Re: cachefs on linux

> Anyway, linux also does not have unionFS. If it was that big of a deal,
> someone would write it. As it is, it's a whizbang no one cares about enough.

BSD has had a UnionFS for a while now, by the way.

There are a lot of things we _could_ add to filesystems, E.G.:

* Appending to a read-only filesystem on a separate volume

* File versioning

* Transparent, variable compression

* Format conversion, (I.E. write a png file to a filesystem, and it is
			   automatically visible as half a dozen other
			   formats, without them actually existing on
			   the disk)

* Priorities, (E.G. temp files could have a bit to indicate that we
		    don't really care how long they remain in
		    write-cache, instead of flushing them along with
		    other more-important-to-get-to-the-oxide data)

* WORM mode, (I.E. start at block 1 and use blocks sequentially, never
		   re-using blocks - makes a tape somewhat usable as a
		   block device)

Some of these are available in some form or another already.  There is
plenty we can do, given enough time :-).

John.