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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

Aug 22, 2011 5:48 PM in response to Roy Miller

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

How do you do that?

If i have the mac box set with 10.6.3 can i erase the HD and install SL that way?

Karina_T

Level 1

0 points

Aug 23, 2011 2:19 AM in response to Roy Miller

Hi Roy,

Yes, I also kind of worked it out that 10.6.8 would be the only version that would work on my new mac.

I'm back into the Applestore today where they'll look at it but I realise now I'll just have to go with 6.8 and use the new beta for PT9 and thankfully, there's an M-Audio driver for 10.6.8 now for my interface.

Not quite ideal but at least a workable compromise in the meantime.

Thanks for taking an interest in my plight!

Roy Miller Author

Level 1

31 points

Aug 23, 2011 7:58 AM in response to Shezan Hirani

Hi Shezan,

I highly recommend that you carefully read all the posts here.

If i have the mac box set with 10.6.3 can i erase the HD and install SL that way?

the answer to this is in my post immediately preceeding yours....

the new Macs only run under OS X 10.6.8, 10.7.0, or 10.7.1......

based on the description of your situation, which for some reason is not displayed in this thread, but was on the email I received from your post,

Shezan Hirani wrote:

I'm kinda in a bind, i bought a mid 2011 imac from a 3rd party reseller who insisted the sytem had SL prior to purchase but when it arrived it has lion. My old imac is a g4 20" with tiger and i just found out that i cant migrate my emails to lion. I can from SL. So going back to SL is critical for me. Before SL came out an Apple genius said if i bought the mac box set i could revert any future system, Lion for sure, so i bought a family pack thinking i'd wait for the new systems and then downgrade those and then after lion i was told that was not possible. If i had know i would have ordered my imac before hand.

I would recommend the following path:

- upgrade your G4 iMac to Snow Leopard 10.6.3, using the box set

- this should then upgrade your Mail database to an appropriate level for migrating to Lion

- remain on Lion with your new iMac, and migrate your account(s) from the old iMac using the migration assistant

if you really feel that you need to "downgrade" the new iMac to Snow Leopard 10.6.8 (the only Snow Leopard option), please make sure that you have the necessary resources, as described in earlier posts. To do this, you will need to have access to a computer running Snow Leopard 10.6.8, so you may have to upgrade your G4 iMac in any case.

here are the resources necessary (from my initial post, with the SIU reference corrected):

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

(Mac OS X 10.6.8 Update Combo v1.1)

(download from Apple Support Downloads page)

- System Image Utility 10.6.8

(Server Admin Tools 10.6.8)

(download from Apple Support Downloads page)

if you do proceed, please print out the initial post, and read and follow the directions carefully.

Good luck!! 😀

Aug 25, 2011 6:21 AM in response to Roy Miller

Roy,

Thanks for the very helpful post. But I do have one question. How do I get the "base source image "Mac OS X 10.6.3.dmg' " from the box set start up disc. When I use disc utility I get a disc image for the whole dic entitled "Mac OS X Install DVD.dmg" This was created using the Snow leopard 10.6.3 box set installer. Is this the correct image?

Thanks,

Mark

Roy Miller Author

Level 1

31 points

Aug 25, 2011 7:11 AM in response to Mark Caltech

Hey Mark,

you basically got it correct.

the procedure I used was to have the Disk Utility create a disc image from the Install DVD, as you have done.

Indeed, you are correct that the resulting image is named: "Mac OS X Install DVD.dmg". The procedure will work from this point forward, as written, with the exception of my error in the download filename for the last required resource (should be Server Admin Tools 10.6.8.dmg). I've erroneously listed the name of the SL Combo 10.6.8 v1.1 file as the source of the System Image Utility.

anyway you may proceed with the base source image named however you want. The step that I used, that is not explicitly documented is to rename the "Mac OS X Install DVD.dmg" file to "Mac OS X 10.6.3.dmg". I've done this so that I can tell immediately from the filename which version of the OS is to be installed using this image.

also, I've collected a variety of such installer images, and keep them in the same directory. Aside from my purpose above, each image file requires a unique name within my set.

cheers!

jsd2

Level 5

6,245 points

Aug 25, 2011 7:43 AM in response to Roy Miller

Roy Miller wrote:

I would recommend the following path:

- upgrade your G4 iMac to Snow Leopard 10.6.3, using the box set

A G4 (ppc) can't run Snow Leopard.

