raw disk file hacks

[utzoo!decvax!ucbvax!Greg at NPRDC]

From: Greg at NPRDC
I have a driver that allows you to collect disk pieces into a single
conceptual filesystem.  It's not dynamic, but one could concieve of
a program that opened /dev/kmem and modified it.  This one was designed
to permit us to put the first part of our swap on a fast device and
any overflow onto a larger device, so as not to panic when the smaller,
faster space was used up, which happens occasionally.  This allows us
to put both our /tmp and swap on a fast device.  You're welcome to it
if you wish; it would make a good starting point.