Does the Mac filesystem need defragmeting?
 

I know there are defrag apps for classic OS, and I know the filesystem is the same in X (they both share a partition!) so that leads me to think that i might need to defragment my hard disk.

Are they any OSX apps, any free ones? Do Macs need defraging? I know my Windows NTFS partition does, what about Macs?

I'm not aware of any free defragmenters. Micromat and Norton both make defrag products that will work with OS X drives, since they're just HFS+ (but double-check their websites to be sure).

In 15+ years of using my Mac, including 1.5 with OS X, I've yet to defrag a drive. If I had less RAM, maybe I'd notice a problem, but my machine certainly seems just as peppy as it's ever been.

-rob.

Thanks for the reply. One of the things that would be cool would be if you could have other file systems on X like SGI's XFS (i think thats what it's called) which doesn't need defragmenting or error checking if you don't shutdown prop

Marc

Mmm, I think you should check again. Before I swithed to MacOS X I used to defrag on a regular basis, using Norton. Saves a lot of trouble. Now the OS is different, but the fs is the same. I think we do need some defragging soft for MacOS X

Hopefully it will be free and won't require a restarting, although a commandline based on that runs in single user mode would be a good option to make sure the disk isn't be used much.

heeey!
what about iPod? it's got an HFS (or HFS+) partition, how about a defragmenting tool for it! thats an idea for commercial soft, imagine "structures all your playlists for better playback" on the sticker

LOL! They could charge a packet for it as well.

i personally think you spend more time opening the application and clicking yes/no to all the "shall i fix it?" than you would actually save in the long run, and the unmounting/cpu usage also costs you.

There is a Couple of free Defragmenters/ Prebinding programs
 

Try going to Versiontracker. There is a program called XOptimize that works pretty well and it's free. You should still run Norton and Diskwarrior to optimize your drive to see any real speed in OS X

thanks for that, XOptimize looks good.

Just to clarify, XOptimize is in no way a disk defragger. It's merely a front end to the Terminal command:

sudo update prebinding -root /

This command simply helps OS X launch applications faster. It doesn't physically move anything around on your hard drive. It simply pre-binds (hence the name) the libraries that the application needs to load at runtime, so that when launched, the application doesn't have to go looking for them.

This is a much different beast than a disk defragmetation program, and it is something that I do regularly.

-rob.

Do you have to do it each time you start your mac, or just once?

You never have to update the prebinding - it's done automatically by many installers (the Optimizing System Performance step), and applications won't fail if it's not done. Just a little bit of preventative maintenance, it's good to do after you install a bunch of programs just to optimize a little.

so what about defragging, then? I was told that UNIX does all that upkeep on it's own, while the system is running, which is why there's no defrag app in the system utilities, but I've never had it confirmed...

Defragmenting is putting all the data on a disk together, over time data gets scatterd, so it takes longer to applications to start, and for large documents to open.

Defragmenting moves the data into one place on a disk, Unix doesn't do this unless you have a filesystem that can, the Mac OS filesystem can't.

Windows includes a defragmentor, see http://members.aol.com/marcwic/defrag.jpg

I read somewhere that the unix answer to defragmentation is to ensure as much as possible that the fragments are on the same sector or cylinder or whatever to ensure that the drive doesn't have to zip all over the surface of the disk to find the different fragments. Ok, so you can tell that I don't really know what I'm talking about, but it sort of made sense at the time... And I guess that's why Norton didn't include a defragmentation utility in Norton Utilities 7.0. Incidentally, the only time I ever noticed a difference was in previous OSs when the system was scattered all over the place - starting up did seem much faster when it was defragmented.

As I understand it, some unix OS's have a built in defragmentation program that kicks in if the disk is more than 3% or so fragmented. This is not, however, universal and Darwin doesn't have it.

As for the need to defragment, I have only anectdotal evidence that it can help. I checked my OS X partition with Norton Utilities 6.0 (booted into OS 9 partition). It was terribly fragmented. The worst I'd ever seen. It was slow to open programs and microsoft word would "lose the connection" to large files. (An actual error I gort when opening 2 MB or so documents.) If you opened the doc and immediately scrolled down, it would disconnect from the document.

I used NU 6.0 to defragment, but did not use disk doctor...I used the disk first aid to diagnose and repair the partition. After defragmentation, I noticed a marked improvement in responsiveness and the disconnecting document problem went away.

While this is not proof that the defragmentation really did it, it's enough for me to believe it had something to do with the performance boost.

I'm still very weary of Norton in OS X as I've heard a number of bad things...but it's what I had, and I had a back up.

I hope that help

I have never degragged a mac volume but it does always speed up my windows machine running NTFS.

I don't think we should have to pay for a defragmenter! Should come free.

MW

Have a read at This thread

/ * Begin my two cents

The consensus seems to be that OS X "wildly fragments" the hard disk upon installation, and that things stay that way until you boot into OS 9 and "fix" things.

My gut reaction is the good old "OS X is not OS 9, dammit!" :)

I suspect that OS X is quite happy dealing with a "fragmented" drive. The idea that it's a bad thing may fall apart with today's high-speed drives. Also, by scattering data over the whole surface of a drive, and using the "Prebinding" optimisation to locate and flag oft-used files, I suspect you may actually achieve a performance boost, as the drive head will always be statistically the same distance from any file.

However, I could be talking out of my ass. People seem to be reporting performance boosts by defragging their OS X drive from OS 9, but I'm wary of condoning that. Once again, OS X is not OS 9, and this sort of cavalier attitude to doing things the OS 9 way could be problematic further down the line. Bear in mind that OS 9 doesn't use prebinding, so clumping all the files together will help there, but could break OS X in some way.

Also, if it gives THAT much of a performance boost, why aren't Apple publicising it? They've been criticised over OS X's performance, so you'd think a quick fix like this would be high in their knowledge base. As such, a search there for "defrag" doesn't pick up any articles newer than y2k, and they're all concerned with OS 9.

End my two cents */

Has anyone found Apple's line on defragmenting?

The problem if when one file is spilt around a disk, this will always cause a slow down. I am supprised apple haven't included a defragmentor in X, there should have been one in OS9, it's not the type if thing you expect to have to pay for!

I was hoping maybe someone could port a Linux one, but as far as I know the Linux FS (EXT2 i think it's called) defragments as it read/writes or something like that... so they're aren't any Linix defragmentors..!