Host volume mapping is a folder shared between the host and the VM?
Yes.
Hosts:
Notebook runs Linux Mint 17 with VirtualBox 5.0
Desktop runs Windows 7 with VirtualBox 4.3 (5.0 ha an issue on Win7 that Oracle won't fix, but prevent my VM from starting)
Guest:
Xubuntu 15.04 with the VirtualBox 5.0 Guest Additions