Something I've wonderd about for a while:  why does NetBSD have both
mfs and a ram-disk driver?   It seems somewhat redundant. Is the 
ramdisk necessary for booting on some ports?  If so, what's the
advantage of mfs over an ffs filesystem on a ramdisk?

(I'm not saying there *isn't* some  advantage to having both, I'm
 just curious to hear what it is.)