Downgrading Mac OSX Lion to Snow Leopard

Thursday, July 28th 2011. | Software News

We like Apple OS X Lion a lot (you can read all about it in our OS X Lion review), but that doesn’t change the fact that a new OS always carries its growing pains. For some Office and Adobe users, those growing pains may be growing migraines. And if you have a NAS, forget about it. So let’s say you want to put Apple’s new feline up for adoption and return to Snow Leopard: how much trouble is. Depending upon your Mac—and your back ups—not much at all.

If You Back up
If you have a backup of your Mac pre-Lion, rolling back the clock is surprisingly easy. For Time Machine users, Lion’s Recovery HD includes an option to restore from an existing backup. Meanwhile, more tech-savvy Mac users may have cloned their drives using something like Carbon Copy Cloner. In this case, also, Lion’s Recovery HD enables you to image your drive from an existing backup using Disk Utility.

Back to the Disk
For the less backup prone, the process will require your original Snow Leopard disk. Lost it? Apple still sells it for $29. Before you get started, you’ll want to back up your data (if you haven’t already). The simplest way is to copy your User folder(s) (Macintosh HD/Users) to an external disk. Unless you have data scattered across the hard drive, this ought to preserve your music, photos, videos, and documents.

From here, insert the Snow Leopard disk. It’s not worth trying to run the installer. (I received the rather creative error message: “You can’t install this version of the application Install Mac OS X with this version of Ma OS X. You have Install Mac OS X 23.1”). Furthermore, when I tried to boot off the disk the old-fashioned way (holding the “C” key at startup) I received kernel panics. Instead the easiest way is to boot into Recovery HD by holding down the command and “R” keys at startup. Once you’ve reached the recovery screen, Open “Disk Utility” under “Utilities” on the menu bar. The first thing you’ll need to do is reformat your hard disk. In Disk Utility, open the “Erase” tab. Select “Mac OS Extended (Journaled)”—it ought to be, by default—and click “Erase.” It should only take a moment, and once it’s finished, your Mac’s hard drive will be as clean as the day Steve Jobs envisioned it.

Next, navigate to the “Restore” tab. From the left-hand sidebar, drag and drop “Mac OS X Install DVD” into the “Source” field, your hard drive into the “Destination” field, and click “Restore.” Quit Disk Utility and reboot your Mac when you’re finished.

From here, you’re in familiar territory. Copy over your user folder from that backup, and, as always, run Software Update for all the latest Apple patches and updates. For example, in the time that you switched to Lion, Apple released another supplemental update to Snow Leopard that ought to ease any hiccups with audio or networked printers.

Caveats for MacBook Air owners
For diskless-Mac owners, the fact that previous directions necessitated a Snow Leopard DVD could be a bit disheartening. If you’re running the previous version of the MacBook Airs, however, don’t fret: as long as you have another computer—Mac or PC—with a disk drive, you can borrow that machine’s optical drive to reinstall Snow Leopard. Apple also sells an external disk drive for $79.

New MacBook Air or Mac Mini owners have no downgrade path, however. Snow Leopard lacks the necessary drivers for Apple’s latest hardware. To test, I tried to reimage our new 11-inch MacBook Air with Snow Leopard by connecting it with a Thunderbolt cable as a target disk to a drive-equipped iMac. About a third of the way through the installation process, the iMac experienced a kernel panic disabled the iMac and the MacBook Air would not boot until I restored it to Lion.

Downgrading is possible
In closing, as long as you’re willing to reformat your Mac’s hard drive and start fresh, reverting to Apple OS X Snow Leopard isn’t a daunting process. It’s particularly simple if you’re diligent about backing up—especially if you use Time Machine—and, even if you aren’t, manually backing up and restoring is manageable if you an external hard drive.

Unlike Lion, Snow Leopard reinstallation is disk-centric. If you don’t have one, you’ll need one. For previous MacBook Air owners, this may be an extra impediment, and for the latest adopters of the Air and Mini, you and Lion are in it for the long haul. And that might not be a bad thing: Despite its youth, Lion is a mature OS from Apple and many of the growing pains users are reporting are just that—growing pains. If you can stick it out, stick with it. Otherwise, consider this your exit strategy.

Related For Downgrading Mac OSX Lion to Snow Leopard