Hi, again -
1. "X Windows" is your GUI - I'm guessing that you probably don't want to disable it.
If you do, the easiest way is to change your default run level. For now, let's not discuss "What's a runlevel?" or "How do I change it?"
2. Back to the problem at hand:
It looks like you're using your X Windows GUI, and that one of your GUI programs went berserk and max'ed out your filesystem with an 18GB log.
There are many ways for this to happen.
3. What you need to do is:
a) be aware of what programs you're using
b) Keep an eye on the .xsession-errors log to make sure it stays a reasonable size
4. If the problem *does* recur, then:
c) See if the .xsession-errors log identifies the culprit
d) Otherwise, run "top". The odds are good that the culprit will be doing the most I/O and/or using the most CPU time.
e) Fix, disable or update the culprit (for example, get a new copy of "mplayer").
X Windows is not the culprit; the enormous log was just a side-effect of the root problem.
'Hope that helps .. PSM
No, you don't need to reboot the PC for an X Windows error. But you should *always* cold-boot the PC and run "fsck" if you ever have a disk-related crash (as you did when your filesystem became full).