neil@causality.com (Neil A. Carson) writes:

>...and, of course, defragmenting FFS isn't anywhere near as easy as
>other filing systems that defragment (ADFS, FAT) because there is no
>data structure descibing a physical->logical mapping of the blocks on
>the disc (the i-node goes the other way).

However, there is a data structure describing the logical->physical mapping
of the blocks on the disk and since the mapping is a one-to-one mapping,
this is good enough.

In fact, there's a defragmenter for V7 filesystems floating around in the
comp.sources.unix archives that I have used with no problems several times
in my Xenix days.

-- 
Christoph Badura					www.netbsd.org

	Anything that can be done in O(N) can be done in O(N^2).
	-- Ralf Schuettau (after looking at a particular piece of code)