The Composite file system was introduced into Windows 10 Build 2004. One big difference between CIMFS and the Virtual Disk (VHD and VHDX) is that CIMFS does not show in both the Device Manager and Disk Management consoles. This makes it more tricky to diagnose issues or clear mounted CIM images.
You will also note that the command line prompt “mountvol” does not really help in a large scale production environment as it only shows the volume guid, no further information.
How to Identify CIMFS Mountpoints
To make things easy, I have created a simple script that helps you visualise the different file system types against a mountpoint.
As you can see from the screenshot below, you can see that the script outputs the different filesystem types, identifying which.
I have also written a PowerShell module complied as an MSI for an easy install. Once installed, all you need to do is run the cmdlet get-mountpoints, which will, in turn, then output all the different file system types.
You can download the PowerShell module here:
You can also output specifically CIMFS mounted images by using the following PowerShell Script.
The mountpoint script helps identify the mountpoints associated with CIMFS. This will help if you need to troubleshoot or unmount a CIMFS image. You can also use the free community tool I created to unmount CIMFS images, link provided here: MSIX_APP_ATTACH/Cimfs tool/Cimutil installer at master · RMITBLOG/MSIX_APP_ATTACH (github.com)