HowTo revert new MacBook Pro, Mac Pro or iMac to Snow Leopard

Hi beloved,

you need to have an external disk, with Snow Leopard 10.6.8 already installed on it, that can boot the computer with Lion on it.

then, and only then, do you copy the .dmg file you've created to it.

you can not copy the .dmg file to a plain USB stick and boot from it.

The .dmg file is not a bootable image. It is a restorable image. This means it is a source image which Disk Utility can use to restore a bootable system to the destination computer.

I hope this helps!

I'll take a moment to reiterate one of the caveats of installing Snow Leopard 10.6.8 on any current Mac model. Snow Leopard does not contain drivers for all the hardware in any Mac that has new hardware installed after August 2011. As you can see in the recent tcmcbride67 post, the current trackpad on Mac laptops is new, and there are no drivers in the old operating system to support it!

I figured this thread would die a graceful death before the end of 2011. Although I understand well a desire to run Snow Leopard on current Mac models, I for one am moving forward with learning, understanding and configuring Lion to do what I want and/or need. With Mountain Lion not far away, running Snow Leopard on new hardware is becoming less and less possible, regardless of whether one "likes" the Lion OSes or not.

my best wishes to all who want to try - and make a good, restorable backup of your Lion system prior to attempting a Snow Leopard install!

cheers!

Hi fab_am,

well, you found the correct place for a procedure that works - for the appropriate hardware!

first - how old, or really, how new, is your MacBook Pro?

if it is not the version that was produced in the summer of 2011, that had originally shipped with Snow Leopard (10.6.x), and then the same hardware shipped with Lion (10.7.x), then there are likely to be issues. As stated early in this thread, newer hardware may, and usually does, contain components for which no drivers exist in the Snow Leopard series of Mac OS X. This is because the hardware was developed/utilized after Lion was released, and development of Snow Leopard stopped.

if the drivers for your specific hardware components are not included in the OS you install, functionality will suffer, as those components will not work correctly, if at all.

If your MacBook Pro was delivered with Snow Leopard installed originally, then you can revert with little or no difficulty. Just pull out the optical disks the computer was shipped with, and *after* backing up your current disk, you can reformat the internal drive, install the Snow Leopard OS, and begin to rebuild your account(s).

note - since you've been running in Mountain Lion, some of the applications you may have been using will have updated the format of their files, and are likely no longer readable by older versions of the app. In particular, Mail.app has changed aspects of how it stores its files, and I suspect the Snow Leopard version of Mail.app would not be able to read the format to which your mail files have been converted when you installed Lion and/or Mountain Lion.

my recommendation, at this date, is to do the free upgrade to Mavericks (10.9.x), and learn to work with it. I'm currently in the process of upgrading all our Snow Leopard systems, that I've been using since Snow Leopard was realeased, to Mavericks. I've jumped over the Lion series....

sure, some of my favorite helper apps no longer work, and Rosetta is a thing of the past, etc. However, the world of computing moves on, with or without us. Sooner or later we have to move on as well, or deal with an increasing inability to utilize current technologies. You may be sure that when you eventually buy a new laptop, it will not be able to run Snow Leopard - or old versions of Windows either, if you go that route.

fab_am wrote:

please, if you have found a way to install Snow Leopard can you share it with me? thank you in advance, fab

the procedure presented in this thread IS a way to install Snow Leopard on a MacBook Pro of a certain vintage, so you have already found the answer. If you decide to proceed with this procedure, in addition to the requirements stated in the procedure, I urge you to buy an external disk, download Carbon Copy Cloner or SuperDuper, make a clone of your current system before you do anything else. Then, if things get screwed up in applying this procedure, you can use those apps to clone the external system you created back to you MacBook Pro, and you will not have lost your working system. Relying on a Time Machine backup will NOT give you the same flexability and security....

cheers, and good luck,

Roy

You should be pretty good from here... follow the steps... sometimes you have to mount images before restoring them but Roy didn't say and I don't remember if I did that... so stick with the plan, don't panic, one way will work, and it will restore a pristine 10.6.8 build to your waiting iMac.

I'm pretty sure that I did not mount the image prior to copying.

as I recall, from the Disk Utility Restore pane, the image file (System.dmg or whatever one renames it to) is accessed via an open dialog. The open dialog appears when one clicks on the "Browse..." button. So I believe that Disk Utility is able to access the image files, without having to mount it.

@zirkenz - when you get to this part C, you've already done all the hard work, and the block copy of the image system to you new computer goes fast - like 5-10 minutes!

Hey Photonomadic,

you just caught me about to log off!!

the new Mac Pro's you bought 2 days ago came with Lion installed, correct?

if so, there are absolutely no pre-existing Snow Leopard discs that will boot these machines, outside of those which you might be able to convince Apple to send you. They were the discs that the same Mac Pro's shipped with immediately prior to Lion's release.

So,

a) there is no problem with installing another internal hard drive to use a Snow Leopard boot drive.

b) short of the above-mentioned rare discs, there is no other way (of which I'm aware) to get a "proper" Snow Leopard system installed on a 2-day old Mac Pro delivered with Lion than following this procedure.

Of course, you can use whatever filenames you want for the System.dmg file, and use a different directory/folder besides /Users/Shared from which to deploy the system image, but basically the steps must be followed to achieve the desired result of installing a "proper" Snow Leopard system on a Mac Pro delivered with Lion installed.

more in a bit...

