Surprisingly little, actually. Recently I had the experience of working on a server where the hard drive went past 99% full and all the way to 100%. The first thing I knew about it was when I was trying to start a Java process and it gave me this incredibly obtuse error:

# A fatal error has been detected by the Java Runtime Environment:
#
#  SIGBUS (0x7) at pc=0x00007f3e0c5aad9b, pid=17280, tid=139904457242368
#
# JRE version: 6.0_24-b07
# Java VM: Java HotSpot(TM) 64-Bit Server VM (19.1-b02 mixed mode linux-amd64 compressed oops)
# Problematic frame:
# C  [libc.so.6+0x7ed9b]  memset+0xa5b

It turns out that this error shows up when the there is not enough space in the temp area to write anything. (Less than 32 KB left, I think it was.) See more about this problem here.

Apart from that, the server was fine. Everything was chugging away and responding nicely. Somehow I have my doubts that would work on a Windows box.