Modern macOS deployments have moved away from the monolithic or “thick images” used primarily in cloned rollouts. Best practices dictate the use of automated deployment tools, such as OS X Server’s Netinstall, Puppet, or other third-party tool that installs macOS onto the devices, and then performs silent installations of settings, configurations, and software packages.

SEE: Software usage policy (Tech Pro Research)

But what about the devices that are otherwise unavailable on the network? Systems that may be offline or air-gapped due to security concerns, or those that may be housed in remote locations and have poor connectivity yet must still be updated. For these types of devices–the ones just outside the reach of the IT department’s deployment tools or company infrastructure–creating a USB installer is the next best option and often the only viable option. Here are step-by-step instructions on how to create a bootable USB installer for macOS Mojave.


  • Mac computer with OS X (10.8 or newer)
  • macOS Mojave (10.14) installer downloaded from the Mac App Store
  • Apple ID
  • Admin credentials
  • USB flash drive or hard drive (8 GB free space or more)

How to build the USB-based installer for macOS Mojave

1. Log on to the Mac computer and mount the USB device.

2. Launch the Terminal and enter the command below to convert the USB device to installer media. Note: The contents of the drive will be erased during the conversion process (Figure A).

Figure A

sudo /path/to/Install\ macOS\ --Volume /Volumes/path/to/USB --nointeraction

3. You’ll be required to enter admin credentials when prompted for the password. Once authenticated, the command will begin erasing the disk (Figure B).

Figure B

4. Upon completion of the formatting process, the files will be copied to the drive (Figure C).

Figure C

5. The disk will be made bootable as the process completes successfully. You can now unmount the disk and use it to perform an update or clean install on your Mac computers (Figure D).

Figure D