For installation instructions, see
If you configure a cpu server (Configuring a standalone CPU server), you can run it from a terminal by adding a line
console=0to plan9.ini and invoking the virtual machine with option -nographic. Note that you need to configure Qemu networking to allow connections to the virtual machine.
Note that <Del> is <fn>+<Bksp>. You can use vncv to connect to the host OS X using fast user switching, see http://www.redstonesoftware.com/multidesktop.html.
Under Virtual Box 3.0, selecting the ICH6 chipset rather than PIIX3 or PIIX4, and deselecting all disks allows 9pccpu to run. AMD79C970 Ethernet PXE boots reliably but the Intel Ethernet emulations don't.