specify text installation mode, otherwise, anaconda will drop into choice dialog when fails to start X in graphic mode

xCAT-server/share/xcat/install/rh/compute.rhel7.tmpl

@@ -85,7 +85,7 @@ install
 #
 # text mode install (default is graphical)
 #
-#text
+text
 
 #
 # firewall
@@ -128,6 +128,7 @@ rootpw --iscrypted #CRYPT:passwd:key=system,username=root:password#
 # OR
 auth --useshadow --enablemd5
 
+
 #
 # SE Linux
 #