Any Mac defragmenting freeware utility?

The system automatically defrags files under 20MB on the fly.

Not necessary.

If you really want one anyway... Versiontracker lists two.

ooooooh, boy. Here we go again...



http://forums.appleinsider.com/showt...=defragmenting

http://forums.appleinsider.com/showt...g&pagenumber=2

http://docs.info.apple.com/article.html?artnum=25668

curiousburb is right, adding that only highly fragmented files (in 20 or more pieces I think) are deemed necessary to defragment by the OS.

It's called Mac OS X. Free with every copy of Mac OS X.

As Apple's website says, you will /still/ only need a defragmentation tool if your partition is almost full. If it is not, fragmentation will not occur in the first place.

(E.g., if you have 5 Gigs free, you will be able to create several of your 500 Megs-large video files just fine, with negligible fragmentation, even if you edit them afterwards.)

I've checked it- fragmented files do exist and do occur in OSX. Perhaps, it is not as bad as in OS9, but it does exist. It's true for big files and very small files. If you got lots of stuff inbound and outbound (and deleted) on an ongoing basis, it is going to happen. So maybe this built-in OSX defragger works or does not work. ...or maybe it allows some fragmentation, but ultimately never lets it get worse than some nth degree? I dunno. I just wanted to post in and say that even though it is said that OSX handles this automatically, this does not mean that defragmentation does not occur at all. To what degree and if there is ever an impact, I have no idea.

Obviously, if the OS is checking *how* fragmented a file is that's under 20 MB, fragmentation is happening. It's happening above that threshold too, naturally. Point is there that a little bit isn't worth bothering about, and larger files I guess aren't worth sacrificing the resources to defrag in the background.

The point is, fragmentation isn't nearly the issue people like to make it out to be in many cases. My understanding is that larger files might be better off fragmented for faster acess, though I imagine that depends on the degree to which they're fragmented. In this case with these large video files, frankly, if you think affects your work that much, isn't a "real" defragger worth the cost?

Seems to me that we're talking about a trade-off between how OS X and *nixes do this and how every other OS does it. On one hand, OS X defrags many files on the fly when necessary without you having to lift a finger, but in those big cases you would apparently need to buy a defragger. Compare that to my dad's Windows setup where he (overzealously) takes time out of his work to defrag his Dell manually, but it defrags everything on the hard drive, no matter how much it's necessary either.

This topic has been talked to death here and elsewhere. Running defrag software on MacOS X is an exercise in futility. The physical layout and logical layout of MacOS X hard disks are different. The design assumptions of defrag software are not true for these disks.

The "talking to death" is in regard to if there is a performance impact and how much/little. My response was only to affirm that the notion that fragmentation does not exist at all due to some built-in process is erroneous.

Correct - there is *some* fragmentation... but very little in comparison to say, NTFS. (Horrid fragmentation - I've seen 30% in less than a week after a full defrag.) HFS never had the fragmentation problems that other more brain-dead systems did, HFS+ improved on that, and the latest round of improvements (auto-defrag for files under 20MB) make it even better.

*Is* there fragmentation? Of course. I don't know of a file system that has *zero*. (There might be, there are some neat FSs coming out recently.)

Is this fragmentation something that the average Mac user needs to worry about? Nope. (Unlike the average Windows user, who almost certainly *will* see a substantial speedup from a full defrag after just a few weeks of operation.)

Is this fragmentation something that *some* Mac users, such as professional real-time video editors, might want to be concerned with? Yes. In some isolated cases, defragmentation can definitely help. For them, there are good solid commercial utilities to do that task.

Trust me, this isn't something you want to trust to random shareware... a defrag gone bad can screw your drive and data up *HORRIBLY*.

Then the "proper" response to the OP's concerns would have been to advise to seek a professional defragmenter package, not make claims that file fragmentation magically never occurs.

I think you walked away with a total misunderstanding of Kickaha's post. For the vast majority of MacOS X users, including Placebo and you, buying defragmentation software is paying the "Fool's Tax." Shareware defragmentation sofware, if any exists, is a waste of the time required to download it.

