Description of problem: gdm configuration file in /etc/gdm/custom.conf has the following lines # Program to run to draw the background in the standard greeter. Perhaps # something like an xscreensaver hack or some such. # BackgroundProgram= # if this is true then the background program is run always, otherwise it is # only run when the BackgroundType is 0 (None). # RunBackgroundProgramAlways=false The problem is that with 'BackgroundProgram' set to something which is supposed to paint that background and standard greeter try as I might there is nothing changing in a login background. This is in a sharp contrast to the situation in FC4, which is using gdm-2.6.0.5-6, and earlier versions where 'BackgroundProgram' works as expected. One of possible issues that 'BackgroundProgram' runs with gdm.gdm id while owner of a background of a login screen is probably not that. But even making that program setuid root does not change anything. With 'RunBackgroundProgramAlways' set to true when 'BackgroundType' is 0 or 3 ("None" or "Image") I am seeing only a black background does not matter what I am trying. With 'BackgroundType' 1 or 2 one gets a dark blue colour and that is it. The only way I found that it is possible to use 'BackgroundProgram' is to use it with 'BackgroundType' 1 or 3 and that program to make a link, which may change, to some picture file. With this link supplied as 'BackgroundImage' in /etc/gdm/custom.conf one can see, sometimes, effects. Even here an execution rate looks like throttled, so if one has more than one server and would like to provide different backgrounds in an order to be able to distinguish them visually, which is one of "normal" applications of this facility, then this does not work as a link is not switched when the second server is starting because this is "too fast". Big sigh! Version-Release number of selected component (if applicable): gdm-2.14.4-1.fc5.1 How reproducible: always Expected results: When I am running a program to set background it sets it and it runs when it is told to run.
After diving in gdm documentation I found that there are now new configuration options: BackgroundProgramInitialDelay BackgroundProgramRestartDelay with default values beeing in both cases apparently 30 although experiments, when BackgroundProgramRestartDelay was not explicitely set, would suggest that this delay is much longer (over a minute). Setting those configuration options, respectively, to 0 and 1 has effects I was after. At least with gdm-2.15.0-1 from rawhide installed on a test system. Frankly, a default of 30 for BackgroundProgramInitialDelay I am finding somewhat puzzling. The catch is that I am pretty sure that one FC5 machine I run into that for the first time I really could not change that background but maybe I was not waiting long enough and I cannot at this moment retest that there. OTOH on another FC5 (x86_64 this time) changing background this way did work without explicit settings for BackgroundProgramInitialDelay and/or BackgroundProgramRestartDelay so I am a bit baffled. In any case I think that this can be considered closed even if some loose ends appear to exist.