Re: [tlug] how filesystem works?

["Stephen J. Turnbull" <stephen@example.com>]

Attila Kinali writes:

 > There is no defrag for unix file systems. Unix filesystems are
 > so called self defragmenting. Ok, the term is IMHO missued here,
 > (it should be "fragmentation avoiding") but it shows the visible
 > effect: no defragmentation needed.

Actually, there are defrags for Unix file systems (eg, for HFS+, but I
digress ;-), which are specifically designed for the purpose of making
it safe to resize partitions.  They're more hazardous than it's worth,
though.  Nobody feels the need, so nobody uses them, nobody debugs
them, and they stay dangerous.

 > No, mv doesn't know anything about the filesystem. Only that it's moving
 > files around. And mind you as long as you move the file within the same
 > partition, you will not move the data around but only the reference to
 > the data.

Actually, IMO it's better to think in terms of "mv == rename" first,
with a special extension for the case where renaming is not possible
(different file systems).  This clear up a lot of confusion about mv
for many newbies.  It's a shame there's not a similar intuition for
rm.

As any Japanese knows, there are very few problems that cannot be
dealt with by a sufficient amount of indirection. :-)