I maintain that to separate everybody into 2 distinct groups is to paint with too broad a brush. Some will derive benefits, some will not, and then there will be all the varied cases in between. It is not so clear cut as to cleanly designate who certainly will and who will absolutely not. I would still argue that given useage over long enough time, most everybody would experience a benefit from a defrag. Nor is it accurate to hastily categorize anyone who is remotely concerned with defragmenting measures as some anal-retentative, compulsive nutcase who seeks to defrag every other day or the sky will collapse.

OS X makes this redundant on a system with 'normal' usage (no 60GB files on a 61GB disk etc).
If you really do require defragmentation software then you wouldn't be asking here in the first place.

Dobby.

Kickaha and Amorph couldn't moderate themselves out of a paper bag. Abdicate responsibility and succumb to idiocy. Two years of letting a member make personal attacks against others, then stepping aside when someone won't put up with it. Not only that but go ahead and shut down my posting priviledges but not the one making the attacks. Not even the common decency to abide by their warning (afer three days of absorbing personal attacks with no mods in sight), just shut my posting down and then say it might happen later if a certian line is crossed. Bullshit flag is flying, I won't abide by lying and coddling of liars who go off-site, create accounts differing in a single letter from my handle with the express purpose to decieve and then claim here that I did it. Everyone be warned, kim kap sol is a lying, deceitful poster.

Now I guess they should have banned me rather than just shut off posting priviledges, because kickaha and Amorph definitely aren't going to like being called to task when they thought they had it all ignored *cough* *cough* I mean under control. Just a couple o' tools.

Don't worry, as soon as my work resetting my posts is done I'll disappear forever.

Never again.

Make this a sticky.

One of the best explanations I've read.

Clear, concise, clever. Damn fine post.

Agreed.

Randycat99, you did indeed, for whatever reason, grossly misunderstand and misportray my post and explanation. Simply put, if you are *wondering* if you need a dedicated defragmentation program, it's almost certain you don't. Only those folks who work with data whose characteristics are specific (real-time access is an absolute, large amounts of data that may swamp caching), are going to *need* defragging, or indeed, have any measurable benefits from it... and those folks are already going to be intimately aware of their data transport needs, down to and including purchasing specific drives for their throughput and caching features. In other words, they already know they fall into the 'will definitely benefit from defragging' camp. So they don't need to ask.

Any benefits the average Mac user may perceive from defragging are almost assuredly illusory. Add to that the fact that any defragging run has an inherent amount of risk in it to the integrity of your data, and on the whole, it looks like a waste of time, money, and added unnecessary risk for the average user.

This is not Windows, where defragmentation is a benefit for *almost all users* due to the braindead nature of the file management. The on-the-fly defrag of HFS+ covers the area that will give the most benefit to the most users, with a lower threshold bounded by the hardware characteristics, and an upper threshold bounded by user studies. Those for whom are past the upper threshold as users have commercial options, and are likely to find such an expense to be lost in the noise of their professional financial outlay.

Here is the best article I have ever seen written on the issue:

http://www.kernelthread.com/mac/apme/fragmentation/

Absolutely amazing. If you don't believe it, download his free utility that checks fragmentation for you. I have 0.29% fragmentation... and that's on a 1 year old Panther startup disk.

Also, it's not just the defragmentation on the fly that keeps HFS+ clean. It, unlike NTFS, tries to find a block that's big enough to write the entire file into by delaying immediate writing.

If you really want a free defragmenter, he suggests having his utility check for fragmented files, and then make a copy of them. Chances are, it will have fewer fragments. But, he warns against this as completely unnecessary.

Great article.

Indeed.

Here's my boot volume for my development machine:

Out of 293044 non-zero data forks total, 288828 (98.56 %) have no fragmentation.
Out of 2583 non-zero resource forks total, 2562 (99.19 %) have no fragmentation.


Not bad for a drive that hasn't been formatted since... um... well, I got the machine almost a year ago...

