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Curiosity · Jul 16, 2006, 01:10 AM

Is there any disk defragmenter application for Macintosh? What do people do when files are not in one piece any more? Are fragmented files a problem?

kick52 · Jul 16, 2006, 02:58 AM

no, os x automaticly defrags small files, and you wouldnt notice any difference if you did defrag.

when files are "not in one piece anymore" it means that the data is spred out on th HD rather than in one block. if os x hasnt corrected this, you wont notice much slowdown and it doesnt mean you see several files on your desktop that are different parts of one file.

dont worry about it.

MacMatt · Jul 16, 2006, 10:05 AM

MicroMat's TechTool Pro. Defragments, rebuilds Directories, plus other maintenance functions.

Curiosity · Jul 16, 2006, 12:57 PM

I just picked up Techtool Pro. Thanks, guys.

real · Jul 17, 2006, 12:23 PM

I have done defrags and it seems to me that is make it slower.

I base that on when you reboot after system upgrades, or whatever you system feels snapper.

I have no proof that it slows you down but it seems like it does.

real

TETENAL · Jul 17, 2006, 12:39 PM

Originally Posted by Curiosity

I just picked up Techtool Pro.

Even though you learned that the system automatically defrags on its own?

Tomchu · Jul 17, 2006, 01:32 PM

Ahh, the age-old question, and the age-old misconceptions that follow ...

1. OS X only defragments certain files when very specific conditions are met.

2. All file systems suffer from fragmentation to some extent or another. There's very little that HFS+ can do about a huge file (say raw video) becoming fragmented on a drive that's 70%+ full.

3. Defragmenting a drive will never slow it down. If OS X takes ages to reboot after doing something of the sort, that's simply because your caches were purged and have to be rebuilt. An hour of use and a few reboots are all that's required to get all of that rebuilt.

4. Defragmenting is not evil, and will not result in data loss if you use a non-shoddy utility.

tooki · Jul 17, 2006, 01:59 PM

I tend to agree with the disk experts, who say that the risk, and the time required to defragment safely, outweigh any possible minute improvements one might reap.

http://db.tidbits.com/getbits.acgi?tbart=07254

The salient points are that:
1. the potential speedup is usually negligible
2. to defragment safely, one must first make a full backup, in case something goes wrong -- but if you have the backup, you could just copy it back and it would be defragmented!

Sure, in some situations, like HD video, it might help. But modern hard disks are so fast that the time savings are negligible, and the time taken to defragment is FAR more than the time saved.

tooki

Tomchu · Jul 19, 2006, 01:26 PM

On a rather full hard drive, a huge file can be fragmented into thousands of pieces -- and you'll definitely feel the impact there.

Anyway, clearly the "disk experts" haven't heard of Diskeeper on Windows. It does live, on-the-fly defragmentation while you work, and I have yet to ever suffer from data corruption with it -- nor have the many people I've talked to who use it. Where there's a will, there's a way.

I'm willing to bet that OS X simply doesn't have the facilities to allow live defragmentation safely.

analogika · Jul 19, 2006, 03:09 PM

Originally Posted by Tomchu

On a rather full hard drive, a huge file can be fragmented into thousands of pieces -- and you'll definitely feel the impact there.

Anyway, clearly the "disk experts" haven't heard of Diskeeper on Windows. It does live, on-the-fly defragmentation while you work, and I have yet to ever suffer from data corruption with it -- nor have the many people I've talked to who use it. Where there's a will, there's a way.

I'm willing to bet that OS X simply doesn't have the facilities to allow live defragmentation safely.

Actually, OS X DOES live defragmentation - safely.

tooki · Jul 20, 2006, 10:58 AM

Yup.

And what it does takes care of pretty much all the optimization an OS X disk needs.

tooki

Tomchu · Jul 20, 2006, 02:29 PM

Live defragmentation in the style of Diskeeper? Not quite.

