level 5 is the GUI
and xorg needs to be installed
most servers do not have x installed nor even want it installed
you do NOT need a gui on a headless server ( no monitor so no need for a desktop environment )
if you really MUST add Gnome2 to a server
see the rather old rhel5 install docs
https://access.redhat.com/site/docum...erprise_Linux/
but if there is no monitor physically attached to this server gnome will be of very little use .
for the current older RHEL 5.10 have a look at the output of
for a list of software groups