Defragmenting isn't talked about much because there isn't much of a need to do it with OSX or Windows Vista and above. Journaled filesystems are much more resistant to fragmenting and defragmentation is done in the background (since Vista in Windows) and since Panther in OSX. You can try iDefrag if you want to. Piece of advice, if your main drive is an SSD, DO NOT DEFRAGMENT.
There are valid reasons why a spinning HD used in music or video production should be defragmented. The important one is that defragging results in one contiguous area of "free space" at "the end" of the drive -- ready to receive new streams of data from the recording process.
DiskWarrior can't do it. All DW does is repair and rebuild drive directories. It will not "relocate" the files that are actually "out there" on the drive's sectors.
You need a defragging application. Some that come to mind:
- iDefrag
- Drive Genius
- TechTool Pro
It's recommended that you BACK UP the drive in question before you run the defragger. I will mention that in practice, I've never had a defrag program muck up a drive in a way that did any damage to it (if the defrag operation was cancelled "in-progress").
Aside:
The "poor man's" way to defrag:
- Copy the contents of the drive (or partition) to another drive (or partition)
- Erase the source drive (or partition)
- Copy the contents BACK from the second drive to the first one.
This works because during a full copy, the files will be copied contiguously, and the "free space" will be left "behind" the copied files -- the results are very similar to those you would see if you ran a defragging app.