diff --git a/xCAT-test/autotest/testcase/installation/reg_linux_diskfull_installation_flat b/xCAT-test/autotest/testcase/installation/reg_linux_diskfull_installation_flat
index f330d38f4..2544b86da 100644
--- a/xCAT-test/autotest/testcase/installation/reg_linux_diskfull_installation_flat
+++ b/xCAT-test/autotest/testcase/installation/reg_linux_diskfull_installation_flat
@@ -5,7 +5,7 @@ cmd:if ping -c 1 $$SN > /dev/null;then rpower $$SN off > /dev/null;fi
 
 cmd:chdef -t node -o $$CN servicenode= monserver=$$MN nfsserver=$$MN tftpserver=$$MN  xcatmaster=$$MN
 check:rc==0
-
+cmd:if [[ "__GETNODEATTR($$CN,arch)__" =~ "x86_64" ]];then chdef -t node -o $$CN vmstorage=dir:///var/lib/libvirt/images/ &&  mkvm $$CN -s 15G; fi
 cmd:makedns -n
 check:rc==0
 cmd:makeconservercf