mac.column.ted: Create a Leopard startup flash drive

It's not as easy as you might think.

Ted Landau

April 2008

It's that time again. Time for me to check out the current status of creating an emergency boot drive ? this time one with Leopard installed. Let's cut right to the chase: the ease of creating these startup drives continues to move in one direction: from bad to worse.

Creating a pint-sized custom startup drive, with your own selection of utilities, was a breeze in Mac OS 9 or earlier. It became much more difficult in Mac OS X, but was still manageable, all the way through Panther. With Tiger, most previously successful methods would no longer work; you had to be increasingly "creative" to find anything that would get the job done. I detailed this unhappy trend in a pair (one and two) of previous columns here at MacFixIt. In a further article, I provided step-by-step details for a workable solution ? installing a version of Tiger on a relatively meager in size (but cost-effective) 1GB flash drive.

First off, there's the question as to why Apple continues to make this worthwhile task so difficult to do. The answer I keep hearing is that Apple's legal department insists on putting up these obstacles, supposedly to protect the copyright of Apple's OS. I am not sure this is the real reason, or exactly what dangers Apple needs protecting from, but that's what I hear. Apple does license the software for creating a bootable CD/DVD to a few companies ? primarily disk repair utilities such as Alsoft, Prosoft and Micromat. But Apple is very restrictive here. Even if you are a dues-paying developer and are willing to pay extra for a license, you have to prove to Apple that you are truly worthy. And even those privileged companies have not yet been given a license to use Leopard on a disc. That's right. Alsoft's DiskWarrior and Prosoft's Drive Genius 2, for example, still ship with Tiger. I assume Apple will eventually permit these vendors to move up to Leopard, but it hasn't happened yet. This is the current sorry state of affairs.

What's the problem?

"Wait a minute," you may be saying at this point, "What's so difficult about making a custom startup drive? Can't you simply install Leopard on any drive that is large enough to hold the essential software?" Yes, it is certainly possible to boot from an external USB or Firewire hard drive. There are several brands of portable (bus-powered) drives that are reasonably compact and would do the job. But they are still bigger and more expensive than what I had in mind. My goal was to find a very inexpensive and ultra-portable boot drive that could hold a custom set of troubleshooting utilities ? allowing you to keep the drive handy at all times, conveniently taking it with you when you travel, ready for whenever an emergency or any unexpected problem occurs.

Another potential solution would be to install Leopard on an 8GB or greater flash drive. However, while the size here is ideal, these larger capacity flash drives exceed the price limit I was hoping to stay below. I also found that running a full install of Mac OS X from a flash drive to be irritatingly slow (launching almost any software took well over a minute).

To keep both size and cost to a minimum, I was hoping to use a 4GB or less USB flash drive. You can get one of these drives for less than $20 and easily keep it in your pocket. True, such a drive will only boot an Intel Mac, but I was willing to accept that limitation.

Once you get down to 4GB, however, the essential OS X software for a "full" install will no longer fit, so the Leopard DVD won't even let you initiate an install to such a drive. The primary solution here is to edit the contents of a Mac OS X Install DVD down to less than 4GB and install that onto a flash drive. The idea is that the flash drive will boot from this stripped-down version of the OS, just as the DVD itself boots. From my experience, a drive with this OS also runs significantly zippier than one holding a full OS install. This is exactly what I did in the article I previously cited, where I managed to get the Tiger system software down to less than 1GB and still have enough room left over for adding my array of third party utilities.

A few weeks ago, I finally got around to checking out whether the same procedure would work with Leopard. It did not. Two issues emerged:

First, with Leopard, the best I could do was get the system software down to around 1.5GB. That's what led me to move up to a 4GB flash drive. But my troubles here were still not over. For reasons that remain mysterious (at least to me), I could never get my Mac to even recognize a 4GB drive, with Leopard installed, as bootable. For example, even when all I did was strip out non-essential contents from a Leopard Install DVD image, to get it down to less than 4GB, and then directly copy the contents to a flash drive (using either Disk Copy or SuperDuper!), the drive would not boot. To be clear, it would show up in the Startup Disk System Preferences pane as a potential startup disk. But it would not boot if selected. Similarly, it would not show up if you held down the Option key at startup, to get a display of all available bootable drives. With Tiger installed instead, the drive would boot just fine. It almost seems as if, with Leopard installed, the Mac refuses to boot from any media less than 8GB. There may be a way around this logjam, but I have not been able to find it.

