diff --git a/xCAT-client/share/xcat/rvid/rvid.xen b/xCAT-client/share/xcat/rvid/rvid.xen
index fac969f6a..8422e2976 100755
--- a/xCAT-client/share/xcat/rvid/rvid.xen
+++ b/xCAT-client/share/xcat/rvid/rvid.xen
@@ -3,4 +3,10 @@
 myport=${rvid_vncdisplay#*:}
 let myport=myport-5900;
 export VNC_VIA_CMD='/usr/bin/ssh -o BatchMode=yes -f -L "$L":"$H":"$R" "$G" sleep 20'
-vncviewer :$myport -via $rvid_server AutoSelect=0 FullColor=1 >& /dev/null
+(
+    flock 200
+    vncviewer :$myport -via $rvid_server AutoSelect=0 FullColor=1 >& /dev/null &
+    sleep 0.2
+    flock -u 200
+) 200> /tmp/xcat/virtvnclock
+