====== Problems @ Matfys ======

In this page I am trying to collect all the issues that I solved from time to time, so that I remember how to fix those if needed.

===== Very slow graphical interface on workstation ======

==== Disable Desktop Effects in KDE ====

- Click on the KDE icon and search for ''Desktop Effects''
- Disable effects as in this picture:
{{http://mschlander.files.wordpress.com/2011/01/effects.png?w=720|KDE desktop effects window}}

The above picture belongs to this blog you might want to have a read:
http://mschlander.wordpress.com/2011/01/23/kde-is-slow-for-dummies/

==== NVIDIA video card issues ====

In systems running nvidia graphical cards, sometimes the video driver gets messed up with cached info.
To fix this, run the following as normal user while logged in e.g. KDE:
<code bash>
nvidia-settings -a PixmapCache=0
</code>

Affected systems so far:
<code bash>
root@jarjar 11.4 ~> lspci | grep VGA
01:00.0 VGA compatible controller: nVidia Corporation G98 [GeForce 8400 GS] (rev a1)
</code>

===== System becomes unresponsive and crashes =====

==== Akonadi+nepomuk eating all CPU power and memory ====

You can spot this if you login to a terminal and run ''top''. You'll see processes that contain ''akonadi'' in the name taking over 100% of all cores and memory.

To solve this problem,
- Login on terminal or ssh to any machine with your user.
- cd into your home folder, and run the following:<code bash>
   rm -rf .local/share/akonadi
   rm -rf .config/akonadi
   rm .kde4/share/config/akonadi*
</code>
- logout and try to login graphically. Akonadi should not freak out
anymore.

==== nfs4 mount problems ====

Due to incompatibility trough versions on nfs4, if in the logs such an error appears:
<code io>
Jun 12 13:57:55 balder automount[3145]: umount_autofs_indirect: ask umount returned busy /nfs
</code>

then it seemed more stable to switch to nfs3. This is done in '/etc/nfsmount.conf'. Please ask the administrator for such a fix.

===== Issues printing to the copy machine =====

Most of the issues are due to incorrect code sent to the copy machine.

If you experience problems printing from KDE or command line, follow these instructions:

==== Kde: ====
For some reason KDE incorrectly writes the options for this printer. This is a KDE bug against Canon drivers.

  - Edit the following file: <code>~/.cups/lpoptions</code>
  - If there is a line regarding ''copy-t'' or ''copy-n'', remove that line. Sample correct file is as follows:<file>
Default printer
</file>
  - If you want to specify custom options for the printer, set them in KDE, but then check the content of ''lpotions'' again, it should be something like:<file>
Dest copy-n ColourModel=Colour UserID=None UserPassword=None
Dest copy-t ColourModel=Colour UserID=None UserPassword=None
Default printer
</file>

==== Commandline: ====

It is good to test if printing works by command line.

To pass the codes to the print queue (should not be needed after you do the
KDE thing above, but in any case) issue the following:

''lpr -o UserID=<code> -o UserPassword=<code> -Pcopy-t yourfile''

It seems the driver for this printer is different than the previous one
and KDE always tries to fallback to some weird default.

===== Firefox won't open: another instance is running or similar errors =====

This happens in two cases:

== 1. You have firefox open in workstation A, and you try yo open it in workstation B ==

**Solution**: It's advisable to close it in workstation A first. Each instance of firefox will write in the
same profile folder that might cause problems. To save your work you might want to use the [[https://addons.mozilla.org/en-US/firefox/addon/session-manager/|session-manager extension]]

== 2. Your machine shut down abruptly or lost connection with the fileserver before firefox released the profile lock ==

**Solution**: remove the profile lock using this simple one-liner. 

:!:**OBS**:!:: make sure you **DO NOT** have firefox already running on some other machine or you will cause severe damage to your firefox setup!!

<code bash>find ~/.mozilla/firefox/ -iname '.parentlock' -exec rm {} \;</code>

And try to restart firefox again.