[freudling]

Norton? Disk Warrier?...

[budster101]

Disk Warrior. Norton SUCKS Richard.

[ATPTourFan]

Originally Posted by freudling

Norton? Disk Warrier?...

Not really necessary on Mac OS X with a HFS+ volume. All files are automatically defragged (or written contiguously if possible) as long as they're not large files.

The system will also build an optimized grouping of files called the hotfiles.btree to speed up boot times.

Of course, if you don't have much free space available, you may have a lot of fragmented files. Faster drives with relatively huge caches can make this a non-issue. However, I would use a utility like DiskWarrior to optimize your disk's directory, instead of the actual placement of files on the disk.

Basically, the benefit from having a cleanly defragged and optimized disk has been reduced as disks' performance has increased and the operating system/file system both actively attempt to reduce fragments.

Here are the actual rules HFS+ uses in actively defragging the drive (from an awesome article on the subject: http://www.kernelthread.com/mac/apme/fragmentation/ )

On-the-fly Defragmentation
When a file is opened on an HFS+ volume, the following conditions are tested

If the file is less than 20 MB in size
If the file is not already busy
If the file is not read-only
If the file has more than eight extents
If the system has been up for at least three minutes
If all of the above conditions are satisfied, the file is relocated -- it is defragmented on-the-fly.

[ATPTourFan]

Originally Posted by budster101

Disk Warrior. Norton SUCKS Richard.

DiskWarrior alone only optimizes and repairs your file directory (which is very important). It does not defragment/optimize the data and its placement on the selected volume. Alsoft has another program that defrags/optimizes called PlusOptimizer (not yet compatible with Tiger). This program is a compliment to the crucial services of DiskWarrior.

[budster101]

Disk Warrior is still better than anything Norton. Norton Blows... so if you need any program to fix your hard drive, Disk Warrior is recommended.

Re: ATP, his advice was spot on. I learned quite a bit from his information! as you will.

Thanks.

[CharlesS]

Norton sucked even before Tiger, but on Tiger it is not compatible with your system. Tiger changes the way that the OS uses the HFS+ file system, and any disk utility that has not been updated for Tiger will damage the file system. And Norton has not been updated for Tiger, since development on it has stopped.

Bottom line: Don't use Norton on an OS X disk.

[mania]

I remember when it was called Snortin Futilities...

[Thinine]

iDefrag is supposed to be pretty good.

And while it's possible that the hotfiles.btree file speeds boot, it really just keeps track of often accessed files and moves them to the faster part of the disk.

[headbirth]

I don't think DiskWarrior is a hard drive defrager ... it only defrags directory catalogs.

Since it's so rare that anyone might need to defrag their drive in X, why not do an archive, erase and reinstall with a tool like CarbonCopy Cloner. Probably a lot quicker as well.

[Millennium]

Originally Posted by headbirth

I don't think DiskWarrior is a hard drive defrager ... it only defrags directory catalogs.

Exactly. Alsoft made a program for true defragging a long time ago, but it was never updated for OSX, and so it can only be used on a machine which can boot OS9 natively (Classic won't work).

Do recent Apple desktops support Target Disk Mode the way laptops do? If so, then you'd only need one OS9-bootable machine, because you could use TDM to feed the other machines to it. This would cause problems with journaling, though; OS9 never supported that.

[Maflynn]

With today's disk drives and most people's habits and needs the need to defragment is simply not there.
Here's Apple's KB on it.

I've never defragged my HD in OSX or prior and to be honest, I've never noticed a speed degredation.

By the same token, on PCs things have come to a crawl that the only recourse is defrag and after that it was a marked improvement.

Mike

[tooki]

Originally Posted by Millennium

Do recent Apple desktops support Target Disk Mode the way laptops do? If so, then you'd only need one OS9-bootable machine, because you could use TDM to feed the other machines to it. This would cause problems with journaling, though; OS9 never supported that.

Every Mac with AGP graphics supports FW Target Disk Mode.

You are correct, though: I would NOT recommend running PlusOptimizer on a Tiger machine via TDM on an OS 9 Mac -- TDM does not convert the filesystem, so you would still damage the disk. PlusOptimizer is NOT aware of journaling, etc, and could cause data loss on a disk formatted with 10.3 or higher.

tooki

[wataru]

This question gets asked just about every week. I don't know why people don't tell posters to just do a search.

Here's my obligatory spiel: OS X does some defragging for you, not all. Last time I checked with Drive 10, I had tens of thousands of both file and free space fragments. I don't do anything super intensive with my computer, so I imagine that's pretty typical.

Here's the problem: OS X doesn't automatically defragment free space. If your hard drive doesn't have a lot of free space left, then what is available is likely fragmented into many small chunks. When the system needs to write a swap file, which can get very large, it might have to break the swap file up into chunks, causing significant slowdown.

Everyone tells you to leave HFS(+) drives at least 15% empty. Unfortunately, that's not always easy, especially on laptops with more limited drive sizes and stricter mobility requirements. If you can't keep enough hard drive space open to ensure contiguous spots for swap files (this is likely a couple gigabytes, depending on how much you swap out, which in turn depends on how much RAM you have and what kinds of apps you run), you may benefit from defragging.

Unfortunately, Drive 10 is maddeningly slow at defragging. What I do instead is to clone my internal drive to an external one with Carbon Copy Cloner, and then wipe the internal one and clone back.

Edit: The iDefrag website claims:

the swapfile must be contiguous on the disk, so you can actually run out of virtual memory long before you run out of disk space if your free space is fragmented.

That's news to me. Can anyone confirm that swap files must be contiguous, and that you can "run out of virtual memory?"

Also, I'd like to thank the OP for flaming me in a PM for saying he should have done a search first. I'm glad I could help.

[siflippant]

There's always this one...

http://www.coriolis-systems.com/iDefrag.php