How to block the macOS Big Sur installer

Introduction

If your organization is not ready to support Macs running macOS Big Sur, you may prevent the upgrade of the managed Macs to Big Sur. This article provides step-by-step instructions on how to block the installation of macOS 11 Big Sur. Later, when ready, you will need to remove the blocking package to allow the upgrade to Big Sur.

Installing the macOS Big Sur Blocker

The macOS Big Sur Blocker is a system agent that monitors running processes. If the process startup path contains the string "Install macOS Big Sur.app" then the agent terminates that process.

Create a Software Package to install the macOS Big Sur Blocker

1. Download the attached BigSurBlocker.zip archive and unzip it to a dedicated folder.
2. In the SCCM Console, navigate to \Software Library\Overview\Application Management\Packages.
3. Choose the Create Package action. A wizard will open.
4. On the Package page, enter the Name, select the This package contains source files checkbox, and specify the Source folder path using the Browse... button to the folder from step 1 (above).
   
    
5. On the Program Type page, select the Standard Program type.
   
   
    
6. On the Standard Program page, enter the Name and Command line.
   
   
7. On the Requirements page, click Next.
   
   
   
    
8. On the Summary page, click Next.
   
   
   
    
9. On the Completion page, click Close.
   
   
    

Deploy the package

1. Select the package created in the previous step.
2. Choose the Deploy action. The Deploy Software Wizard opens.
3. On the General page, select a collection of Macs using the Browse... button.
   
   
    
4. On the Content page, add Distribution points to distribute the content to.
   
   
   
   
    
5. On the Deployment Settings page, click Next.
   
   
   
    
6. On the Scheduling page, create a new As soon as possible schedule using the New... button.
   
   
    
7. On the User Experience page, click Next.
   
   
   
    
8. On the Distribution Points page, click Next.
   
   
    
9. On the Summary page, click Next.
   
   
   
    
10. On the Completion page, click Close.
    
    
    
     

Uninstalling the macOS Big Sur Blocker

1. In the SCCM Console, navigate to \Software Library\Overview\Application Management\Packages.
2. Select the Big Sur Blocker package created in previous steps.
3. Switch to the Deployments tab in the Details pane at the bottom of the window. Remove deployment of the Install program.
4. Choose the Create Program action for the Big Sur Blocker package from the Ribbon bar or the right-click menu. The Create Program Wizard opens.
5. On the Program Type page, select the Standard Program type.
6. On the Standard Program page, enter the Name and Command line.
   
   
   
    
7. On the Requirements page, click Next.
8. On the Summary page, click Next.
9. On the Completion page, click Close.
10. Switch to the Programs tab in the Details pane at the bottom of the window. Select the Uninstall program.
11. Choose the Deploy action and configure the deployment the same way as for the Install program from the steps above.