> If / is the only thingee that is read only, > I don't think that buys anything worthwhile.
It's one less fsck needed after an unclean shutdown, if nothing else.. This can be quite useful on boxes with unreliable power if you know you don't need to write to the partition. It also helps keep your kernels and boot loader intact, increasing chances of doing something useful with the box afterwards, especially helpful if it's remote-hosted, you have a serial console setup in boot.conf, and you don't have easy access to the physical machine. btw: it's necessary to modify /etc/rc to mount / RO.
