Chromium installation

I have successfully installed chromium on my headnode. Then, I began to
install Chromium on my client node. The cluster package I am using is OSCAR.


After I installed OSCAR on my client node, all client nodes rebooted and
entered into a text mode. I coulen't get them boot into graphic mode by
installing xorg-x11 ( as confirmed by the following output),  nvidia driver
for my graphics card, and set the starting mode to 5 from 3 in file
/etc/inittab. It will still go into text mode when reboot.
rpm -aq |grep xorg-x11
xorg-x11-libs-6.8.1-23.EL
xorg-x11-libs-6.8.1-23.EL
xorg-x11-xauth-6.8.1-23.EL
xorg-x11-tools-6.8.1-23.EL
xorg-x11-font-utils-6.8.1-23.EL
xorg-x11-Mesa-libGLU-6.8.1-23.EL
xorg-x11-twm-6.8.1-23.EL
xorg-x11-xfs-6.8.1-23.EL
xorg-x11-6.8.1-23.EL
xorg-x11-xdm-6.8.1-23.EL

Then I try to directly type the following command on my client node text
line:
/chromiumDir/bin/Linux/: atlantis
I got:
freeglut(atlantis): failed to open display ""

What happened?

Thanks,
Michelle