To share a folder using the following procedure, the OS-specific guest additions package must be pre-installed. You can set up NFS or Samba to share a folder between a Linux host and a FreeBSD guest. The method outlined in this blog post works for Linux and Windows guest OSes but not FreeBSD. Part 3 shows how the guest OS can access USB drives mounted on the host. Part 2 outlines the post installation tasks, including installing the universal VirtualBox extension pack. Part 1 of the series shows how to install VirtualBox on a Debian host, and how to create a FreeBSD virtual machine. The focus is on how to share folders between the host and the guest OSes. This post is the 4th installment of the VirtualBox series.