Re: huh?
Originally posted by zimv20
please explain that to me.
here's my understanding: (file) fragmentation is the scattering of a single file to multiple sections of a drive. when the file is needed, those parts must be reassembled.
the drive head MUST move to each of those sections. however quickly that head moves, it takes time. w/ badly fragmented drives, that time adds up.
also consider the additional amount of time it takes the OS to write a file to fragemented drive -- it must go out and find enough chunks (using whatever optimization scheme is built in) so that file can be saved.
i defrag often -- several times a month. i use TechTools Pro and have never had a problem.
my advice is to defrag.
Well, I can't expain it, as I'm going off of what I've been told, and read, which has lacked in technical details. However, If you'd like to google it, I would suggest searching for 'unix defragmentation tools', 'ufs fragmentation', etc.
Let us know what you discover!
It could be that UFS habitually cleans its mess in the background, it could have to do with write allocation methodologies, but whatever causes it, I'm pretty sure that defragmentation is just not part of the UNIX world. I have a friend who runs a large number of Solaris boxes, and has for over 10 years, and has never once defragged them (although he does his Windows box religiously). Much of this has to do with file system type (hfs+, NTFS, UFS, ext2, reiser, etc.) as well as the OS, and I do not think the research regarding OSX is really in yet.
Additionally, I'd be very wary of the current tools for OSX. Many of them have been kludged together quickly in order to retain mindshare/market-share, and as such, are notoriuosly dangerous (google a few searches and you'll see what I mean!).
If you're having good luck, and seeing a speed up, more power to you, but I'm going to wait until I feel a defrag is necessary (if ever), before risking one.
To cb911: doing video on a laptop drive is often going to choke things, as the OS, the video, and the swap, are all on the same logical device. If you're concerned, I'd say your better off buying a FireWire external than a bunch of immature sw tools.
[edit]
Finding links, of which there are few:
http://cbbrowne.com/info/defrag.html
http://www.macslash.org/articles/02/08/01/1829246.shtml (loadsa of good info here, but you must read it ALL)
http://www.applelinks.com/articles/2002/04/20020402131036.shtml
http://www.macintouch.com/fragmentation.html
It appears that:
UFS defrags itself
ext2, ext2fs, and reiser do not suffer measurable slowdowns from fragmentation
HFS+ is suceptible to fragmentation, but under OSX appears to be resiliant to it, and success/failures based on defragging are 50%/50%
HFS+ under OS9 is likely to benefit from defragmentation
NTFS, FAT32, and FAT show great benefits from defragging
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