diff --git a/xCAT-test/autotest/testcase/installation/reg_linux_diskless_installation_flat b/xCAT-test/autotest/testcase/installation/reg_linux_diskless_installation_flat
index ee4b36eaf..b82f23b92 100644
--- a/xCAT-test/autotest/testcase/installation/reg_linux_diskless_installation_flat
+++ b/xCAT-test/autotest/testcase/installation/reg_linux_diskless_installation_flat
@@ -23,7 +23,7 @@ check:output=~$$CN
 cmd:copycds $$ISO
 check:rc==0
 
-cmd:rootimgdir=`lsdef -t osimage __GETNODEATTR($$CN,os)__-__GETNODEATTR($$CN,arch)__-netboot-compute|grep rootimgdir|awk -F'=' '{print $2}'`; if [ -d $rootimgdir ]; then mv $rootimgdir $rootimgdir.regbak;fi
+cmd:rootimgdir=`lsdef -t osimage __GETNODEATTR($$CN,os)__-__GETNODEATTR($$CN,arch)__-netboot-compute|grep rootimgdir|awk -F'=' '{print $2}'`; if [ -d $rootimgdir ]; then mv $rootimgdir $rootimgdir.regbak -f;fi
 check:rc==0
 
 cmd:if cat /etc/*release |grep SUSE >/dev/null;then if [ ! -d /install/custom/netboot/sles ]; then mkdir -p /install/custom/netboot/sles; fi; elif cat /etc/*release |grep "Red Hat" >/dev/null;then if [ ! -d /install/custom/netboot/rh ]; then mkdir -p /install/custom/netboot/rh; fi;fi