Make sure you have installed the guest additions on the guest system.
Definition of the shared folder
Go to the Oracle VM VirtualBox Manager, right-click on the machine and choose Settings.
Create a shared folder in the wizard. Remember the "name" of the folder, in this example SHAREDFOLDERNAME.
If you check "Automount on boot" when defining the shared folder, simply reboot the system and you will find it here: /media/sf_SHAREDFOLDERNAME
Or mount the folder manually
root@testkraxn / # cd /media root@testkraxn /media # mkdir sharedfolder root@testkraxn /media # mount -t vboxsf SHAREDFOLDERNAME sharedfolder
Note, I stumbled over this: You need to close the "Add shared folder" wizard in the VBox Manager gui to be able to mount the folder.
Access shared folder with other users
You may want to allow some users to access this dir, so add them to the vboxsf group:
root@testkraxn /media/cdrom # usermod -a -G vboxsf tester root@testkraxn /media # groups tester tester : tester adm cdrom sudo dip plugdev lpadmin sambashare vboxsf