install snow leopard external hard drive

Drive Preparation

1. Open Disk Utility in your Utilities folder.

2. After DU loads select your hard drive (this is the entry with the mfgr.'s ID and size) from the left side list. Click on the Partition tab in the DU main window.

3. Under the Volume Scheme heading set the number of partitions from the drop down menu to two. Size each to your preferences. Click on the Options button, set the partition scheme to GUID then click on the OK button. Set the format type to Mac OS Extended (Journaled.) Click on the Partition button and wait until the process has completed.

4. Select the first partition you just created (this is the sub-entry under the drive entry) from the left side list. Click on the Erase tab in the DU main window.

5. Set the format type to Mac OS Extended (Journaled.) Click on the Security button, check the button for Zero Data and click on OK to return to the Erase window.

6. Click on the Erase button. The format process can take up to several hours depending upon the drive size.

7. Repeat steps 4-6 for the second partition.

8. After formatting is completed quit DU.

To install Snow Leopard:

Boot from your Snow Leopard Installer disc. When the installer is ready with rinstalling Snow Leopard.

This only works with Snow Leopard, not Leopard as you've stated: "reboot into the disk chose the install leopard disk."

Maybe you will tell me what model you have. Open System Information and post what you finde displayed for Model Identifier. I think you are trying to install Snow Leopard from a model that came with Lion pre-installed. If so what you want to do is far more complex because your computer cannot be booted from a retail Snow Leopard DVD.

I think you misunderstood. Your computer requires Snow Leopard 10.6.6 or later. The retail Snow Leopard DVD installs 10.6.3. It cannot boot your model. Oh, and Snow Leopard is $29.00, not $40.00.

Anyway, here's what you can do:

How To Run Snow Leopard On A New Mac

This does not apply to new Mac Minis or MacBook Airs. When newer models are introduced that also require Lion for hardware support, the techniques described below will no longer work with the possible exception of using Parallels 7.

What has to be done:

1. Create a new partition on the hard drive.
2. Get a clone of a 10.6.8 Snow Leopard system. Put the cloned Snow Leopard system onto the new partition.
3. In your case rather than installing onto a partition on your hard drive, just install it on your external hard drive.

Step One: Create a new partition on the hard drive

To resize the drive and create a new partition do the following:

1. Restart the computer and after the chime press and hold down the COMMAND and R keys until the menu screen appears. Alternatively, restart the computer and after the chime press and hold down the OPTION key until the boot manager screen appears. Select the Recovery HD and click on the downward pointing arrow button.

After the main menu appears select Disk Utility and click on the Continue button. Select the hard drive's main entry then click on the Partition tab in the DU main window.

2. You should see the graphical sizing window showing the existing partitions. A portion may appear as a blue rectangle representing the used space on a partition.

3. In the lower right corner of the sizing rectangle for each partition is a resizing gadget. Select it with the mouse and move the bottom of the rectangle upwards until you have reduced the existing partition enough to create the desired new volume's size. The space below the resized partition will appear gray. Click on the Apply button and wait until the process has completed. (Note: You can only make a partition smaller in order to create new free space.)

4. Click on the [+] button below the sizing window to add a new partition in the gray space you freed up. Give the new volume a name, if you wish, then click on the Apply button. Wait until the process has completed.

You should now have a new volume on the drive.

It would be wise to have a backup of your current system as resizing is not necessarily free of risk for data loss. Your drive must have sufficient contiguous free space for this process to work.

Step Two: Obtain a clone of a Snow Leopard system:

You will need access to a Mac already running Snow Leopard. You will need a 16 GB USB flash drive or an external hard drive to which you can clone the Snow Leopard system from the Mac that has Snow Leopard installed. Alternatives are:

Option One:

1. Install a new Snow Leopard system onto a USB flash drive. Boot the Mac used for installing with the USB flash drive. Update the flash drive system to 10.6.8 using the Mac OS X 10.6.8 Update Combo v1.1 to update Snow Leopard. Verify that you can boot the Mac with the USB flash drive.
2. Take the USB flash drive to your new Mac and try booting from it. If it works then clone the system from the flash drive to the newly made partition:

Clone using Restore Option of Disk Utility

1. Open Disk Utility from the Utilities folder.
2. Select the destination volume from the left side list.
3. Click on the Restore tab in the DU main window.
4. Check the box labeled Erase destination.
5. Select the destination volume from the left side list and drag it to the Destination entry field.
6. Select the source volume from the left side list and drag it to the Source entry field.
7. Double-check you got it right, then click on the Restore button.

Destination means the new partition on the internal drive. Source means the USB flash drive.

Option Two:

If you have a large enough external drive you can erase and use, then it would be easier to just clone the entire Snow Leopard system from the source Mac computer to the external drive.

