The latest MacBook Pros and iMacs sport a new port, a Secure Digital (SD) memory card reader. The immediate assumption is that you will use the SD card slot for transferring videos and photos from a camera to the Mac. That's what a majority of users will use it for.

For the hardcore users out there, Apple decided to give the SD port super powers -- you can use it to build a bootable SD card. That bootable card can then become an awesome tool for performing emergency hard drive repairs, data recovery, recovering deleted files, and much more. This how-to will get you started on building your SD card offering you a few ideas along the way, but potential uses for this SD card are practically unlimited.

Difficulty level:
Medium

What you need:
> MacBook Pro or iMac 2009 model with built-in SD card slot

> Mac OS X installation DVD that shipped with your Mac.

> Recommended high speed 16GB or 32GB SanDisk Extreme III SD card; Minimum 8GB SanDisk Extreme III. Note: Other SD cards may work, but will be considerably slower. See this Apple support document for more information on compatible SD cards.

> Installation Disks for your favorite Mac OS X recovery utilities, applications or other tools.

> 90 minutes or more of free time.

Note: This how-to focuses on creating a personalized bootable rescue drive. You can use the retail Snow Leopard to create a bootable drive for any compatible Mac with an SD card port. Check with your OS X utility of choice to make sure it will work on a variety of machines after installation.  

Create a Bootable SD Card

1. Insert the SD card you want to use into the built-in card slot on your MacBook Pro or iMac.

3. Select the SD card inside of the left pane in Disk Utility.

4. Click on Partition; then under Volume Scheme change it to one partition

5. Under Volume information type the following:
    Name: MPB13_SD_BOOT (13 represents the model MacBook Pro)
    Format: Mac OS Extended (Journaled)
    Size: 15.59 GB for 16GB SD Card (accept maximum the default)
   
6. Click the Options button and select GUID Partition Table and click Ok.
   
7. Click Apply and then click Partition.

Disk Utility will prepare and format the SD card. Afterwards, you are ready to install Mac OS X onto the card.

Installing Mac OS X onto the SD Card

1. Insert the Mac OS X installation DVD that came with your MacBook Pro or iMac.

2. Double click the Mac OS X installation icon.

Note: The installation screen, for Mac OS X Leopard, will tell you that the installation will take approximately 11.6GB of space. This exceeds the space on an 8GB SD card by a wide margin. We'll resolve that problem shortly.

3. Select a Destination in this case that will be the SD card you prepared above.

4. Click Continue.

5. At the installation summary screen click Customize.

6. You will be presented with check list of items that will be installed. Uncheck all of the following: Printer Drivers, Additional Fonts, Language Translations, and X11. This will reduce a Mac OS X Leopard installation down to approximately 6.2GB. Click Done.

7. Click Install and Mac OS X will start to install onto the SD card. The installation will take an hour or more. Once it has completed click through any other screens that appear accepting the defaults on each one.

You are now ready to boot your Mac from the SD card. Restart your Mac while pressing and holding down the Option key. You will eventually be presented with the Startup Manager -- select your SD card and your Mac will boot from it as shown below.

Installing Your Favorite Disk Utilities, Tools and Other Applications

Once you've verified that your SD card is bootable you'll have to decide what applications you want to install and how you might need to customize Mac OS X on your new tiny postage sized Mac hard drive. Yes, believe it or not, your SD card is now a full fledged bootable Mac hard drive and it will act just like one. In fact, you can take it with you and boot any Mac of the same model as it was built on, which in this case was a 13-inch MacBook Pro.

We went to my software library and installed the following applications on our emergency SD rescue card: DiskWarrior, Drive Genius 2, FileSalvage, and TechTool Pro 5. They all installed just as they would normally, updated automatically, and accepted serial numbers as needed for activation. We then dragged their icons to the Dock for easy access after booting off of the SD card. In addition to that, we added icons for commonly used tools for trouble shooting: Activity Monitor, Console, Terminal, Disk Utility, and System Profiler.