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Roy Miller Author

Level 1

31 points

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

Hi all,

the following instructions were provided to me by our Apple Enterprise tech, and I've successfully performed these steps on a newly purchased MacBook Pro.

Please note the following - as of 15 Aug 2011:

- this technique will work on new MacBook Pro, Mac Pro or iMac computers UNTIL Apple modifies the hardware in these computers

- this technique will NEVER work on currently shipping MacBook Air or Mac Mini computers

- this configuration of Snow Leopard installed on a computer that shipped with Lion is not supported by Apple Support. It is entirely possible that after a trip for an AppleCare support incident, or the Apple Genius Bar, that the computer will return with Lion installed.

with these caveats, here are the step-by-step instructions:

---------------------------------------------------------------------

HowTo - NetRestore - Install Mac OS X 10.6.8 on new Mac delivered with Mac OS X 10.7.0

note: this only applies to Macbook Pro, Mac Pro, and iMac computers that originally shipped with Mac OS X 10.6.x.

Current Macbook Air and Mac Mini computers cannot be downgraded.

Required resources:

- another computer, running Mac OS X 10.6.8

- spare external disk

- Snow Leopard installation disc (Mac OS X 10.6.0 or 10.6.3 Box Set)

- Snow Leopard 10.6.8 Combo image file (download from Apple Support Downloads page)

- System Image Utility 10.6.8 (download Mac OS X 10.6.8 Update Combo v1.1.dmg from Apple Support Downloads page)

Procedure:

A. Create the NetImage:

1) mount the base source image (Mac OS X 10.6.3.dmg - created from Box Set Installer)

2) launch System Image Utility (from Server Admin Tools)

3) when source (from mounted image) appears in SIU screen, click Custom button

4) drag "Customize Package Selection" from Automator Library window to location

between existing "Define Image Source" and "Create Image"

5) drag "Add Packages and Post-Install Scripts" from Automator Library to location

between "Customize Package Selection" and "Create Image"

6) in the "Customize Package Selection" section:

a) expand the "Mac OS X" triangle

b) select options desired

c) collapse the "Mac OS X" triangle

7) mount the appropriate update image (Mac OS X 10.6.8 v1.1 Combo.dmg)

8) copy the MacOSXUpdCombo10.6.8.pkg package to a new local directory (Desktop/parts/)

9) drag the MacOSXUpdCombo10.6.8.pkg icon from local directory to the

"Add Packages and Post-Install Scripts" section of the SIU window

10) in the "Create Image" section:

a) select the type "NetRestore"

b) set the "Installed Volume:" field to "Macintosh HD" (no quotes, can be any name)

c) select the "Save To:" location

(will be faster to a second local internal disk)

(not faster to another partition on the same disk)

d) set the "Image Name:" field to "Snow Leopard 10.6.8 NetRestore"

e) the fields "Network Disk:", "Description:", and "Image Index:" don't

matter unless one is going to use results on a NetBoot Server

11) click the Run button

12) when the dialogs appear, ignore the text and click OK for proper completion

Dialog text: "Image creation in progress.

Cancel the image creation to proceed"

B. Post-process to create Restore Image:

1) find the directory created in the above process, named as in A.10d above

(Snow Leopard 10.6.8 NetRestore.nbi)

2) in this directory are three files:

- i386

- NBImageInfo.plist

- NetInstall.dmg

3) mount the NetInstall image (double-click the NetInstall.dmg file)

4) navigate into the Contents of the package, to: System/Installation/Packages/

5) copy the System.dmg file out to desktop or other work location

6) rename System.dmg to meaningful name, such as "Snow Leopard 10.6.8 System.dmg"

7) copy this .dmg file to external, bootable, Snow Leopard 10.6.8 system disk (install in /Users/Shared/)

C. Install Snow Leopard 10.6.8 on new MacBook Pro or Mac Pro

via command line:

