March 29, 2012

Installing OS 10.6.8 on a Mac Mini built for 10.7 – yes, it’s possible.

Installing OSX on a i5 Mini using Target Disk Mode

Installing OSX on a i5 Mini using Target Disk Mode

Man, do I hate OSX v10.7, aka “Lion.” Like, I really, *really* hate it. In a production environment, you don’t need a version of your everyday OS acting all hinkie… but that’s what Lion has been doing since I was forced into using it on a new Mac Mini I got about a month ago for dev.

After numerous attempts to wipe & install 10.6.8 (nice, stable, friendly, reliable ol’ 10.6.8) using an external DVD drive, I was coming up dry. No luck, so it’s time to get creative.

Luckily, there’s a way to get rid of that nasty “not ready for primetime” OS as long as you’re not scared of getting your hands dirty. Here’s the methodology I used, based on this thread over on the Apple discussion boards… you’ll need the following:

• a new Mac Mini (referred to here as Mac #1) running OS 10.7 with either an i5 or i7 processor.

• another Mac (either MBP or iMac is fine, referred to here as Mac #2), as long as it’s fairly recent and has an installed i5 or i7 processor.

• the original OS 10.6 install discs that Mac #2 came with (those are the grey ones).

• a FULL RETAIL INSTALL version of OS 10.6 (that’s the one with the Snow Leopard on the cover)

• a FireWire 800 cable

The process…

1. Grab your Mini, and go to System Preferences » Startup Disk. Tell it you want to boot it into Target Disk Mode.

2. Hook up the FW800 cable between the Mini and your i5 Mac (for me, I used my 2.4 i5 MBP), and restart the Mini in Target mode. The Mini should pop up on your Mac’s desktop as an external disk.

Now, here’s where you get creative…

3. Launch Disk Utilities, nav to the Mini, and erase the entire disc. Personally, I always do a “zero out data” and (depending on time & existing data) possibly a low level format.

4. After the format & erase is done, pop the RETAIL version of the 10.6 installer disc into Mac #2, and hit “Install.” Tell it you want to do a new install of the OS on that Mini (that’s Mac #1) sitting on your desktop. Your Mac #2 will quit every open app and go into an install mode – this is okay. It needs to do this to install 10.6 on Mac #1.

5. IMPORTANT STEP: about 20-30 minutes into the install, Mac #2 will try and restart. HOLD DOWN YOUR OPTION KEY AT THIS POINT. Your Mac will be at a grey screen here, showing you available discs for booting. Here’s where you eject the retail version of 10.6, and pop in the 10.6 install disc that Mac #2 came with. Once that newly inserted 10.6 disc shows up, highlight the disc and choose it as your boot volume.

6. The install will pick up where it left off, installing all the i5 or i7 proprietary drivers along with the remaining 10.6 pieces. When the install is done, Mac #2 will want to reboot. Again, this is a good thing.

7. After reboot, the Mac will restart using Mac #1 (that’s the Mini) as the primary drive. Yeah, you might be *using* Mac #2, but you’re booted to the Mini so it’s all good. Run thru the registration process, then run all OS updates until you are running a full clean version of 10.6.8.

8. Select “Shut Down.” This will shut down Mac #2, but Mac #1 is still on and in Target mode. Push & hold the power button until the Mini shuts off completely.

9. Unhook the FW800 cable. You’re done.

10. Power up both Macs. Mac #2 is just as you left it, and Mac #1 is running a rock solid version of 10.6.8.

Let me know how your install goes in the comments!


  1. John

    Another reason that Apple products boarder on the ridiculous. The fact that you can’t downgrade MAC OS without creating a Rube Goldberg-type setup is just dumb.

  2. Gregg Tomlinson

    It’s strictly a hardware issue, based on the introduction of the i5 & i7 processors AFTER initial release of 10.6. The retail version of 10.6 (which was released in ’09) does not contain the drivers for those particular processors, that’s the only issue.

  3. Phil

    Once you have gone through this process can you clone the mini’s HD to an external one using something like Carbon Copy Cloner and then hold this in case you ever need to install a clean system?

    FWIW I agree with you re 10.7 but also I’d add that I don’t want to upgrade every piece of software I use. I’m very happy with Adobe CS5 and I don’t want to spend many $s so that I have to re-learn the applications in that suite. Apple should have maintained a 10.6 line for new hardware for pro use and inflicted 10.7 on home users who usually have much less invested in software.

  4. Steve

    Gregg, Which version Mac Mini’s does this work with? All of the one’s recently running Lion, or just selected ones – any idea?

  5. Gregg Tomlinson

    @Steve I’m using this method with an i5 Mac Mini, dual core with one 2.5GHz processor. Under About This Mac » More Info, it’s model identifier is Macmini5,2.

  6. Gregg Tomlinson

    @Phil – Totally agree, 10.6 is rock-solid stable, so no reason to rock the boat, right? As for CCC, you read my mind – that’s the first thing I do when I get a system running stable – clone it in it’s pristine state to an external so I can fall back on it in a dire emergency. For day to day backups on my dev servers, I use Time Machine – works really well.

  7. MacPaul

    And what happens when you just clone a working 10.6.8 to the HD of the new Mac Mini? Does it boot or does it really need a clean install because of the drivers? If not, it could be possible to run 10.7 on the all new Mac Minis, because 10.8 is even worse as 10.7 and therefore one might be happy to have 10.7 instead of 10.8.

  8. @MacPaul – the Mini needs the drivers that get installed during the clean install unfortunately, so there’s no super clean way of doing a clone.

  9. Dan

    Hi Gregg,

    Great post. One question: Does this work on the 2012 macmini that come with ML? I’m guess it does as we’re talking about getting SL to install and use the i7 drivers. Am I right? Thanks.

  10. Dan

    Further info: I have a MBP which has TB (but no USB3) which came with Lion but is running SL now. I also have 09 Macmini which is now running SL. I also have SL Retail disc. And all the machine specific grey DVD install discs for the two various macs. Hope to hear what you think. Thanks. (I plan to buy a 2012 Macmini and have it run SL. yes I hate Lion and ML too)

  11. I believe it does – I am using this on a 2012 MacMini that came with Snow Leopard, and reverse-engineered it to use 10.6 with this methodology.

  12. Brian

    Hi Gregg, I need SL to run Logic, I like your workaround but it does not work for me, yet. I have 2 new mini servers and an old mini 1.5 ghz single core running 10.4.11. The old mini accepts the disks without issue and is the driver of the server HD in Target Mode. After the second disk boots and runs the installation I get an info box telling me the OS can’t be installed on this system. After the install I can access the mini server from the older mini 1.5 and it runs SL through Target Mode but when I drop Target Mode and restart the server It will not progress beyond the grey screen with apple logo. Shucks. I have run a few variations, from the SL drive on the server through Target Mode, but same result. I have tried 2 other iMac’s running Lion and ML, the retail disk is inoperable in those OS’s. I think I’m stumped. Any suggestions?

  13. It’s got to be the Mini running 10.4 that’s the kink in the armor here. You can’t run 10.4 on an Intel mac so I don’t think that Mini is running an Intel single core, I would suspect it’s PPC.

  14. Kristy Wilke

    what if mac #2 is a core duo

  15. Kristy – not sure if you’re going to have that type of problem with a core duo Mac, this is pretty specific to i5 and i7 Macs built for 10.7 and up, and the core duos were all built for 10.6 or lower.

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