sudo /Applications/Install\ macOS\ Sonoma.app/Contents/Resources/createinstallmedia --volume /Volumes/MyVolume (Change “Sonoma” to “Ventura” or “Monterey” as needed)
You now have a portable, bootable Mac environment. Whether you’re testing a new OS, running legacy software, or simply keeping a disaster recovery tool in your bag, this setup puts you in control. install mac os on external hard drive
Carbon Copy Cloner (free trial, highly recommended) or SuperDuper! (free version available). sudo /Applications/Install\ macOS\ Sonoma
sudo /Applications/Install\ macOS\ Catalina.app/Contents/Resources/createinstallmedia --volume /Volumes/MyVolume running legacy software
sudo /Applications/Install\ macOS\ Big\ Sur.app/Contents/Resources/createinstallmedia --volume /Volumes/MyVolume