[Tfug] disk usage mystery..

[John Gruenenfelder]

I've got an update for you that may help in tracking down the ultimate
culprit of your file system filling bug...

While scouring the Internet with Google to find a solution to the
problem that libvte derived terminals (roxterm, gnome-terminal, etc.)
are treating End and CTRL-End as the same key (End), I found a bug
report stating that gnome-terminal (again, via libvte) was constantly
writing to /tmp.  Remembering your plight, I took a look.

Some of the suggestions in the following bug report threads may help:

https://bugs.launchpad.net/ubuntu/+source/vte/+bug/865082
https://bugzilla.gnome.org/show_bug.cgi?id=631685

In short, one of the temp files libvte stores in /tmp contains the
entire scroll-back buffer and it is writing to it constantly.  Like
most transient temp files, it is opened for read/write access and then
deleted from the file system (but remains open as long as the creating
process is alive).  Given how much sensitive information can
potentially be displayed in a terminal, I certainly hope they've got
the security concerns nailed down.  As somebody who does not use a
stupendously large buffer size, I naturally assumed that it was stored
in RAM.  For that matter, even for a giant buffer I still would have
assumed that it was kept in memory.

Anyway, the second link above suggests a very useful way for
monitoring file system access.  You can use the kernel's inotify
system and a simple Python command to have all of this information
streamed to a terminal or file:

  python -mpyinotify /tmp

You will need Python's inotify bindings (in Debian, this is the
python-pyinotify package).  It's fairly easy to read and even
colorized.  Obviously, don't run this in a terminal that will be
hammering /tmp.  Regular xterm will work fine.  Similarly, if you dump
the output to a file, make sure you are not storing that file in the
same place you are monitoring.  By default, this seems to recursively
monitor the path you specify.  I created some directories a couple of
levels deep and touched a file inside and Python was still notifying
me of the access.

I hope this makes solving your problem a little easier.


P.S. I still haven't found a solution to my End=CTRL-End problem with
libvte.  It works fine with xterm, though.  I map CTRL-Home/End to
jump to the beginning/end of a buffer in EMACS so it's not a show
stopper, just annoying.  The devs are at least aware of it, via an
Ubuntu bug report, but the last activity was a year and a half ago...
:(


-- 
--John Gruenenfelder    Systems Manager, MKS Imaging Technology, LLC.
Try Weasel Reader for Palm OS  --  http://weaselreader.org
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