Create a Shared Folder

In this section, you create a folder that is shared between your host machine and your virtual machine. Anything you create or place in this shared folder will be accessible on both host and virtual machines.

1. Create a folder somewhere on your host machine that you want to contain the shared documents.

2. Open Virtual Box.

3. Ensure the machine is not in a running state or saved state (i.e. it should be shut down).

4. Click the settings icon and complete the following:

   1. Navigate to Shared Folders in the settings menu.

   2. Find the plus (+) icon to add a folder.

   3. For the Folder Path option, browse the host and select the folder you want to be the shared folder.

   4. For the Folder Name option, you can name it what you want. This name will be the name it has on the virtual machine. For the purposes of this tutorial, we will name it SHARED.

   5. Check the Auto Mount option.

   6. Check the Make Permanent option.

   7. Click OK to confirm the folder options.

   8. Click OK to confirm the new settings. If you get an error at this point, it may be that your machine is in a running or saved state. If so, cancel any changes and shutdown the machine.

5. Boot the virtual machine.

6. Open a terminal.

7. Install guest additions with the following commands.

   sudo apt update

   sudo apt install -y build-essential dkms linux-headers-$(uname -r)

8. On the host machine, find the Virtual Box menu named Devices. This is in the same menu bar as File, Edit, … at the top of the window on Windows or at the top of screen on a Mac.

9. Open the Devices menu and select Insert Guest Additions CD image.... After clicking it, you should see a CD Rom icon appear as a device on the VM (in the dock on Ubuntu, or on the left in the file browser application).

10. On the Virtual Machine, run the following commands to finish the setup. Be sure to run the appropriate command based on the architecture of your machine

    sudo mount /dev/cdrom /mnt

    # On ARM machines
    sudo /mnt/VBoxLinuxAdditions-arm64.run
    
    # On x86 machines
    sudo /mnt/VBoxLinuxAdditions.run

11. Restart the virtual machine. You can just choose to reboot from within the machine, or restart with virtual box.

12. Log back in and add the current user to the vboxsf group by running the following command.

    sudo usermod -aG vboxsf $USER 

13. Reboot one last time so that the group permissions are applied.

14. The shared folder should be located at /media/sf_SHARED where SHARED is the name given to the folder previously.

15. If you open a folder, with the file browser app (the app with the folder icon) you should see the shared folder in the navigation on the left hand side.

16. Test the shared folder by adding files to it on your host machine and viewing the files from the virtual machine. Also, try the reverse.