Method to solve Linux xhost: unable to open display

X server provides graphics display services, and receive user input for the graphics applications (like Windows manager) to process. xhost is used to control the access permission of X server.

For example, when you want to use host A to log in host B, for applications, host A is the client; but for graphics, since they’re shown on host A, host A is the server, and X server on it needs to be used. To do this, you need to run xhost + on host A to have other users get permission to visit its X server.

However, when running xhost in Linux environment, there might be some users facing this unexpected issue: unable to open display. How to fix it?

Solution

Step 1: paste the following commands

[root@localhost ~]# vncserver  

New 'localhost:1 (root)' desktop is localhost:1  

Starting applications specified in /root/.vnc/xstartupLog file is /root/.vnc/localhost:1.log  

[root@localhost ~]# export DISPLAY=localhost:1  

[root@localhost ~]# xhost +  

access control disabled, clients can connect from any host

Step 2: Login as root user

Type xdpyinfo command, record all strings behind name of display:

Execute xhost+ to get access control disabled, clients can connect from any host

If cannot get the corresponding result, type export DISPLAY=0 to redo it.

Execute xhost+ ip (the server which you want it to use the service)

Login as oracle user

If the string after name of display: under root login is 127.0.0.1:1.0

Then execute export DISPLAY=:1.0 as oracle user

Step 3: install Xshell 5

Step 4: Select the Linux system you want to connect, enter user name and password.

Step 5: Connection succeeds. startx command information appears.

Besides physical servers, X server can also be used on virtual machines. You can use Vinchin Backup & Recovery to backup VM data for complete data protection. 60-Day full-featured free trial available to download.