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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: KDE desktop effects window

The above picture belongs to this blog you might want to have a read:

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:

nvidia-settings -a PixmapCache=0

Affected systems so far:

root@jarjar 11.4 ~> lspci | grep VGA
01:00.0 VGA compatible controller: nVidia Corporation G98 [GeForce 8400 GS] (rev a1)

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:

   rm -rf .local/share/akonadi
   rm -rf .config/akonadi
   rm .kde4/share/config/akonadi*

- 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:

Jun 12 13:57:55 balder automount[3145]: umount_autofs_indirect: ask umount returned busy /nfs

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:


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

  1. Edit the following file:
  2. If there is a line regarding copy-t or copy-n, remove that line. Sample correct file is as follows:
    Default printer
  3. 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:
    Dest copy-n ColourModel=Colour UserID=None UserPassword=None
    Dest copy-t ColourModel=Colour UserID=None UserPassword=None
    Default printer


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 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!!

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

And try to restart firefox again.

it_services/mf/problems.txt · Last modified: 2020/08/20 17:01 by florido

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