To change this attribute, you must have root privileges.
This file can be in a variety of locations. On IRIX, the file is in /var/X11/xdm/Xservers. Most Linux distributions place the file in /etc/X11/xdm/Xservers. You may have to look around for your Xserver configuration files.
An example of the /var/X11/xdm/Xservers file on IRIX:
:0 secure /usr/bin/X11/X -bs -nobitscale -c -pseudomap 4sight -solidroot sgilightblue -cursorFG red -cursorBG white
- Most people's Xservers contain one entry with several whitespace-separated fields. This entry starts with the name/number of the Xserver display. Usually this entry is for the default, :0 display. This line will also contain a keyword (on IRIX its usually secure), and then the server command line. This command line is where the backing store option is specified.
- There will usually be several options in the server command line, and the one you're interested in is "-bs", which turns off backing store. You want to edit this line to remove the "-bs" option from this file, (thereby allowing bs), and save.
This varies by system, but usually logging out and back in again will cause the Xservers file to be read in again by the program that starts the Xserver. On IRIX, you can usually force the situation by pressing "Control + Alt + Shift + F12 + Keypad-/", and on Linux you can do the same by pressing "Control + Alt + Backspace".