Can I do my backups over the internet?

The problem you'll run into is bandwidth.

Unless you have an incredible internet connection, the copy off-site will take longer than the backup period. In the table below I've done a little back-of-the-envelope math, and as you can see, a 120 gigabyte backup will take over a week to upload at "traditional" T-1 or good DSL speeds. If you have a VERY good internet connection - beyond the maximum of DSL rates, you're still talking a day to upload and that's assuming perfect communications and 100% use of the internet connection.

In my opinion across-internet types of backups really only make sense if:

• you have an extremely fast internet connection

• or the amount of data that you're backing up can somehow be constrained to a more reasonable amount.

In other words, across-internet backups just don't make sense for full backups, and they rarely make sense in incremental backups in an busy environment.

So what about those online backup services?

First, I'm sure that they're doing everything as smart as they possibly can to minimize the impact of bandwidth limits. I'm sure they compress whatever they can, and that they copy only things that have changed, and that they use your internet connection at what would otherwise be "idle" times - which for many people is most of the time.

However, that doesn't change the fact that a full backup is a heck of a lot of data; much more than one would want to upload via any typical internet connection.

So compromises must be made, and it's those compromises that concern me.

The most typical compromise is to use an internet backup service to backup only your data. This makes total sense, and is a great compromise, as long as one huge issue is addressed. In fact, I do something very similar myself on a semi-regular basis.

That one huge issue? How do you backup the rest of your system?

It's an issue that's very common when you choose to backup only your data, regardless of the reason. The issue is simply this: what happens when you lose something that isn't part of what you backed up? An installed application, perhaps, or even Windows itself? Your on-line data-only backup will not help.

That's why I recommend on-line backups only as part of a larger backup strategy that includes full backups to more traditional backup media.

To put it even more concretely, here's what I do:

• Every night important data is collected on one central machine. The other machines are not backed up in any other way. This implies that if something worst-case happens to them I will end up having to rebuild them from scratch. Based on what they do and how they are used, this is an explicit choice I've thought through.

• That central machine is actually my primary desktop machine. Full backups are performed on it monthly, and incremental backups are taken nightly. I use Acronis True Image Home and back up to an external USB hard drive.

• Also nightly, some particularly critical data is copied across the internet to the computers at my wife's business, and vice versa. Because of the bandwidth issues this is a limited amount of data; something that can be copied in just a few hours in the middle of the night. (And the primary computer there is also doing monthly full and nightly incremental backups using Acronis to an external hard drive.)

• Once a month a larger collection of data is assembled, compressed and encrypted, and uploaded to an off-site server. This is about 2.5 gigabytes of data, and takes several hours to upload.

As you can see, remote backup can be a part, but only a part, of a larger backup strategy. I strongly recommend off-site backup of some sort, and it's one approach to that. However, that doesn't remove the need to do an explicit and well-thought out backup of full systems and data.