In any case, there are facts, and then there is firmly-rooted, but incorrect, beliefs. Packed disk + large files = nothing can help but a full defragment.

analogika · Jul 20, 2006, 04:02 PM

Except that simply keeping a little more free space will make usage a LOT faster than wasting two hours on a full defragment of a packed disk. AND it will allow OS X to do its highly effective housekeeping-defragment, again making a full defragment virtually pointless.

w00+.

chabig · Jul 20, 2006, 04:08 PM

Don't forget that there are major differences between Windows disks and Mac disks. I think fragmentation is a real problem for Windows, not for us though.

Chris

Rodster · Aug 2, 2006, 01:52 PM

Originally Posted by chabig

Don't forget that there are major differences between Windows disks and Mac disks. I think fragmentation is a real problem for Windows, not for us though.

Chris

That's not the case anymore cause WindowsXP does it's own auto defraging as well. If you have an XP system let it sit for 15-25 minutes. You'll start to see the HDD become active that's because XP initiates an auto defrag and the prefetch files get move moved for faster access.

Also XP monitors file usage and will arrange files on the HDD for quicker performance as well.

I think Symantec had an article about defraging HDD's in both OSX and XP and said you gain very little in either OS especially with the superfast HDD today and the large cache on the newer drives as well.

Curiosity · Aug 6, 2006, 01:51 AM

Originally Posted by Rodster

That's not the case anymore cause WindowsXP does it's own auto defraging as well. If you have an XP system let it sit for 15-25 minutes. You'll start to see the HDD become active that's because XP initiates an auto defrag and the prefetch files get move moved for faster access.

Also XP monitors file usage and will arrange files on the HDD for quicker performance as well.

With Windows, you have to set up defrag in the task scheduler to defrag at regular intervals. The system does not do that on its own. Older versions of Windows used to have a setting whereby frequently used files could be moved closer to the outer part of the drive during defrag, but that is not present in XP.

Tomchu · Aug 6, 2006, 10:14 PM

Wrong. Google for "ProcessIdleTasks".

krx · Aug 7, 2006, 10:06 AM

Every time I do a software upgrade/download, the final step automatically optimizes the disk. I've assumed this once-a-month or so occurence was all the defragging needed.

Chuckit · Aug 7, 2006, 10:17 AM

Originally Posted by krx

Every time I do a software upgrade/download, the final step automatically optimizes the disk. I've assumed this once-a-month or so occurence was all the defragging needed.

That isn't what it means, as far as I know.

CatOne · Aug 7, 2006, 10:31 AM

Originally Posted by krx

Every time I do a software upgrade/download, the final step automatically optimizes the disk. I've assumed this once-a-month or so occurence was all the defragging needed.

No, it's not defragmenting. It could be prebinding, which is something totally different. Though most of the "prebinding" stuff went out when Panther was released.

krx · Aug 7, 2006, 10:41 AM

huh. I am in Panther and I believe it actually says something like "optimizing disk" when finishing a software update. Makes me wonder what it's doing if not, in fact, optimizing ... ??

TETENAL · Aug 7, 2006, 10:51 AM

It says "optimizing system performance" and it's updating prebinding when it says that (afaik).

jbleisure · Aug 8, 2006, 08:12 AM

Is using diskwarrior to repair the disk similar to defragmenting?

Or how does it differ?

I have no indepth technical knowledge but since I boght DW over a year ago I noticed that using it periodically and after upgrades etc did seem to make things run more smootly.

chabig · Aug 8, 2006, 09:32 AM

Originally Posted by jbleisure

Is using diskwarrior to repair the disk similar to defragmenting?

No. They are completely different.

The files on your hard drive are stored in scattered locations across the disk. When you defragment a disk, you are moving the pieces of those files so that they occupy contiguous locations on the drive. This can speed up access because the drive head doesn't have to move around as much to get all of the file's fragments.

The operating system keep track of where those files are located on the drive in a structure called a directory. The directory itself has structure. DiskWarrior rearranges the directory structure so that it can be accesses more quickly. It doesn't move the actual files.

Chris