1) boot MacBook Pro or Mac Pro from external source prepared in B.7

2) open Terminal

3) find the restore target device specification

a) run the command "diskutil list"

b) look for a 650 MB partition, labelled "Recovery HD" (likely disk0s3)

c) the target partition should be immediately prior to the "Recovery HD" partition

d) for a new computer with a 500 GB drive, this partition should be

labelled "Macintosh HD", with a size of 499.2 GB

e) make note of it's Device Identifier, likely disk0s2

4) issue the following asr (Apple Software Restore) command

sudo asr restore --source "/path/to/restore.dmg" --target /dev/disk0s2 --erase

(replace "/path/to/restore.dmg" with the path to the location and name used in step b.7)

5) this process proceeds and completes quickly, about 3-5 minutes. This is due to

the "--erase" parameter; it indicates a block-copy operation

If the process seems slow, likely the "--erase" option was omitted and

the copy is being done as a file-copy operation. Quit (ctl-c) and

examine the command used...

via DiskUtility GUI:

1) boot MacBook Pro or Mac Pro from external source prepared in B.7

2) launch /Applications/Utilities/DiskUtility.app

3) select the computer hard drive (typically "Macintosh HD")

4) click on the "Restore" tab

5) click on the "Image..." button to specify the "Source"

6) navigate to /Users/Shared/ and select the "Snow Leopard 10.6.8 System.dmg" file

7) drag the computer hard drive volume (Macintosh HD) to the "Destination" field

(note: grab the volume, not the disk!!)

8) enable the "Erase destination" checkbox

9) click the "Restore" button

10) in the ensuing "Are you sure?" dialog, click the "Erase" button

11) authenticate with the local admin credentials

Apple Tech recommends leaving the Restore partition alone, and installing in the "Macintosh HD" partition only

commands to know:

- asr

- diskutil (diskutil -list to see partitions)

- hdiutil

Posted on Aug 15, 2011 9:00 AM

364 replies

Roy Miller Author

Level 1

31 points

Apr 23, 2014 1:55 PM in response to fab_am

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

fab_am

Level 1

0 points

Apr 29, 2014 3:07 PM in response to Roy Miller

> 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?

this is the hardware overview of my MBP:

Model Name: MacBook Pro

Model Identifier: MacBookPro9,1

Processor Name: Intel Core i7

Processor Speed: 2.3 GHz

Number of Processors: 1

Total Number of Cores: 4

L2 Cache (per Core): 256 KB

L3 Cache: 6 MB

Memory: 4 GB

Boot ROM Version: MBP91.00D3.B08

SMC Version (system): 2.1f173

*** according to everymac.com:

Pre-Installed MacOS: X 10.7.3 (11D2097)

> 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.

*** in fact, I was looking for some solution including drivers for new hardware, taken from the 10.7 installers!

[snip]

> 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....

Beware of Mavericks!!! I did the upgrade from the installed 10.7, but the experience has been terrible. I'm using the mac from the honorable MacPlus: I've never, never seen the arrow cursor lagging wrt the mouse! this is frequently happening on Mavericks (and on Mountain Lion too, btw)! It is unbelievable, you see the daring spinning disc while the four (four!) cores are all idle! what generation of programmers has Apple hired recently? people that plainly ignore anything lives under APIs?

[snip]

> cheers, and good luck,

> Roy

I begin to believe I'll need a lot of it, thanks! By now, I'll probably go to buy one of the last mac able to run SL.

Thank you a lot for your fast response,

fab

Nov 6, 2015 3:12 PM in response to fab_am

Hi Fab_am,

I love Snow Leopard as well (last great Apple OS X).

The simplest way to do this is to create a universal 10.6.8 disk image (take any old Mac which will install Snow Leopard: you can buy a Mac Mini which can do this for $100 these days or borrow one) on a compatible computer.

Then use SuperDuper to clone that minimal image (it's about 6 GB) to the hard drive of the install computer (better yet, use a USB adapter like those which come with Samsung SSD's to do the clone from the original computer) and then install that ready drive in the target computer.

For laptops, you can use target disk mode.

It's really quite easy.

Dec 16, 2015 6:26 PM in response to Roy Miller

Ah, TimeMachine. Another Time Bomb from Apple that's caused me nothing but grief. What the **** happened after Snow Leopard? Every iteration has been a dog (mountain or Landmark) with new new traps and disasters in every version.

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