In this tutorial we will describe how to install Virtualbox Guest additions on Fedora Linux virtual machine. The rule of thumb here is that the most recent Fedora Linux version requires up to date Vitualbox installation. Having said that, it is possible to install Virtualbox Guest additions for most recent Fedora Linux using outdated Virtualbox installation, however the process would not be that straight forward. Therefore, if possible, before you continue to read, see what version of Virtualbox you are running and compare it with the version found on the official Virtualbox website. The more recent VirtualBox version the less likely you are to run into X server version incompatibility and to get error:

"unknown X server version"

Apart of the updated Virtualbox version this guide also assumes functional Fedora Linux installation with working Internet connection. Lastly, the aim here is to provide a generic guide for Virtualbox Guest additions on Fedora Linux virtual machine and as a result reader needs to adjust some of the following commands to is your envireoment.

Step 1: Mount Guest additions

Start your Fedora virtual machine and mount Virtualbox Guest additions by navigating to Virtual box menu -> Devices -> Insert Guest Additions CD image The following message will pop up:
Hit cancel and navigate to Virtualbox Guest additions mounted directory using your terminal:

# mount | grep -i vbox
/dev/sr0 on /run/media/fedora/VBOXADDITIONS_VERSION type iso9660
# cd /run/media/fedora/VBOXADDITIONS_VERSION
# ls
32Bit  AUTORUN.INF  cert  runasroot.sh            VBoxSolarisAdditions.pkg        VBoxWindowsAdditions.exe
64Bit  autorun.sh   OS2   VBoxLinuxAdditions.run  VBoxWindowsAdditions-amd64.exe  VBoxWindowsAdditions-x86.exe

Step 2: Install pre-requisites

Now that we have our guest additions we need to install development tools which a prerequisites for successful Virtualbox Guest additions modules compilation. There is one thing to keep in mind when before the running the following command. The Virtualbox Guest additions modules compilation will be done against your currently running kernel. This simply means that with every kernel update you will need to install appropriate version of kernel headers and recompile Virtualbox Guest additions modules.

yum install kernel-devel-$(uname -r) kernel-headers-$(uname -r) gcc

Step 3: Install and compile Virtualbox Guest additions

At this stage we are ready to install Virtualbox Guest additions. Still in the Virtualbox Guest additions directory execute VBoxLinuxAdditions.run script:

# ./VBoxLinuxAdditions.run
Verifying archive integrity... All good.
Uncompressing VirtualBox 4.3.12 Guest Additions for Linux............
VirtualBox Guest Additions installer
Removing installed version 4.3.12 of VirtualBox Guest Additions...
Copying additional installer modules ...
Installing additional modules ...
Building the VirtualBox Guest Additions kernel modules
Building the main Guest Additions module                   [  OK  ]
Building the shared folder support module                  [  OK  ]
Building the OpenGL support module                         [  OK  ]
Doing non-kernel setup of the Guest Additions              [  OK  ]
Starting the VirtualBox Guest Additions                    [  OK  ]
Installing the Window System drivers
Installing X.Org Server 1.14 modules                       [  OK  ]
Setting up the Window System to use the Guest Additions    [  OK  ]
You may need to restart the hal service and the Window System (or just restart
the guest system) to enable the Guest Additions.

Installing graphics libraries and desktop services component[  OK  ]

All is now ready to reboot your system for VirtualBox Guest Additions to take effect. If you installation fails from some reason make sure to read /var/log/vboxadd-install.log for additional information the help you resolve your problem.