createinstalliso

Creates a bootable ISO image from a macOS installer application. This image can then be used to install macOS on a physical or virtual machine.

Table of Contents

• Introduction
• Requirements
• Compatibility
• Installation
• Usage
  • Command line arguments
  • Example
• Troubleshooting
  • Alert during macOS installation
• References
  • Installer application types
  • Required external commands
  • Exit status and messages
• License

Introduction

If you have ever needed to install macOS on a new computer, you have probably discovered the ability to create a bootable USB flash drive or other volume by using the createinstallmedia command included in the downloaded macOS installer: Create a bootable installer.

In case you need a bootable ISO image instead, you can find a lot of shell scripts in forums that create such an ISO image for certain macOS versions. However, they are often only written for a single macOS version and cannot adapt to the specific macOS version contained in the installer.

The purpose of this program createinstalliso is to create a bootable ISO image from a downloaded full macOS installer. In addition, the program should:

• Automatically adapt the strategy used to create the ISO image to the installer application type, thereby supporting a wide range of macOS versions (see: Compatibility).
• Look and feel like Apple's createinstallmedia command (e.g. handling of command line arguments, wording for error and progress messages, status codes used when exiting).
• Behaving like a standard command line program (e.g. Ctrl-C interruptibility, proper cleanup of resources before exiting), even though it is a Bash script.

Requirements

To run createinstalliso you need:

• A machine running Mac OS X Snow Leopard 10.6 or later.
• An administrator user and password required for the use of the sudo command.
• A downloaded full macOS installer for Mac OS X Lion 10.7 or later.

Note: Make sure that you have downloaded a full macOS installer which should have a size of at least 5 GB.

Compatibility

macOS version

The table below shows:

• Whether a macOS version can run createinstalliso.
• Which macOS installers can be used to create an ISO image with this particular macOS version.

| macOS | Version | Can run createinstalliso | Can use installer for | |-----------------------|---------|:----------------------------:|-----------------------| | Mac OS X Cheetah | 10.0 | No | N/A | | Mac OS X Puma | 10.1 | No | N/A | | Mac OS X Jaguar | 10.2 | No | N/A | | Mac OS X Panther | 10.3 | No | N/A | | Mac OS X Tiger | 10.4 | No | N/A | | Mac OS X Leopard | 10.5 | No | N/A | | Mac OS X Snow Leopard | 10.6 | Yes | 10.7 - 10.11 | | Mac OS X Lion | 10.7 | Yes | 10.7 - 10.11 | | OS X Mountain Lion | 10.8 | Yes | 10.7 - 10.15 | | OS X Mavericks | 10.9 | Yes | 10.7 - 12 | | OS X Yosemite | 10.10 | Yes | 10.7 - 12 | | OS X El Capitan | 10.11 | Yes | 10.7 - 13 | | macOS Sierra | 10.12 | Yes | 10.7 - 13 | | macOS High Sierra | 10.13 | Yes | 10.7 - 15 | | macOS Mojave | 10.14 | Yes | 10.7 - 15 | | macOS Catalina | 10.15 | Yes | 10.7 - 26 | | macOS Big Sur | 11 | Yes | 10.7 - 26 | | macOS Monterey | 12 | Yes | 10.7 - 26 | | macOS Ventura | 13 | Yes | 10.7 - 26 | | macOS Sonoma | 14 | Yes | 10.7 - 26 | | macOS Sequoia | 15 | Yes | 10.7 - 26 | | macOS Tahoe | 26 | Yes | 10.7 - 26 |

Installer version

The table below shows:

• Which macOS version is required to use createinstalliso with a particular macOS installer.

| Installer for | Version | Required macOS version | |-----------------------|---------|:----------------------:| | Mac OS X Cheetah | 10.0 | N/A | | Mac OS X Puma | 10.1 | N/A | | Mac OS X Jaguar | 10.2 | N/A | | Mac OS X Panther | 10.3 | N/A | | Mac OS X Tiger | 10.4 | N/A | | Mac OS X Leopard | 10.5 | N/A | | Mac OS X Snow Leopard | 10.6 | N/A | | Mac OS X Lion | 10.7 | 10.6 or later | | OS X Mountain Lion | 10.8 | 10.6 or later | | OS X Mavericks | 10.9 | 10.6 or later | | OS X Yosemite | 10.10 | 10.6 or later | | OS X El Capitan | 10.11 | 10.6 or later | | macOS Sierra | 10.12 | 10.8 or later | | macOS High Sierra | 10.13 | 10.8 or later | | macOS Mojave | 10.14 | 10.8 or later | | macOS Catalina | 10.15 | 10.8 or later | | macOS Big Sur | 11 | 10.9 or later | | macOS Monterey | 12 | 10.9 or later | | macOS Ventura | 13 | 10.11 or later | | macOS Sonoma | 14 | 10.13 or later | | macOS Sequoia | 15 | 10.13 or later | | macOS Tahoe | 26 | 10.15 or later |

Installation

Open Terminal, which is in the Utilities folder of your Applications folder, and type or paste the following commands into Terminal:

• Download the createinstalliso file.

  curl -fOSs https://raw.githubusercontent.com/BITespresso/createinstalliso/master/createinstalliso
  

• Make the downloaded script executable.

  chmod +x createinstalliso
  

• A good practice is to keep your shell scripts in the bin folder in your home directory. If it does not already exist, create it and move the script to this folder.

  mkdir -p ~/bin
  mv createinstalliso ~/bin/
  

• You might also want to hide the bin folder from the Finder.

  chflags hidden ~/bin
  

Note: Of course you can also choose a different folder such as /usr/local/bin to save the script.

Usage

Just like Apple's createinstallmedia command createinstalliso must be run as root user. Depending on where you saved the script, the command will look like:

sudo ~/bin/createinstalliso --isodirectory <path to ISO directory> --applicationpath <path to OS installer application> [--nointeraction]

Command line arguments

The command createinstalliso requires the following two command line arguments:

• --isodirectory (or -i) must be followed by a path to a directory where the installer ISO image file will be created.
• --applicationpath (or -a) must be followed by a path to a copy of the OS installer application to create the bootable ISO image from.

The name of the ISO image to be created is made up of the name of the installer and has the extension iso (e.g. Install macOS Catalina.iso). If such a file already exists in the specified destination directory, you will be prompted for confirmation before this file is overwritten. If you do not care about overwriting an existing file and do not want to be prompted, you can add the command line option --nointeraction.

If you want to suppress user interactions when running the command and always allow the required actions, you can add the option:

• --nointeraction (or -n) causes an existing ISO image file to always be overwritten.

Example

The following example show the steps required to create an ISO image from a macOS Catalina installer:

• Open Terminal, which is in the Utilities folder of your Applications folder.

• Type or paste the following command into Terminal, then press Return to enter the command. This assumes that the installer is still in your Applications folder, and you have moved createinstalliso to the ~/bin folder.

  sudo ~/bin/createinstalliso --isodirectory ~/Desktop/ --applicationpath /Applications/Install\ macOS\ Catalina.app/
  

• When prompted, type your administrator password. Terminal doesn't show any characters as you type. Then press Return.

• Terminal shows the progress as the bootable ISO image is created.

• When Terminal says that it's done, you will find the bootable ISO image Install macOS Catalina.iso in the folder you specified (here: ~/Desktop).

• You can now quit Terminal.

Troubleshooting

Alert during macOS installation

If you try to install macOS using the ISO image you created, you may see an alert that says the application can't be verified and may have bee