I try to install Oracle 11g database on CentOS 5.
There was an error saying
" Checking monitor: must be configured to display at least 256 colors
>>>> Could not execute auto check for display colors using command /usr/bin/xdpyinfo. Check if the DISPLAY variable is set. Failed <<<< "
I try all the xhost configurations and those things work fine. Then I restart my computer.
After I restart the computer I logedin as "Oracle" user. Then I re-try the ./runInstaller.sh. Finally it works.
Initially I login to the system as some one else and use "su - oracle" to change the user on the terminal.
As the solution,
First you should check the login user name. It should "oracle".
If it is oracle user, then try other things like xhost configurations.