Defrag your disk assets: defragmenting disks on Mac OS X, Snow Leopard
By user12587121 on Sep 21, 2009
Upgrading to Snow Leopard on my MacBook Pro laptop, I was curious about disk defragmentation and wondered whether to do a complete fresh install and so on. Received wisdom to now was by the time one really needs to defragment the disk with Mac OS X, it is time in any case for a new disk.
Mmmm. Clearly some people have thought about this and do not exactly agree: http://www.macattorney.com/ts.html.
Following the mac attorney's article, I did the following:
- used the native Mac OS X Disk Utility to repair permissions
- had the Mac do a disk check and repair itself by booting the Mac into safe mode (by keeping shift pressed after the chime at boot time).
- My disk was at about 70% utilization, so I archived a lot of software packages, videos and VMs I had lying on the hard disk, so got that down to 50% utilization.
- I ran the iDefrag demo software which analyzes the disk (takes about 5 minutes or so). As the article explains, Mac OS X is good at keeping files contiguous but the free space on the disk was at 98% fragmentation.
Mmm...not sure that matters really, but me be thinkin dat aint right nohow, so I bought the full version of iDefrag for 24EUR. 'Hi, I'm a Mac, you will need to pay a third party for system maintenance tools that PC gives you for free.'.
The defragmentation goes like this:
- start this process after work: it took about 3-4 hours to run the full defrag!
- use the CDMaker application included with the commercial copy of iDefrag to create a bootable DVD (a CD is too small) so that iDefrag can do it's work on the offline hard disk. CDMaker downloads a boot template from the internet and burns the DVD. (I tried to get it to load from my Snow Leopard installation disk, but it seemed to take a long time...so I cancelled that and went for the internet option).
- Boot onto the DVD (by holding down the 'C' key after chime at boot time).
- Choose to run a full defrag.
Prior to the defragmentation the free space was pretty much uniformly distributed accross the disk, afterwards it looks alot better: