Take Control of Mac OS X Backups: The Online Appendixes

In Take Control of Mac OS X Backups, I emphasize two main types of backups. One is the bootable duplicate, in which the backup software makes an identical copy of your entire startup disk and stores it on another hard drive in such a way that you can start your Mac from your backup drive if your main disk fails. The other is the versioned backup, in which the backup software copies some or all of your files to another location (such as a hard disk, network server, or DVD) and then, on subsequent runs, adds to your backup only new or changed files—but without deleting or overwriting what was previously copied. Because I think these two elements are the cornerstones of a solid backup strategy, I’ve divided the applications and services shown here into two groups: those that have either or both of these features (the top portion of the table), and those that have neither (at the bottom).

In this table, I also indicate whether a program is compatible with Leopard and/or Snow Leopard and whether it’s available on any other platforms as well. Here, as in the other tables on this site, click a column heading for more information about the feature being described.

Enterprise-grade backup software is not shown here.

Last updated: February 7, 2010

Feature Explanations for This Table

Bootable Duplicates: If the software can create an exact copy of your entire startup disk such that you can use the copy to boot your Mac, it gets a “Yes” in the Bootable Duplicates column. Note, however, that not all such programs are created equal. For example, those marked with footnote [a] can perform the unusual feat of making a bootable backup on a drive connected to another Mac on your network. Also see the Metadata Support column on the Other Features page, as faithful copying of metadata is important for a good duplication program.

Versioned Backups: A versioned backup starts with a complete copy of all the files in one or more folders. The next time the backup runs, your backup software could make another complete copy, but because most of the files probably have not changed in the meantime, that would use up a great deal of space—and also take a long time. So backup programs typically perform an incremental update. This means that on subsequent runs, the software scans the folders you’ve designated and copies only those files that are new (or newly modified) since the last backup. By definition, versioned backups must be additive, meaning the backup program adds the new or changed data to the backup without overwriting the files already there. That way, you can retrieve many different versions of a given file, and if you delete it on your hard disk, you can still find it in your backup.

Leopard and/or Snow Leopard Compatible: With only a few exceptions, the software shown here is fully compatible with Mac OS X 10.5 Leopard, running on either an Intel-based or PowerPC-based Mac. A few programs, however, have not been (and will not be) updated for Leopard. Similarly, most either have Snow Leopard-compatible versions or will soon be updated to work on Snow Leopard. A “?” in this column simply means the developer hasn’t stated whether the software runs on Snow Leopard. In any case, if the software in question won’t run on your version of Mac OS X, it’s not worth considering.

Available for Other Platforms: A number of Mac backup programs also come in versions for Linux and/or Windows. This might be a good thing or a bad thing, depending on the program. If you need to back up several computers running different operating systems, you may appreciate the convenience and familiarity of a single tool that works on all of them. Usually, though not always, if you create versioned backups with a multi-platform program, you can open and restore your files from another platform than the one you used to back them up. On the other hand, a few of the cross-platform programs have truly hideous user interfaces that were either written in Java without any consideration for the Mac aesthetic, or very badly ported from another operating system.