Just some notes about the display manager(s) on Ubuntu I found out over time, and about their startup settings.
The display manager – that’s usually gdm, the gnome d.m.; alternatively kdm on kubuntu/kde, or even the good old xdm when using a lightweight desktop. In any case, it’s usually started to show a user login screen ;)
Text modeIt is often practical to boot into text only mode – at least, when you know a bit about linux. I’m not talking about removing gdm forever (apt-get remove gdm or update-rc.d -f gdm remove do this), but to use text mode in certain situations – including when you know your Xorg or gdm setup to be broken. Or, when you really want to save battery power ;)
The gdm startup allows this by putting text into the kernel command line. If this parameter is found, /etc/init.d/gdm just exits again. This can be achieved by:
- stop the bootup in the grub menu, then
- press “e” to edit the wanted entry
- use the cursor keys to select the “kernel” line
- press “e” again to edit the line
- go to the end of the line and add “text”
- press return to leave the line editing
- press “b” to boot the edited entry
- create a grub entry for text mode
- sudo gedit /boot/grub/menu.lst
- copy the first real boot entry (that starts with “title”) into another one below
- change the title – append “text mode” or such
- add “text” to the end of the “kernel” line
- next time you boot the system, you can select the text mode and have tun.
By the way: I have not hardly anything about this on the web. Of course, you just need to look into /etc/init.d/gdm … the only post I found referring to this is https://bugs.launchpad.net/ubuntu/+source/gdm/+bug/294980
gdm, kdm and xdmEver wondered how the various display managers that can be installed on (k)ubuntu stay out of each others hair?
- each of them may be added to the runlevels
- when starting, they each check whether they are the “preferred display manager” via /etc/defaults
- if no, they exit; if yes, the one that should starts.
sysv-rc-confAs a side note – I never know how to edit the /etc/rc.d?/scripts. This changed over time, mainly because of the linux standard base (LSB), I believe. The current command-line tool is update-rc.d which is not really nice to use.
But, the package sysv-rc-conf contains a textmode ui tool of the same name which seems to be usable, at least.
There is also chkconfig and insserv as I know from opensuse; yet, their packages refuse to install on Jaunty due to some sysv-init package conflicts. Probably because ubuntu migrated from sysvutils to sysvinit-utils. Or rather to upstart, where sysvinit-utils only contains some utilities.