Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

OracleRedux

macrumors member
Original poster
Nov 21, 2008
56
0
Guildford, UK
I wish to erase free space on my default boot drive "Macintosh HD" using the function provided by Disk Utility.

As I understand it, this process creates a file the same size as the free space on the partition and then proceeds to write to it as many times as specified (1/ 7/ 35). Since this slows down the OS when it is conducted whilst the boot partition is in use I decided to copy the partition to another HDD using Carbon Copy Cloner and then boot from that temporarily.

However, since the back-up HDD is slightly smaller (500GB as opposed to 640GB) I was forced to use the non-block level clone option in order to exclude a couple of large folders.

The other partition boots without any significant errors (just Little Snitch) but when I attempt to run the Disk Utility free space erase program, it throws up an unspecific error.

This is in contrast to what happens when I run the same program from the boot drive and erase free space on the back-up partition, which runs without a hitch.

Any ideas?
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.