Roy Miller Author

Level 1

31 points

Aug 25, 2011 7:50 AM in response to jsd2

jsd2 wrote:

Roy Miller wrote:

I would recommend the following path:

- upgrade your G4 iMac to Snow Leopard 10.6.3, using the box set

A G4 (ppc) can't run Snow Leopard.

duh! of course! yet another brain-glitch 😉

Aug 25, 2011 11:36 AM in response to Roy Miller

Hi Roy!

Woaaah... that's really awesome - thank you so much for sharing your precious knowledge. After reading your post the couple of first times things seemed to be rather confusing for me - but the key was to give it a try - and many questions disappeared by looking at the GUI of the System Image Utility (from Server Admin Tools).

May I add some hopefully helpful hints?

I found out the the nag-screen "Image creation in progress. Cancel the image creation to proceed" does *NOT* appear when you (immediately prior to step A.11 in your tutorial!) try to quit the System Image Utility. Then you will be asked if you want to save your settings - please do so and save your settings under s meaningful name like "hope_it_works" or so. This will be creating a file with the hidden extension ".workflow".

Next quit System Image Utility, use the Finder to go to the place where you just stored your workflow file and double-click it:

This wil open an Automator-window which looks slightly different from the System Image Utility.

In the upper right corner of the menu bar you will find a "PLAY" icon (like on a CD-player) probably labeled "execute" or "run" (my OS language is German...) click it and you're done after waiting for not too long!

I tried this twice with different settings (even succeeded to integrate the iLife'11 package into the compilation) and did not see the nag-screen mentioned above again! 😎

If one plans to go through this procedure several times it might be a good idea to use the "DiskUtility" to create an image files from DVDs or CDs you have to use which can be mounted when you need it.This will eliminate the noise from the optical drive during your compilation - and under "Add Packages and Post-Install Scripts" you have the chance to add packages from multiple DVDs (i.e. from their mounted images) even if you have only one optical drive!

In conclusion: Your post is by far the very best what I've been reading about this topic ever!

Thanks again,

Oliver

P.S. The only thing I need in addition right now is my brand new 13" MBP - DeliveryStatus says it will arrive in 4 days - I will let you know if everything works fine!

Roy Miller Author

Level 1

31 points

Aug 25, 2011 11:47 AM in response to Oliver W.

Cool Oliver!

I'll have to try out your mods. This process has put me on the path to using more NetRestore/NetBoot/NetInstall tasks. Of course, doing such things is one of the hats I wear at work, so I have some resources that the average computer owner may not.

In the days after my post, I've re-run the process several times, adding more to it each time. I've now got a NetRestore image that contains Snow Leopard 10.6.8 v1.1, with all current system updates applied, the three accounts that are put on every computer in our lab (2 admin accounts, 1 test account), each configured properly, Microsoft Office 2011 14.1.2, Adobe Acrobat Pro and other 3rd-party apps that we use here. Each has several updates applied, and is licensed and configured.

I've found it easy to build these images, after having gone through the basic process a couple of times. Now I have to get systematic about it, and keep better records! ;-)

The biggest caveat to this particular workaround is that as soon as Apple updates hardware in the Mac Pro, MacBook Pro, or iMac, currently selling version of that model will no longer be candidates for turning back to Snow Leopard. I'd guess that by Christmas 2011, this thread will be useless, as none of the Apple models at that time will run under Snow Leopard 10.6.8 (and there will not be any Snow Leopard compiled for new models, according to my Apple Tech).

cheers!

Wo von kommen Sie Oliver? Meine Frau kommt aus Aachen. Ich finde das wunderschön das diese Arbeit functionert unter ander Spräche auch!

