System Administration Uncategorized

Casper Imaging in the Recovery HD and A Lightweight Netboot Image

[UPDATE] JAMF has set the feature request for this as under review

OS X Netboot images can be many GigaBytes in size, which is not great when multiple client computers are trying to download that image from the network, especially if the infrastructure is not there to support it.

I wanted to create a lightweight netboot image to run Casper Imaging.  Not only would this save network bandwidth, but it would also be faster, which means you could image more computers in a shorter amount of time.  In addition, this could even be used to replace the existing Recovery HD so the computer could be imaged without netbooting at all.

Fortunately and unfortunately for me, Apple has already done most of the work on creating a minimal OS: the Recovery HD.  Even the latest version in Mavericks, the recovery partition weighs in under 1GB.

For many months I tried different ways to get Casper Imaging to run in the Recovery HD.  It was easy enough to get the app installed to the Recovery partition and show up in the Utilities window.  But the app does not launch from this mode.

From what I can tell, I think the Recovery partition is 64-bit and won’t launch the 32-bit Casper  Anytime I try to launch it, I end up with the error:

illegal instruction 4

I tried adjusting the .plist to 10.6 but I don’t think this can be changed after the app has been compiled.  I also tried force the Recovery HD to boot into 32-bit mode, but the setting doesn’t stick when running this command:

sudo systemsetup -setkernelbootarchitecture i386

most likely due to the partition being read-only.  I also tried to apply this setting when I was building the custom Recovery HD, but it only ended up booting to the prohibitory sign.


I believe it should still be possible to image a computer using asr , but it would require more of a manual setup.  It would be ideal if this could be integrated with the Casper Imaging because management would remain basically the same.  While waiting for JAMF to update their app to 64-bit, I will continue to work on this.

Star Trek LCARS Casper Imaging Bonus

Use this Star Trek-themed wallpaper for your existing Netboot images and propagate the Federation’s reach!



4 replies on “Casper Imaging in the Recovery HD and A Lightweight Netboot Image”

Such an awesome idea. I tried everything from your other post before realizing that Casper imaging wasn’t 64Bit, what a bummer. I’ve been on their case about making their apps retina optimized on the mac now i have something else to hassle them about too.

I looked into this a few years ago. The issue we were running into wasn’t that Casper Imaging wasn’t 64bit, it was that Casper Imaging was build using Xojo (RealBasic), and one of the plugins (MBS Mac Plugin set) it was built with needed to call on Finder. If Finder wasn’t running, Casper Imaging would throw an error and refuse to launch. We put in a request with JAMF to address this more than 4 years ago, but it still hasn’t been resolved. At the time we were told they were rewriting all of their apps in Xcode, but so far they’ve only updated Self Service and Recon.

Very interesting. Is your request a Feature Request, or just something you personally asked them? I wonder if you could fake it out by creating a little fake process named Finder…

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