If you have a dual-boot system with Bazzite and Windows 11 installed, keeping two separate Steam libraries gets pretty frustrating. This is where a shared BTRFS partition makes a lot of sense, as it lets both operating systems access the same game files, saving both storage space and download time. So follow along as this guide shows you how to create a dedicated BTRFS partition, configure Windows with the WinBTRFS driver, and set the correct permissions so both operating systems can access the files properly.

Takeaways:

  1. How do you create a shared BTRFS Steam library between Bazzite and Windows 11
  2. Is there a way to make a shared partition for Bazzite and Windows for games?

How to Create a Shared BTRFS Steam Library Between Bazzite and Windows 11

Before you start anything below, make sure you have backed up anything important. Resizing partitions always carries a small risk of data loss if something goes wrong.

Create the Shared BTRFS Partition

Boot into a GParted Live USB.

Using GParted:

  • Shrink your existing Bazzite partition to free up space.

Create a Shared BTRFS Steam Library Between Bazzite and Windows 11

  • Create a new partition in the unallocated space.
  • Format the new partition as BTRFS.

How to Create a Shared BTRFS Steam Library Between Bazzite and Windows 11

  • Apply the pending operations and wait for them to complete.

How to Create a Shared BTRFS Steam Library Between Bazzite and Windows

  • Once finished, reboot into Windows.

Install WinBTRFS

Search for WinBTRFS and download the latest release from its GitHub project.

Extract the ZIP archive, then:

  • Right-click btrfs.inf.
  • Select Install.
  • Confirm the installation.

If your new BTRFS drive does not appear, Secure Boot is most likely preventing the driver from loading.

Secure Boot Workaround

If Secure Boot is disabled, you can skip this section.

  • Open Registry Editor and Go to:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\CI\Policy

  • Create a new DWORD named:
  • UpgradedSystem
  • Set its value to: 1
  • Restart Windows.
  • After rebooting, your BTRFS partitions should now be visible.

Create a Shared BTRFS Steam Library Between Bazzite and Windows 11

Configure WinBTRFS Permissions

By default, files created in Windows may not be writable from Bazzite without elevated permissions. We can fix that by matching the Linux user and group IDs.

  • Open Command Prompt and run:

whoami /user

Create a Shared BTRFS Steam Library Between Bazzite and Windows

  • Copy the SID displayed for your account.
  • Open Registry Editor and go to:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\btrfs\Mappings

  • Create a new DWORD using your SID as the name and assign it a Decimal value of: 1000

Shared BTRFS Steam Library Between Bazzite and Windows 11

  • Repeat the same process inside: GroupMappings
  • Again, create a DWORD named after your SID and set the decimal value to: 1000

Shared BTRFS Steam Library Between Bazzite and Windows

  • Finally, update the remaining default mapping entry to 1000 as well. This makes sure files created by Windows services are also accessible from Bazzite.

Hide Your Bazzite System Partition

To avoid accidentally modifying your Linux installation from Windows, hide the Bazzite partition.

  • Right-click the Bazzite drive, open Properties, switch to the BTRFS tab, and note its UUID.

Guide to Create a Shared BTRFS Steam Library Between Bazzite and Windows 11

  • Open Registry Editor and locate the registry key for that partition.
  • Create a DWORD named: Ignore
  • Set its value to: 1

Steps Create a Shared BTRFS Steam Library Between Bazzite and Windows 11

  • Restart Windows.
  • After rebooting, the Bazzite system partition should no longer appear in File Explorer, while your shared Games partition remains accessible.

Configure Steam in Windows

  • Open Steam and go to: Settings > Storage
  • Add your new BTRFS Games drive and make it the default installation location.
  • Install a game to verify everything is working correctly.
  • After installation, check the BTRFS properties for the files. Both the User and Group values should be 1000.
  • If they are not, return to the registry and confirm the values were entered as Decimal, not Hexadecimal.

Configure Automatic Mounting in Bazzite

  • Boot into Bazzite.
  • First, create a mount point:

sudo mkdir /var/mnt/games

How to Create a Shared BTRFS Steam Library Between Bazzite and Windows 11 process

  • Next, open KDE Partition Manager.
  • Right-click the Games partition and choose Edit Mount Point.
  • Configure the following:

Mount Point

  • Use UUID
  • Mount path: /var/mnt/games
  • Clear all optional checkboxes

How to Create a Shared BTRFS Steam Library Between Bazzite and Windows 11 steps

  • Select More and paste in the recommended BTRFS mount options from the Bazzite documentation on the Bazzite website.
  • Save the changes when prompted.

How to Create a Shared BTRFS Steam Library Between Bazzite and Windows 11 step

KDE Partition Manager will update your fstab file automatically. Run the verification command provided in the Bazzite documentation. If the command produces no output, your configuration is correct.

Fix Folder Permissions

If you cannot create files inside the mounted partition, run:

sudo chown $USER:$USER /var/mnt/games

shared drive for bazzite and windows

After entering your password, verify in Dolphin that you can now create folders and files normally.

Configure Steam in Bazzite

  • Open Steam and go to: Settings > Storage

Add: /var/mnt/games

  • Select it as your default Steam library.

If everything has been configured correctly, Steam should immediately detect the game that was installed from Windows without needing to download it again.