Second, with the Install-DVD-OS-to-flash-drive solution, you will likely want to find a substitute for the Installer (which is the application that launches by default when you startup). What you want instead is an application launcher utility that allows you to launch the other software that you add to the drive. With my Tiger solution, I used a utility called QuickerPicker ? and found a way to modify the system software so that the flash drive would launch QuickerPicker instead of Installer at startup. Unfortunately, these modifications no longer work in Leopard. True, you could simply choose to stick with Tiger here, but this won't do if you have a newer Mac that only boots from Leopard.

[Note: In a pinch, you could let Installer launch and open Terminal (via its Utilities menu). You could then launch applications from Terminal. To make this easier to do, copy the "open" file from the /usr/bin directory on your Mac to the same directory on your flash drive, as it is not included on the Install DVD. But none of this is very user-friendly. I was seeking a less "geeky" solution.]

Finally, you might ask, "Why bother with using a flash drive at all, as opposed to a DVD-R disc?" The answer is that a flash drive is faster and its contents can be easily modified (so as accommodate software updates, for example). Additionally, a write-enabled drive may be required for some third-party utilities to even launch.

What's the (less-than-ideal, but the best I could do) solution?

Having failed with a 4GB drive, I reluctantly moved up to an 8GB drive. In my first attempt, I tried directly copying the entire Leopard Install DVD to the drive. Success at last! It booted and launched the Installer, just as would the Install DVD. Resigned to working with the more expensive 8GB drive, I turned my attention to getting it to boot using an application launcher instead of the Installer. As with Tiger, I selected QuickerPicker. I was initially concerned that it would no longer work in Leopard, but it did just fine. I did search for a more modern alternative utility, but found none that would work (presumably because they require resources not included in the minimal OS on the Install DVD). I could not even get Path Finder to work (as I had been able to do with Tiger).

Here are the step-by-step instructions detailing what I did get to work:

  1. If necessary, use Disk Utility's Partition option to reformat the flash drive as GUID Partition Table or Apple Partition Map. The critical thing is that it not be a Master Boot Record partition.

  2. Use Disk Utility's Restore feature to copy the Leopard Mac OS X Install DVD to the 8GB flash drive.

  3. Temporarily make invisible files visible in the Finder, using one of any number of utilities (such as Invisibility Toggler). You need to do this to access the otherwise invisible folders mentioned in the next steps.

  4. Copy QuickerPicker to the Applications folder on the flash drive. Next, to the same folder, add whatever other utilities you want on the drive. Optionally, if needed to free up space, delete unwanted applications and package files (by trashing all the unwanted stuff in the /Applications folder and all the packages in the /Optional Installs and /System/Installation/Packages folders).

  5. Open the /private/etc/rc.install file in TextEdit. Locate the line that begins "The Launcher is responsible for the progress bar..." Delete everything from that line to the end of the document. Add the following to the end of the document:
    The second line will likely not have any effect, but it won't hurt.
    [Note: This is the big change from the more elegant procedure I used in Tiger. The switch was needed because the Tiger procedure no longer worked.]

  6. Save the edited file, clicking to Overwrite when asked. If you instead get a message that claims you cannot modify the file at all, go to the Info window for the flash drive and enable the "Ignore Ownership..." checkbox. Then try to save the file again.

  7. Open the /etc/rc.cdrom file in TextEdit. Locate a line that reads: mount -u -o ro / and change it to mount -u /
    Save this modified file.

  8. You now have a functional emergency flash drive and are ready to use it. Restart the Mac. As soon as you hear the startup chime, hold down the Option key. At the screen that appears, select to startup from the flash drive. The drive should boot successfully and launch QuickerPicker.

  9. Select Rescan Applications from QuickerPicker's File menu to get your added applications to appear. Launch any program you wish. Not all added software will work, but most troubleshooting utilities will do just fine. Quit any open utility to return to QuickerPicker.

When you are done, you will need to do a hard shut down (such as by holding down the Power button until your Mac shuts off) to exit. I was not able to get the Restart or Shut Down commands to work. You can then reboot, as normal, from your internal hard drive.

This solution is not as cheap, nor as easy to create nor as simple to use as I would have preferred. But it works ? at least until Apple changes things again. I don't claim to have reached the end of what may be possible here. If anyone knows how to improve on this procedure, by all means let me know.

Addendum: In my testing, I used three different flash drives, of different sizes and from different companies. I used a 4GB DataTraveler from Kingston, an 8GB cruzer from SanDisk and a 32GB Survivor from Corsair. They all performed well. I have no reason to believe that any problems or successes I had were due to a specific drive or brand, but I cannot entirely rule that out. I can say that my preferred choice overall was the cruzer. It had the most convenient design (unless you need the extra external protection of the Survivor) and appeared to be the fastest (in my informal testing).

To send comments regarding this column directly to Ted, click here. To get Ted's latest book, Take Control of Your iPhone, click the link.

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  • Micromat
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