If /root is full, xdm tries to spawn the X server
several times for a minute or so, then dies dumping you
into the login prompt. There is no message that
the /root partition is full. XFS won't start as well.
In this failure mode, for newbies, there SHOULD be a
message or indication of the problem, and it should not
take a minute or so while the X server blinks and tries
to startup. I have duplicated this on both of my Toshiba
Tecra 8000 laptops (neomagic driver).
This is a linux (or even a unix) problem rather than an XFree86
problem. A fix to avoid the problem in the future is to partition your
disk so that root almost never runs out of space -- this usually
means putting /tmp, /var, and /usr on other partitions.
Yeah still ... I've had the problem. And only after 2 reinstalls I
noticed that the root was full. I agree that their should be some
sort of messages about this.