Subject: Bug#1332:

From: Michael Büchler <[email-masked]>
Date: Wed, 15 Apr 2020 17:49:35 +0200

Package: X2Go Server
Version: 4.1.0.3-0~1708~ubuntu18.04.1 am64

I had the same issue: this morning I suddenly couldn't connect after a
few weeks of usage.

Turned out my root filesystem was 100% full.

Who did this? X2Go, apparently. This file was 254 GiB in size:
/tmp/.x2go-username/C-username-50-blabla/cmdoutput

First I removed that file, then I found out that there were still
processes with active file descriptors on that (deleted) file. Thus the
filesystem didn't release the space.

These processes can be found by using 
# lsof | grep cmdoutput

To let the filesystem free the space I tried this and it worked:
# ls -l /proc/15644/fd/
# cat /dev/null > /proc/15644/fd/1
where 15644 is the PID of one of these processes and 1 is the fd number
that points to the deleted file.

And when I say "I tried this" then I mean "I googled for some
stackexchange results and applied them", of course.

Maybe this helps someone in a similar situation. Or is it even a bug in
X2Go? Long solved in recent versions that you get on a decent distro?

Regards
Michael