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 f52bda468..9769750c6 100644
--- a/xCAT-test/autotest/testcase/installation/reg_linux_diskfull_installation_flat
+++ b/xCAT-test/autotest/testcase/installation/reg_linux_diskfull_installation_flat
@@ -19,6 +19,7 @@ cmd:makedhcp -n
 check:rc==0
 cmd:makedhcp -a
 check:rc==0
+cmd:sleep 10
 cmd:if cat /etc/*release |grep SUSE >/dev/null;then cat /var/lib/dhcp/db/dhcpd.leases|grep $$CN;elif cat /etc/*release |grep "Red Hat" >/dev/null;then cat /var/lib/dhcpd/dhcpd.leases|grep $$CN;fi     
 check:output=~$$CN