Existe outro wiki encontrado nos resultados do Google:
Verbatim da fonte :
NOTE: VirtualBox is not a very good choice. Behavior changes dramatically from release to release, with some working out of the box, some needing just the right settings, and some not working at all. You are highly encouraged to pick a different VM. VMware, qemu (with or without kqemu), kvm, and xen are all known to work better.
Veja também: instalando o plano 9 no qemu , em xen , no xen 3.0 .
Bell Labs' Plan 9 and networking works well in virtualbox 3.1.8 using Am79C973 virtual ethernet adapter in bridged mode, chipset PIIX3 selected and "Enable IO APIC" turned off.
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.