Page 1 of 1

Welcome to the Tweaking4All community forums!
When participating, please keep the Forum Rules in mind!

Topics for particular software or systems: Start your topic link with the name of the application or system.
For example “MacOS X – Your question“, or “MS Word – Your Tip or Trick“.

Please note that switching to another language when reading a post will not bring you to the same post, in Dutch, as there is no translation for that post!

macOS - Create boot...
Clear all

[Solved] macOS - Create bootable ISO install disk from Monterey

1 Posts
1 Users
0 Reactions
Famed Member Admin
Joined: 11 years ago
Posts: 2716
Topic starter  

The idea is to make an ISO file so we can create a virtual machine with (for example) VMWare Fusion on my Mac that runs Ventura.
This way I can do a few tests with the older Monterey OS.

1. In the Apple Store get the Monterey Install app.

This will most likely open a window at some point wanting to install Monterey - of course we do not want to do this.
In the menu of the installer Quit the installer.

You should still see "Install macOS Monterey" in your Applications folder.

2. Run these steps, make sure you have at least app.16Gb disk space available.

sudo hdiutil create -o /tmp/Monterey -size 16g -volname Monterey -layout SPUD -fs HFS+J
sudo hdiutil attach /tmp/Monterey.dmg -noverify -mountpoint /Volumes/Monterey
sudo /Applications/Install\ macOS\ --volume /Volumes/Monterey --nointeraction
hdiutil eject -force  /Volumes/Install\ macOS\ Monterey
hdiutil convert /tmp/Monterey.dmg -format UDTO -o ~/Downloads/Monterey
mv -v ~/Downloads/Monterey.cdr ~/Downloads/Monterey.iso
sudo rm -fv /tmp/Monterey.dmg

You could throw this in a script, if you'd like. I prefer to go through each step to see what goes wrong, IF something goes wrong.

What these steps do:

- Create a temporary disk image
- Attach the temporary disk image (mount)
- Have the Monterey Installer create install media on that temporary disk image
- Eject the temporary disk image
- Convert temporary disk image to CD/DVD format (CDR file)
- Rename the CDR image file to ISO
- Remove the temporary disk image

You should now have a Monterey ISO.