The following tutorial is about creating a MacOS Big Sur ISO file. You can use this file for building a VMWare, a Hackintosh or just for installing MacOS on a different Volume/Drive. I myself used the file to install MacOS Big Sur into VMware Workstation Pro. It worked seemlessly. In case you’re interested in how the performance with a Hackintosh VM is, you can read my Blog Post here.

1.Download Big Sur via the AppStore on your Mac

2. Open a terminal window and type in the following commands:

sudo hdiutil create -o /tmp/BigSur -size 16384m -volname BigSur -layout SPUD -fs HFS+J

sudo hdiutil attach /tmp/BigSur.dmg -noverify -mountpoint /Volumes/BigSur

sudo /Applications/Install\ macOS\ Big\
Sur.app/Contents/Resources/createinstallmedia --volume /Volumes/BigSur --nointeraction

hdiutil eject -force /Volumes/Install\ macOS\ Big\ Sur

hdiutil convert /tmp/BigSur.dmg -format UDTO -o ~/Desktop/BigSur

mv -v ~/Desktop/BigSur.cdr ~/Desktop/BigSur.iso

sudo rm -fv /tmp/BigSur.dmg

Now you should have the Big Sur Iso file on your desktop, mine is about 17 GB large.