The worst files are all huge - iMovie clips, .cdr images, and a couple of massive .dmg files. I could just copy them elsewhere and that'd take care of it. *shrug*

Where did you get this idea? I was to understand that NTFS does employ that very same technique. When someone describes NTFS as "braindead" relative to HFS+, that gives me doubts as to where that is coming from. They both attempt to do relocated, contiguous writes whenever possible. So what makes one braindead and the other vastly superior? Given this "auto-defragged writes scenario", how does it come about where Windows machines routinely require defragmenting while OSX does not? Something there is just not adding up for me.

Thanks to the link for the fragmentation scanner- interesting and will check out...

WRT the paltry 1-2% fragmentation scores, do bear in mind the brute increases in data size and storage mediums we are dealing with. It's not uncommon to have 10-15 GB of "stuff" comprised of the core OS and closely tied apps (this isn't even including your collection of regular apps and documents). That's a lot of data storage compared to what would fill 1-2 GB of space from the OS9 days. Thankfully, most of that stays put, is read only, and never gets fragged if it wasn't to begin with. There is still the working set of stuff that gets a lot of read and write back activity in the course of a given working day. It just may seem that the working set hasn't really grown much compared to what is stored in that 10-15 GB of "stuff". So it is entirely possible to get really tiny fragmentation scores. However, if the computer is spending most of its time in that working set, and there is fragmentation within that, then the effective impact of fragmentation is possibly "larger" than that reflected in that 1-2% (hope that made sense).

80GB drive, 5GB free, for the above numbers, but your point above is taken. HOWEVER... explain the 25-30% fragmentation seen on Windows machines on a regular basis then?

Am I an expert on the detailed internals of NTFS? No.

I only know the fragmentation I see under NTFS is horrible in comparison to a similarly used HFS+ drive. Period. For *whatever* reason, the *observed* behaviour of NTFS is that of a filesystem that has been badly designed for fragmentation. Claims can be made as to the algorithms used behind the scenes (or attempted to be used), but the bottom line is simply that every Windows machine I've ever used has needed defragmentation on a regular basis, and showed real speedups afterwards for general use. Macs? Not so much. (To be read as: I've never seen double-digit fragmentation on an HFS+ drive, ever. The few times I have defragged, the benefits have been... well, non-existent.)

I would certainly agree with you that fragmentation is endemic in Windows whether it is using FAT32 or NTFS. I am just not so convinced (at this time) that it is because NTFS is inherently inferior in some way. I just wanted to make sure it was noted that NTFS did do the same write contiguous block feature that is cited for HFS+ (that is essentially one of the advantages of choosing NTFS over FAT32, other than security). So either it is something else that HFS+ does to accomplish lesser fragmentation, or perhaps it is just the nature of how Windows runs vs. how OSX runs wrt file access.

While I agree with Kickaha about HFS+, I take it farther. As a Mac user since System 6.0.3 and HFS, I have never seen any noticeable benefit from defragmentation software on a Mac. I have run benchmarks before defragging and afterward on my own computers. I never measured a performance benefit above noise level. When I took my current job, I became the technical support for my secretary's Mac. She had never performed any maintenance at all on the computer in the three years that she had used it. I installed Norton, repaired the hard disk including defragging it. No noticeable performance gain. I had become convinced that defragging was total waste of time ... until I defragged a Windows computer.

I would go further... defragmentation is a dinosaur relic from the '80s. Or maybe the '70s.

I was surprised when Windows NT and NTFS arrived and they still needed defragmentation. Mainstream timeshared/server operating systems had pretty much eliminated fragmentation as a problem back in the '80s. The EARLY '80s. Defragmentation seems like something from the bad old mainframe days, like manual cluster/cylinder management or preallocating maximum file sizes.

HFS+ isn't perfect by any means*, but I would be astounded if fragmentation is a real issue.

* I really wish Apple had followed through on their UFS update in Panther and switched from HFS+ to UFS as the default file system. Yes, they could have done that without losing functionality, by implementing case insensitivity and hooks for things like Spotlight in the vnode layer above the file system, like they do for network shares.

In other words, you get what you pay for. Of course, if you want to load up on free stuff and have no recourse when things get hosed, have at it...