Does "Panther has automatic defragging" ?

[hype.it]

While we're talking about the not so well known/hidden new Panther
features: while digging through the kernel sources i've found a quite
amusing new feature built into HFS+. Namely automatic file
defragmentation.


Everytime an application opens a file for reading, HFS+ checks if the
file is fragmented and is less than 20MB in size. If so, it copies the
file's contents to a continuous region on the disk and frees up the
previously allocated blocks.

Interesting topic... does anyone here have any proof on this matter?

http://episteme.arstechnica.com/eve/ubb.x?q=Y&a=tpc&s=50009562&f=8300945231&m=9900929295&p=1

 

[trpnmonkey41]

well.....everytime you install something such as a System Update file it always does "Optimizing Macintosh HD" which is essentially defragging it.

I have never seen anything about defragging everytime you open something but it does make perfect sense because it is only checking the file you are opening not the whole system

 

[rman]

I know in Sun OS it does a defrag on boot up. In sgi's IRIX it does the defrag once a week early Sunday morning.

Mac OS X do it on boot up also, but I am not sure. Due to the amount of time it takes sometime to optimize after installing an update, does make since.

 

[witeshark]

What I have heard is the Mac and lately Linux has a by file defrag. And I notice my Mac recovering disk space on log off after heavy net surfing