Aug 25, 2011 11:27 PM in response to Roy Miller

I am sorry if this seems tangent to your post topic, but can/will your method work with dual booting Lion/SL ? There are a number of 3rd party educational programs that will eventually catch up to Lion but currently do not support it (Smartboard, EBeam, LotusNotes7). If one was looking for a short term (1 year or so) fix and Hd space was not a huge concern other than program files (not movies or anything like that) Would the methodology be the same except with partitions like most dual boot descriptions? (Is there some conflict with the lion restore partition in conjunction with A SL partiton?).

There is a chance that I will have to do this with 9 MBPs that arrived 7/2011 and your image process looks as though it would mean imaging 10.6.8 once and then mounting it in 9 MBPs... I hope I have that right. Does it matter if the computer running 10.6.8 is a desktop when you want to load these onto a MBP? I assume from your post ...no.. but I didn't see anything explicitly saying so and I am somewhat paranoid about my own ignorance.

Thank you for listening and your original post

Will

Aug 26, 2011 12:56 AM in response to williamfromkailua

Hi Will!

Even though your post wasn't addressed at me - from my point of view this should work out!

I'd suggest that you boot the MBP (or what else) into targe mode and create an additional partition on the hard disk using the GUI DiskUtility *without* deleting any of the existing partitions (Lion partition and Lion recovery partition).

After you have completed that you should proceed with step C.1 from Roy's tutorial and RESTORE the "Snow Leopard 10.6.8 System.dmg" you had generated into the *NEWLY* created partiotion - and not into Macintosh HD - because this would erase your existing Lion partition.

After that you should have the option to select between your bootable partitions on startup by pressing the alt key.

HTH,

Oliver

Roy Miller Author

Level 1

31 points

Aug 26, 2011 7:19 AM in response to williamfromkailua

Hi Will,

Does it matter if the computer running 10.6.8 is a desktop when you want to load these onto a MBP?

nope. Desktop, laptop, Xserve, whichever. I believe it is necessary that the system on which the image processing is done is running SL 10.6.8, so that you can use the System Image Utility from Server Admin Tools 10.6.8...

Oliver's suggestion sound reasonable - I know in my case, with my new MBP, I re-partitioned the drive into a two partition scheme, overwriting the original single Lion partition. This apparently deleted the Lion Recovery partition.... This Recovery partition is not exposed in the Disk Utility interface, and I was unaware that I was affecting it. In my case, it is no great loss, as it is likely this MBP will never run under Lion anyway.

as another note, I've purchased one of the Lion 10.7.0 USB Thumb drives. This did boot an older 2007 MBP, as well as the new 2011 MBP. Unfortunately, it does not boot my new 2011 Mac Mini. Therefore I'll extrapolate that it won't boot the new 2011 MBA either.

good luck Will - and make sure you read the correction to the original post where I've corrected the package name for getting the System Image Utility!

cheers!

Aug 26, 2011 9:42 AM in response to Roy Miller

I messaged earlier that I couldn't make it work - but I did. I had only updated to 10.6.7 but what I needed was 10.6.8 - I set the new mac up as a target drive and installed SL on a parition. I then ran the 10.6.8 combo update. Thanks for letting me know that I needed 10.6.8!! 🙂

Roy Miller Author

Level 1

31 points

Aug 26, 2011 11:05 AM in response to Princess Productions

Princess Productions wrote:

I messaged earlier that I couldn't make it work - but I did. I had only updated to 10.6.7 but what I needed was 10.6.8 - I set the new mac up as a target drive and installed SL on a parition. I then ran the 10.6.8 combo update. Thanks for letting me know that I needed 10.6.8!! 🙂

Yes, the new 2011 MBP was not in production when 10.6.7 was compiled - therefore the MBP must have OS version 10.6.8 or later!

glad it worked for you! 😎

Wanky

Level 1

0 points

Aug 26, 2011 4:18 PM in response to Roy Miller

Great instructions Roy!

I can now dual boot Snow Leopard and Lion on my new MacBook Pro which came with Lion.

- Instead of restoring the 'external source prepared in B.7' to the original Lion Macintosh HD as you did, I had already partitioned the hard drive and so I restored 10.6.8 to this new partition. Leaving the original Lion drive and Recovery drive intact.

I then went on to transfer just my applications from my iMac running 10.6.8 during the Snow Leopard set up screens. Perfect.

Churrrrs

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