I managed to install FreeBSD and OpenBSD under VirtualBox. With NetBSD I gave up :-(. Here are some tips:
- This is a good general OpenBSD tutorial
- If you get the following message with OpenBSD:
uid 0 on /: file system full /: write failed, file system is full Segmentation fault
The solution described by this VB ticket might help you. Specifically you need run the machine from the command line with the -noraw0 switch.
- For FreeBSD choose the PCne-PCI II network card (instead of III) and 10BaseT as your media type if you want your networking to work
- A quick starter for NetBSD: it fails to ping the DNS server in NAT mode (10.0.2.3), but the network still works, so you can go ahead with the install.