for however long your backup takes?
- In order for you to back up, you must manually swap out DVDs for however long your backup takes.
The net result is that if you back up to DVDs, swapping discs alone becomes a huge disincentive to back up at all. And that’s never good.
We want backups to be painless and easy, and automatic if at all possible.
Not something you dread.
There are scenarios where backups to DVD (or even CD) might be an appropriate backup medium.
- Backing up a subset of your data that fits on a small number of discs. This would presumably be in addition to a more complete full backup performed some other way.
- Backing up files in a manner that’s easy to exchange with others. While this can be done with backup software and other media, there’s nothing quite a simple as just dragging and dropping files from one place to another, and handing someone a disc.
But those are not really backups. At best, they are a supplement to a more rigorous backup process.
They are not a substitute to be completely relied on.
Get an external hard drive.
Get one that’s at least twice as big as the data you want to back up. If practical go for five or 10 times as big. Have a hard disk containing 100 gigabytes? Get a 1 terabyte drive. You can never have too much disk space.
Then, configure your backup software to backup automatically to that external device.
No discs, no swapping, not even any remembering on your part.
Backups just happen.
And you’ll quickly find that the up-front cost of an external hard drive is actually cheaper than all those DVDs you’ve been buying.