KDE: session notes

A "session" in KDE is taken to mean a particular configuration of screens, desktops, windows and programs running within them.

Typically, I set up KDE so that "On login" it "Restores a manually saved session". This setting is available from "Configure desktop" (watch out - this is something entirely different from "Desktop settings" or "Default desktop settings").

In "Configure desktop", click on "Startup and Shutdown" and then on the left side click on "Session Management". There, you will see the setting "Restore manually saved session". This is what you want if you want KDE to start with the same session every time.

Now, to manually save your session, just set up all your screens, desktops, windows, and running programs the way you want them, then go to "Leave" (like you want to turn off the computer), and then click on "Save Session". Voila!

openSUSE, KDE: where are the control panels

openSUSE 12.2 and KDE make a great combination. But finding the "control panels" (or "system settings", or whatever you prefer to call them) can be a bit challenging for beginners. In recent versions of KDE, they go by the name "Configure Desktop". Here's a foolproof way to find that:

1. hit ALT F2 (equivalent of Microsoft Windows XP "Run program")
2. after noticing the "windowlet" (small pop-up window) that opens top and center as a result of performing step 1, type "configure desktop" into it
3. notice that the "Configure Desktop" program is found and its icon is displayed, then press ENTER

xorg.conf, modelines, EDID

Here's a forum contribution I wrote concerning xorg.conf, modelines, EDID, etc.

Latecomer to this thread. I'm wondering if, by any chance, the OP might be using an old VGA cable to connect the external monitor. Modern monitors send Extended Display Identification Data (EDID) to the host computer, but some cables (i.e. older ones), do not pass the signals through on all the pins. When X doesn't get the EDID, it defaults to conservative settings (i.e. 1024x768) and convincing it to run at a higher resolution can be problematic. Not saying that it's a cabling problem in this particular case, but it conceivably could be.

There really should be no need to calculate mode lines and the like. I remember this kind of thing being done back in the 1990s, but today it's more-or-less a relic of the past.

I've found that once I start experimenting with xorg.conf (and /etc/X11/xorg.conf.d), these experiments can come back to haunt me later, especially if I forgot to save the original contents of these critical system files. I mean the contents that were put there by the automated install process or by the desktop environment's configuration mechanisms, which is what I try to use instead of manual editing, if at all possible.

In cases like this, I consider the option of simply moving my data to an external disk and reinstalling. I know the OP said s/he wants to avoid that. Still, what better time to do it with the external monitor not working and 12.3 now out?

Reinstalling is a realistic option for me, because I try my darnedest to make sure all my personal data (including config files, scripts, etc. - everything) resides in my home directory. If I have some home-grown scripts or config files that need to be in /usr or /etc, I put them in /home and symlink from there out to the filesystem. That way, when I need to reinstall, I can just offload my home directory and bring everything back after the reinstall. There's a little bit of work reinstalling applications, etc. and configuring them so everything works the way it did before, but on the other hand I have the benefit of a fresh install, with no skeletons waiting to fall out of the closet in the form of intractable bugs in the setup.

Hope this helps someone.

LXDE notes

• Change keyboard layout: http://wiki.lxde.org/en/Change_keyboard_layouts

KDE: How to hard-restart desktop session?

Having recently switched to openSUSE with KDE (from Debian with Gnome), I'm having to relearn some things. One of these is restarting my desktop session (window manager) when it starts to act flakey.

One option, of course, is to click on the menu (i.e. Kickoff application launcher, or what in Windows parlance would be called the "start menu") and choose "Log out". This will restart the desktop session. But this is tiresome as it requires four mouse clicks, and one must re-aim the mouse each time. And if the window manager is confused, it may not even be possible.

On Debian/Gnome, in such cases I would have to find some way to get to a bash prompt and there type /etc/init.d/gdm restart. On openSUSE 12.2 with KDE, there is no gdm, of course - it uses kdm instead.

# zypper info kdm
Loading repository data...
Reading installed packages...


Information for package kdm:

Repository: openSUSE-12.2-Update
Name: kdm
Version: 4.8.5-2.10.1
Arch: x86_64
Vendor: openSUSE
Installed: Yes
Status: up-to-date
Installed Size: 2.5 MiB
Summary: KDE login and display manager
Description: 
This package contains kdm, the login and session manager for KDE.

And of course:

# ps ax | grep kdm
 1160 ?        Ss     0:00 /usr/bin/kdm

However, in openSUSE there is no /etc/init.d/kdm:

# ls /etc/init.d/*kdm*
ls: cannot access /etc/init.d/*kdm*: No such file or directory

So, how to restart the X session? The answer is to press the key combination CTRL-ALT-Backspace twice in succession. Historically speaking, pressing it once used to terminate the X session, but in openSUSE this has been changed to twice, presumably to make it even less likely that someone might press that combination of keys by accident.

Beware, terminating the X session in this way closes all running programs you started during that session (except those that have been explicitly detached of course).

Remote X via ssh: Can't open display

Remote X has been sacrificed in the name of better security from the get-go. Typically there are several hurdles to overcome in getting it to work. In short, getting remote X sessions to work is a pain. Here's what I came up with on Debian 6.0. All of this has to be done on the machine running the X server.

# Put this one in .xsession or similar startup script
$ xhost +

# It will say "nolisten tcp", but that isn't right
$ ps ax | grep X

# Get rid of "nolisten tcp"
$ sudo vim /etc/gdm/gdm.conf
[security]
DisallowTCP=false

# Throw up an xterm
$ ssh -X pavla /usr/bin/lxterminal

# In the xterm
$ xclock

Voila!