How far back Time Machine archives can migrate to new versions

What happens if you have a Time Machine backup of an old version of OS X, and you want to transfer the data to a new Mac?

time machine el cap icon

Eric Desrochers happily runs Mac OS X 10.6 Snow Leopard—and that’s a version that a lot of people remained delighted with for a long while, particularly the 10.6.8 final release.

If I was to upgrade to a newer, or even the newest OS, will the new OS be able to use the Snow Leopard era Time Machine backup to restore my things on the updated OS? Or am I doing backups more or less for nothing?

Time Machine backups can be used to do a full system restore of a dead hard drive or computer, but also migrate just user files, applications, and some settings from one computer to another. You can do this during system setup of a new Mac, after installing a fresh copy of OS X on a computer, or even using Migration Assistant while OS X is up and running and you’re logged in.

I haven’t had to migrate files via Time Machine for over a year, and it’s a little bit of a complicated situation, but not a horrible one. Apple’s support documents should guide you, but they’re a little confusing if you’re running quite old versions of OS X.

The last supported version of OS X that can update to 10.11 El Capitan is 10.6.8, according to Apple’s documents. You should be able to upgrade to any system running 10.9 Mavericks or 10.10 Yosemite, too. (Apple also provides instructions for migrating from systems as old as 10.4 Tiger: a migration works from Tiger to systems as late as 10.7 Lion, while 10.5 Leopard can be migrated to at least Mountain Lion.)

If you have a migration problem with an older system that can run a newer version of OS X, but not as new as you want, it may make sense to go through the tedious exercise of upgrading the Mac to the latest OS it can handle and then applying all the updates not included in the OS update. Create a fresh Time Machine backup from that updated machine or use Migration Assistant for a direct Mac-to-Mac transfer, and you should have better luck.

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