Trying to get Roy to click over our way and share share share! Awaiting a working virtualization solution, but we'll take anything good we can get!

aargh - I'm really good at wiping out my post edits!

anyway Steve, the Mac Mini issue (and MacBook Air issue) revolves around this: these models, with their current hardware configuration, never, ever, shipped with Snow Leopard, according to my Apple Enterprise Tech. Therefore, there is no version of Snow Leopard that can fully support them. I did post early on in at least one Mac Mini thread, with basically this info.

Of course, if, for example, the only hardware change were related to Bluetooth components, and the end user never used or disabled Bluetooth, then it is possible that Snow Leopard 10.6.8 v1.1 would run one of these computers well. But I think it is very dangerous to expand this specific set of circumstances to a general solution.

I was also informed that Apple will not be compiling a new version of Snow Leopard (10.6.9?) to support these hardware changes. "Never have and never will" - these are the words used.

so, eventually, we'll all be running Lion on our newer hardware, unless there are some very creative non-Apple solutions to doing so.

I've been looking at the Tech Specs on Apple's Support pages at current and recent models. The first category are not good candidates for Snow Leopard, the second set used to run under Snow Leopard (= good candidate)

Never shipped with Snow Leopard:

• Mac Mini Mid 2011, release 21 July

• MacBook Air Mid 2011, release 21 July

Shipped with Snow Leopard originally, now shipping with Lion:

• MacBook Pro Early 2011, release 25 February

• Mac Pro Mid 2010, release 16 August 2010

@Zirkenz - I notice two "recent" releases for the iMac. One falls into each category. I wonder if this is some of the issue for your model. Which one is your 'new' iMac?

• iMac Late 2011, released 8 Aug

(never shipped with Snow Leopard, I believe)

• iMac Mid 2011, released 3 May

(certainly shipped with Snow Leopard)

(and may have shipped with Lion installed)

Okay, so Server Admin Tools 10.7 does not let you create a netinstall image-option is grayed out....

hey Zirkenz - the end result of this procedure is a NetRestore image. So I think you are still golden to go.

please try selecting the NetRestore Image option, and proceed as before.

If I wrote to select the NetInstall Image as the only option, then I should have elaborated. In SIU 10.6.8, it apparently doesn't matter whether one chooses NetInstall Image or NetRestore Image - this option can be chosen later on, so long as one choses "Customize" in the SIU interface, as best I remember. In the dialog that shows the flow-chart of processes, there is a section near the bottom for output file attributes, such as filetype, etc. In this section, one can select the type of the final output file. It should be a NetRestore Image file, regardless of where one sets that preference.

okay, found it: Step A.10.a

cheers!

Hi RPG2288,

...what gives? you can put windows xp on a new computer...you could choose not to upgrade from leopard or snow leopard on a mac...you can install an old linux on pc/mac....what about complex Mac applications....they're not written (or optimized) for lion....forced upgrading?

yes, and then you have to install drivers to support the hardware that was built after the version of Windows XP was compiled.... Same is true for Linux......

and in a way, the same is true for Mac OS X....

so, computers that have hardware embedded in them that was not in models prior to the release of Lion (10.7.x) cannot be fully supported by Snow Leopard (10.6.x), as that version of the OS has no driver support for that new hardware. This is pretty much common sense if you think about it in the terms of: "It is impossible to build in support for hardware that doesn't exist yet".

I suppose if the new hardware is something that you personally don't use on your computer, you could get away with installing a previous version of the OS and things might work well. For example, if it were to be the Bluetooth interface that was the new hardware, and you never use Bluetooth and turn it off, everything might work well. I believe this is the case for reports of some people having some levels of success installing Snow Leopard on the new Mac Mini (not so much that Bluetooth is the new hardware, just the concept...)

add to this that Apple has never, and I mean historically never, added support for new hardware to old versions of the OS, and you arrive at the situation we have today. The current Mac Mini and MacBook Air have had new hardware installed, that did not exist in these models during the time of Snow Leopard being the "current" OS. Until new hardware is installed in shipping models of Mac Pro, MacBook Pro, and iMac, the possibility to install Snow Leopard version 10.6.8 on these models exists.

However, these models will not boot on Snow Leopard 10.6.0 or 10.6.3 discs. Why? same reason as above - the current hardware configurations did not exist when these versions of the OS were compiled. Therefore this simple complicated (neat, eh?) procedure evolved.

hope this helps,

Roy

HI kagepeint,

glad you got it working - I was sure by now that this "short-term" procedure would die a graceful (or not so) death by the end of calendar year 2011!

I believe your difficulty with step 7 was that you were trying to copy the 10.6.8 installer dmg file to a bootable installer disk, rather than a bootable installed disk. The procedure is to have/create/clone an installed system on an external disk. That disk, like any computer with Mac OS X 10.x.x installed, would have the standard directory structure that we work in every day, including the "/Users/" directory, which contains your home directory(s), and one labeled "Share".

If I remember properly, the procedure continues to then boot the new computer from this bootable external disk, and launch the 10.6.8 installer, from which you install Mac OS X 10.6.8 onto the 2011 computer that came with Lion installed.

There are many ways to acheive the install - the key is to be able to boot the Lion-delivered computer from an external drive containing the 10.6.8 installer, and run that installer to populate the computer's internal disk. One could even clone the 10.7.x system to an external disk, and use that to boot the computer and install the 10.6.8 system....

To any who read this far in the thread, it is my humble opion that it is now already past time to be porting oneself to Mac OS X 10.8.x, and move on with the Apple OS, for as long as they continue to produce computers and OS X. I know of many of the reasons for not doing so..., no lectures necessary! ;-)

cheers,

Roy