Detached sessions not being created

[Mark Adams]

I have several machines on my network that provide services of one type or another. I'm trying to configure them to create detached screen sessions at boot time. Let's take a representative example.

I have a cron job setup under my user ID:

@reboot /usr/bin/screen -d -m -S pvr

I have also used the syntax "@reboot /usr/bin/screen -dmS pvr".

Neither of these has worked.

I tried creating a bash script:

#!/bin/bash
# This script starts a detached screen session on boot.
su - <my_user> -c "/usr/bin/screen -dmS pvr"


Neither of these work despite the fact that when I run the command 
"/usr/bin/screen -d -m -S pvr" as my user in a konsole window it creates
 the screen session as expected (note that I can stack those options to 
-dmS and it makes no difference).

I should say that I'm also 
unable to start that screen session from crontab in Webmin (I assume it 
uses the run-parts command to do that). I get no error - it just doesn't
 create the screen session.

I set uid root: "chmod a+s /usr/bin/screen" and I have seen references to changed the permissions of /var/run/screen.  I have no /var/run/screen.


Any wisdom?

Thanks.

-- 
Mark Adams