Boot a kernel with a MFS in it with a special /sbin/init
which...
C: as /C:C:/freebsd.fs on /dev/vn0/dev/vn0 as /rootfs/rootfs/bin -> /bin/rootfs/etc -> /etc/rootfs/sbin -> /sbinNow you are running FreeBSD without repartitioning your hard disk...
NFS mounts your server:~you/FreeBSD as
/nfs, chroots to /nfs and executes
/sbin/init there
Now you are running FreeBSD diskless, even though you do not control the NFS server...
Now you have an X-terminal, which is better than that dingy X-under-windows-so-slow-you-can-see-what-it-does thing that your boss insist is better than forking out money on hardware.
Takes a copy of /dev/rwd0 and writes it to a remote tape
station or fileserver.
Now you finally get that backup you should have made a year ago...
This is particularly interesting since you can boot from a write- protected floppy, but still write to your root filesystem...