Xlib: connect to ":0.0" refused by server not able to lauch Oracle GUI

When I am trying to install oracle from Oracle Enterprise Linux I got the below error while launching GUI Interface.

Xlib: connect to ":0.0" refused by server

Xlib: No protocol specified

xhost: unable to open display ":0.0"

I am able to execute xhost commands from root user, whereas when i am running it with oracle user i am getting the above error.

To resolve it

root > xhost +

output --- access control disabled, clients can connect from any host

login from oracle using other terminal, run the below command to verify whether xhost commands are working or not

oracle > xclock --> If it displays clock then you directly launch oracle Installation GUI using runInstaller

If not login into Lunix using oracle login then type startx, you will be able to work with xhost.



error while loading shared libraries: /opt/cubrid/lib/libclntsh.so.llxxxx: cannot restore segment prot after reloc: Permission denied

Yesterday I installed Oralce in my VMWare workstation, after installation I encountered the below error while running sqlplus command to connect to SQL

error while loading shared libraries: /opt/cubrid/lib/libclntsh.so.llxxxx: cannot restore segment prot after reloc: Permission denied


I am able to fix the below issue by using the below command.

Why do we get the error?

If the linux distribution has SEX Linux enabled, (Security-enhanced Linux) then we may get the error.

To disable the feature temporarily

/usr/sbin/setenforce 0  (Execute from root user) -- Zero to disable, One to enable
/usr/sbin/setenforce 1 -- Enables the feature

After disable the feature temporarily i am able to login into sqlplus.

To disable the feature permanently.

vi /etc/selinux/config

Include comment infront of SELINUX=enforcing line and include the below line
SELINUX=disabled

Reboot the server to get this feature on.