This procedure will guide you through the steps to creating a bootable external drive that contains the latest Casper bootable image on it.

Step-by-step guide

To create the bootable Casper drive, follow the below procedure:


NOTE! You will need the following items before you begin:

  1. A 16GB or larger external drive (e.g. USB, Thunderbolt, etc.). All data will be erased on this drive!
  2. The most current Netboot DMG, located at \\\Trinity\Software\Mac\Imaging\NetBoot DMGs\
  3. You must have an administrator account on the computer you use to set up the drive
  1. Plug in your external drive to your Mac.
  2. Open Disk from /Applications/Utilities/
    Finding the Disk Number
  3. As indicated by Circle #1, select the top level of your USB drive's listing in the left window pane.
  4. Press Command+I or press the "Get Info" button to see the window on the right side of the above graphic
  5. As indicated by Circle #2, make note of the contents to the right of the "Disk Identifier" field. You will need it in a following step.
  6. If you haven't already, copy the Netboot DMG to a location on your computer that you can access.
  7. Open from /Applications/Utilities/
  8. Type the following command, replacing the fields indicated:


    sudo dd if=/path/to/netboot-file.dmg of=/dev/disk-identifier-here bs=1m
    Example: sudo dd if=/Users/override/Desktop/Restore-9.82-TTSMACDEPLOYM-(15C50).dmg of=/dev/disk3 bs=1m

     In the above command, "if" indicates "input file" (i.e. the Netboot DMG) and "of" indicates "output file" (i.e. the USB drive).

    IMPORTANT! Re-read your above syntax to make sure you have entered the correct "of" device identifier, or else you could accidentally wipe a drive you need!


  9. After you have checked your syntax, press "Return" and then enter the account password that is currently logged in.

  10. The process will run silently until it either completes successfully or fails with an error. The usual time to copy the DMG file is between 10-15mins.
  11. If you complete successfully, then eject the external drive through Disk Utility or by dragging the drive to the Trash.
  12. To test, insert the external drive into a computer that is powered off. Hold the "Alt/Option" key, and then power the computer on. If you were successful, you should see an orange-colored volume with the name "TTS-Netboot-9.xx" (e.g. TTS-NetBoot-9.82.nbi). Click the arrow below this volume to begin the boot process to resume booting using the selected boot device.

Package Repo Cloning (Optional)

This portion of the procedure is optional and only recommended for advanced users. Once you have verified that your external drive boots correctly, you can create a local package cache on the bootable drive that Casper Imaging can use instead of using a network Distribution Point. This option can be useful if the computer to be imaged does not have network access or lacks sufficient bandwidth to make Netboot imaging practical. The drawback to this method is that the package repo must be continually refreshed in order to stay up-to-date.

  1. Start by plugging in your external bootable drive, if it is not already plugged in.
  2. Create a folder under the root directory of the drive called "Casper". Inside of that folder, create another folder called "Packages".
  3. Open "Casper Admin" and log in with your Casper credentials.
  4. In Finder, click on the "Go" menu and then select "Go to Folder...". Enter the following path: /Volumes/casper-dp/Packages/
  5. Copy the needed packages for your intended imaging configuration, which you can retrieve while viewing the configuration in Casper Admin, to the bootable drive's /Casper/Packages/ directory.
  6. Quit from Casper Admin.
  7. To test, reboot a computer using the bootable Casper drive and open Casper Imaging.
    Choosing a local drive 
  8. As shown in the above graphic, click the "Distribution Point" dropdown. Select the "Choose Local Drive..." option from the list, and then navigate to the Casper/Packages/ directory on your bootable Casper drive. Casper Imaging will now copy imaging data to the computer from your local drive instead of from a network file distribution point.

    If the file Casper Imaging needs is NOT present on your bootable Casper drive, it will silently skip that package and log the failure in /var/log/jamf.log, which you can view after imaging is complete.