The New York Times published an article today about making off-site (a.k.a online) backups that contained some debatable advice.
The point I most disagree with is this: "As long as your credit card keeps working, there's no need to think about the backups unless disaster strikes." The problem with this advice is that if something is automated too much, it can break without your knowing it.
The classic example of this was the magazine Business 2.0 (which has since ceased publication). After they deployed an automated backup system, they ignored it. At some point the backup system broke, but no one noticed. Only when their main computer system failed and they needed the backups did they learn that the backup system had stopped working long before.
Do you leave your house and simply close the door, confident that it locks behind you? What if something jams the latch? What if that button that prevents the lock from engaging was pushed in? Isn't it worth taking the extra few seconds to try to open the door after closing it just to ensure that it's really locked?
It's the same with automated backups. If your files are important, it's worth a little time to ensure that the backups are actually being made. Then too, you should test recovering a file or two, just to be sure that you still can. It's the computer equivalent of a fire drill.
The article also said, "The idea is simple. The user installs some software..." Installing software is not necessary for making off-site backups. It may not even be a good approach.
For one thing, installing any software is risky. Backup software that needs to know every time a file is modified has to both run all the time and be intimately wedded to the operating system. Both raise the level of risk.
The requirement to use software from the backup storage company may also limit the computers from which you can make backups or perform restores. Some backup companies charge by the number of computers being backed up, and they use their software to enforce this. Even if you choose a company that charges solely by the gigabyte, if they offer Windows software and you later buy a Mac or a Linux-based Netbook, you may not be able to back up files from your new computer.
Some backup services offer a Web page front end. If you know your user ID and password you can walk up to any Internet-connected computer in the world and either upload or download files from the backup service. There's a lot to be said for that. I just purchased a Netbook computer and used such a service for making my initial backups. No software needed.
Then too, some backup services can be used with portable software. In the Windows world, the term "portable" refers to software than can be run without being installed. Typically, portable software is thought of in terms of running the software from a USB flash drive, but the software can also run from the C disk. I personally use the free, portable WinSCP program offered at PortableApps.com with a paid backup service.
WebDAV is yet another option for accessing off-site backups without installing software. WebDAV is a protocol that, in Windows, lets you view remote files much like Windows Explorer lets you view local files. WebDAV support is available in all current operating systems.
In Windows XP, WebDAV is a "Network place." The procedure to add a remote network place is simple, all you need to know is the name of the remote computer, and a user ID/password. An existing network place can be made into a desktop icon, providing simple, easy access to remote files.
Anyone serious about off-site backups needs to consider where, physically, their remote files reside.
The article touched on this and reported that Intronis stores files in Toronto and New Jersey, iBackup stores customer files at two of the company's four centers in California, and iDrive uses only one data center.
Off-site backups are best stored as far away from you as possible. Another time zone is a good rule of thumb.
If your off-site backups are your only backups (not advisable but better than nothing), then you should only consider a company that keeps redundant copies of your files in multiple locations. Here too, the farther apart the better.
Amazon's S3 service stores files in multiple data centers in the U.S. For an extra fee, you can also have your files stored in Europe. When you sign up with rsync.net, you get to choose whether you want your files stored in San Diego, Denver, or Zurich, Switzerland. Here too, for an extra fee they will store your files in two locations.
In brief, you need to be aware that if you accidentally delete a file from your computer, Mozy will delete their backup of that file. Such is the nature of a service that offers unlimited storage space for a fixed price. Any such provider is motivated to minimize the amount of data they store.
Another optimization they use is to copy only the portions of your files that have changed, rather than the entire file. This is complicated, and I think simple is best, especially when it comes to backups.