equivalent to disk defrag?

You don't really need to disk optimize running OS X, that's the word from Apple.

http://support.apple.com/kb/ht1375

If you are sensible and keep a backup then even if your HD became very "fragmented" all you would need to do is erase the disk and then restore from the backup...POW..."fragmentation" gone!

Welcome to the Apple Discussions!

You do not really need to defrag Macs. Mac OS X self defrags unless you have a lot of really huge files. One of the easiest ways to defrag is to clone the HDD and then copy the clone back. Any really large files that were fragmented will have been defragged during the cloning.

As far utilities, there are a few. I like OnyX.

Dah•veed

I'm not as fond of Onyx as some utilities, because misused it can damage one's cache files. Number one utility you should have is a backup utility*:

http://www.macmaps.com/backup.html

The closest equivalent to defrag on your Mac you might do, and only on a backed up system, is repair the directory*:

http://www.macmaps.com/directoryfaq.html

- * Links to my pages may give me compensation.

David.Austin.Allen wrote:

You do not really need to defrag Macs. Mac OS X self defrags unless you have a lot of really huge files. One of the easiest ways to defrag is to clone the HDD and then copy the clone back. Any really large files that were fragmented will have been defragged during the cloning.

As far utilities, there are a few. I like OnyX.

Hi.

I have a 1.5TB Firewire disk which has a lot of really huge files, most of them video files and EyeTV recordings between 1GB and 8GB in size. When there's less than 20GB free on the volume, it gets r.e.a.l.l.y s.l.o.w, to the extent that it can't keep up with live TV, and iMovie works like treacle. There's a lot of system activity when it's recording, which I'm sure is Mac OS X fiddling all the time with its "hot blocks".

OK, I know (before everyone points out) that the disk is really too full. But I don't need "hot blocks". It's not a system disk, there are no apps, no libraries on the disk. I don't have another 1.5TB disk to clone to. It sure feels like it needs defragging.

Any suggestions much appreciated 🙂

An absolute must app is AppleJack:

http://applejack.sourceforge.net/

It's free and runs native OSX maintenance scripts.

This is an important app to install! You can use it on regular bases to run disk maintenance and the normal UNIX maintenance scripts as well as clean out cache.

What's nice about this program is that you run it from Single User mode. That's a very nice feature as someday you may not be able to load OSX from the internal disk. But you'll likely be able to boot into Single User mode and run maintenance items from there. Which might help you get up and running.

But as stated before... Due to the UNIX OS design, defrag is not necessary unless you're doing serious video work. That's why you do not see a lot of defrag programs out there for OSX or other UNIX OS's.

Message was edited by: iyacyas

Contrary to what the Apple article says I found that I after a short time maybe not even a month my mini harddrive was so fragmented that I was not even able to partition the drive to install BootCamp!
I even tried deleting and moving all the large files off the drive to see if that helped but nothing worked. None of the free defragment tools for Macosx I tried did anyways so in the end I had to totally reformat the drive to be able to partition it for Bootcamp 😟

Techtool pro 5 has very good volume optimization tools, plus directory rebuilding built in. Well worth the money and has make a very noticeable difference in the performance of my mini.

Agreed, it is a good tool, still not to be used without a backup.

see _*Maintaining Mac OS X*_.

J GG

.

also, there is _*Mac OS X Routine Maintenance*_.

J GG