Once the creation process finishes, unmount the volume safely: hdiutil detach /Volumes/Install\ macOS\ Big\ Sur Use code with caution. Step 7: Convert the DMG File to ISO Format
Installing an older, stable version of Big Sur (such as 11.6, a common 2021 stable release) rather than the newest macOS. Prerequisites for Creating a Big Sur ISO To create a valid, functional ISO file, you will need:
What are you using? (VirtualBox, VMware, Parallels, etc.)
In 2021, Apple solidified macOS Big Sur (version 11) as the foundational operating system for the transition to Apple Silicon (M1) chips while providing substantial updates to Intel-based Macs. It introduced a major design overhaul, Safari enhancements, and new privacy features. macos big sur iso 2021
Creating a bootable USB drive to update multiple Macs without downloading the package each time.
IT administrators can use the ISO to deploy the operating system across multiple machines without consuming internet bandwidth for every individual download. Technical Specifications of macOS Big Sur (2021)
Many third-party websites offer direct download links for macOS Big Sur ISO files. While tempting, downloading pre-made ISOs from untrusted sources poses severe security risks: Once the creation process finishes, unmount the volume
Here is a simplified breakdown of the process to create a macOS Big Sur ISO on a Mac:
The final installer typically ranges between 12 GB and 13.5 GB .
For the most reliable and clean ISO, it is recommended to create it yourself from Apple's official files on a compatible Mac. Here are the steps: (VirtualBox, VMware, Parallels, etc
Select "Apple Mac OS X" and set the version to macOS 11.1 or higher.
VirtualBox requires you to spoof Apple hardware parameters via the Windows Command Prompt (run as Admin) before launching the VM: