Something's eating my disc space - Mac OS X So something's swallowing about 800gb of disk space on my mac. 

I've ran Disk Inventory X and Omni Sweeper, and both show that my main OS drive only houses 30 GB worth of data. 10GB of that is Home folders from the network share, and the rest I'm guessing is OS based guff.

But where the hell is the other 200 or so?! 

Any ideas?

Thanks.
The biggest issue here is that you need to run your analysis tools as root. If you don't do this, you'll only see the files that your account has access to, and so you won't see everything that is taking up space.

I like GrandPerspective personally. If it's in your Applications folder, the command to run it as root looks like this:

sudo /Applications/GrandPerspective.app/Contents/MacOS/GrandPerspective