VNC to RH6.10 getting blank screen

When I use vncviewer to a Redhat 6.10 server I got blank screen.

The original xstartup file has the following content


The log has the following errors:
xterm: command not found
gnome-session: command not found

Then I installed above packages:
yum install xterm
yum install gnome-session

After I restarted vncserver, I can see desktop but no menu, no terminal window.

Then I replaced xstartup content with the following


After restart vncserver, now I have desktop + a terminal window running in it. It's all I need as I need to install Oracle from there