Clone using Restore Option of Disk Utility

1. Open Disk Utility from the Utilities folder.
2. Select the destination volume from the left side list.
3. Click on the Restore tab in the DU main window.
4. Check the box labeled Erase destination.
5. Select the destination volume from the left side list and drag it to the Destination entry field.
6. Select the source volume from the left side list and drag it to the Source entry field.
7. Double-check you got it right, then click on the Restore button.

Destination means the external drive. Source means the Snow Leopard Mac's internal drive.

After cloning verify that it will boot the source Mac. If so then take the external drive to your new Mac boot with it. If all is well then restore the clone to the new partition on your new Mac:

Restore the clone using Disk Utility

1. Open Disk Utility from the Utilities folder.
2. Select the destination volume from the left side list.
3. Click on the Restore tab in the DU main window.
4. Check the box labeled Erase destination.
5. Select the destination volume from the left side list and drag it to the Destination entry field.
6. Select the source volume from the left side list and drag it to the Source entry field.
7. Double-check you got it right, then click on the Restore button.

Destination means the new partition on the internal drive. Source means the external drive.

If the above seems too daunting then you might consider running Snow Leopard inside an emulator such as Parallels 7. You are permitted to install a single copy of Snow Leopard inside a virtual machine. You will need to first purchase a copy of Parallels 7 and install it on your new Mac. Create a new virtual machine configured for Mac OS X. You may then install Snow Leopard in the virtual machine then download Mac OS X 10.6.8 Update Combo v1.1 and update to 10.6.8. Be sure to include Rosetta in your initial Snow Leopard installation. Rosetta is not installed by default rather it's an optional install.

They did sell you the latest version that was produced as a retail DVD. Subsequent versions of Snow Leopard were special builds made for new hardware. Apple never released a retail DVD beyond 10.6.3. That's just the way it is.

Yes, basically I am telling you that the retail Snow Leopard you have cannot boot your computer nor be installed on it directly. Either you obtain a clone of 10.6.8 or create your own by first installing 10.6.3 from the DVD you have then updating it to 10.6.8. You would need to do this on an older computer model that can boot from your Snow Leopard DVD.

As an alternative you can purchase Parallels and install your Snow Leopard version as a virtual machine as I've indicated in the last paragraph. The advantage of this is running both operating systems concurrently.

What good will that do you until you are able to create a bootable clone of 10.6.8 that you can use? Furthermore, if you are using a FileVault encrypted drive then I would leave well enough alone especially if you don't have a backup.

Just find someone with an older Mac model you can use to perform the surgery. Get yourself a 16 GB USB flash drive on which to plant the 10.6.8 system.

Which is what I've already suggested you can do but only if you can do it on a Mac that can boot Snow Leopard 10.6.3.

Wouldn't it be easier just to upgrade to FCPX which is compatible with Lion/ML?

No, I'm not annoyed, really. 😀 It's just that your goal is not easily attained when you have new hardware but an out of data OS, and you don't have any other Macs with which to work.

All you need to complete the task is a Mac that will boot 10.6.3. Unfortunately, that's not something I can help you with.

First of all, thank you, Kappy, for the great info. Fabulous.

One question: You mention installing a copy of SL in Parallels 7 on a Mac at the end of the step-by-step post about 1/3 of the way down the page. My understanding of Parallels, and from the appearance of their website, was that only Windows could be installed there. Am I wrong? (hope, hope)

My Achille's Heel is GoLive. It requires SL, but my MBA is a Lion-only machine. Partitioning its hard drive to install SL on one side is out (can't physically be done), which leaves either booting into SL on an external drive or...maybe....Parallels?

Which option makes more sense (and which is safer long term)? The ideal scenario would be to have it on the Air's drive, but space on the smaller SSD is an issue. Am looking at this as a possible internal replacement, which would alleviate that particular concern:

http://eshop.macsales.com/shop/SSD/OWC/Aura_Pro_Air_2011

I still have two computers running 10.6.8--a Mini and a MBP late 2009--so there is access to a current copy.

Suggestions? (Please, not "Move to Dreamweaver," etc...I hate that program with a passion.)

There really is no option for GoLive than the one you asked not be mentioned. There are other similar programs such as Freeway Pro, but really it's nearly impossible to replace GoLive except by, you know what. I have a good friend who is/was in the same boat. I know your pain, but I know of no satisfactory relief.

Parallels, VM Fusion, and VirtualBox can all emulate other OSes than Windows. It is possible to emulate OS X, but it is illegal to do so with some caveats. One can run a single instance of Snow Leopard Server or a single instance of Lion or Mountain Lion Client. Parallels 8 may be required for the latter.