What is filling up my hard drive so fast? Last night (Because my hard drive was almost full) I freed about 4GB. Then I came back to my Macbook about 3hrs later (I left it idle) and Its was full again.

Is something is eating my mac?

If I go to /About This Mac/Info/Storage then it says I have 90GB of "Other"

This worries me and I thought it was just me imagining things, but I think there IS something wrong with my mac as I believe that it was also happening when i had Mountain-Lion before Mavericks.

Edit: Activity Monitor

launchD 1.28GB Written

Kernel_task 764MB Written

mds 475MB Read


Now this a list of the user column (note I am the only user on this Mac):


root
_mdnsresponder
_spotlight
_softwareupdate
_locationd
_networkd myname
Here's the systematic way to find where the disk space went: Open a window in Terminal (you find this under Utilities), then type:

cd /
sudo du -sm *


This will give you the disk consumption, in megabytes, of every top level entry in the folder hierarchy. 

You could then drill down further, but without a good idea of what things do, you might easily decide on a wrong culprit (in particular, don't go around deleting random files in /System; that is bound to end in tears).

However, since your system keeps filling up by itself, you can just let it sit for an hour, and then run the du command above again. The difference between the two sets of numbers will show you where the space went.

In particular, if logging is a problem, you might see the number for /private go up.