diff --git a/xCAT/postscripts/syslog b/xCAT/postscripts/syslog
index 34e56bf2f..78d15b5f4 100755
--- a/xCAT/postscripts/syslog
+++ b/xCAT/postscripts/syslog
@@ -38,7 +38,7 @@ config_Rsyslog_C3()
     cp -f $2 $2.XCATORIG
   fi
 
-  grep "xCAT settings" $conf_file
+  grep "xCAT settings" $conf_file 2>&1 1> /dev/null
   if [ $? -gt 0 ]; then
   echo "# xCAT settings" >> $2
     #enable to receive remote logging
@@ -100,7 +100,7 @@ if [ $isLinux -eq 1 ] && [ -a $sysconfig ]; then
 
   #check if it is ryslog version 3, it has totally different settings in /etc/syslog.cong
   if [ $isRsyslog -eq 1 ]; then
-    grep "SYSLOGD_OPTIONS" $sysconfig | grep -e "[\-c 3|\-c3]"
+    grep "SYSLOGD_OPTIONS" $sysconfig | grep -e "[\-c 3|\-c3]" 2>&1 1> /dev/null
     if [ $? -eq 0 ]; then
       isC3=1
     fi
@@ -172,7 +172,7 @@ else
         cp -f $conf_file $conf_file.XCATORIG
       fi
 
-      grep "xCAT settings" $conf_file
+      grep "xCAT settings" $conf_file 2>&1 1> /dev/null
       if [ $? -gt 0 ]; then
         if [ $isLinux -eq 0 ]; then # aix
           echo "# xCAT settings" >> $conf_file
@@ -186,7 +186,7 @@ else
       if [ ! -f $conf_file.XCATORIG ]; then
         cp -f $conf_file $conf_file.XCATORIG
       fi
-      grep "xCAT settings" $conf_file
+      grep "xCAT settings" $conf_file 2>&1 1> /dev/null
       if [ $? -gt 0 ]; then
         echo "# xCAT settings" >> $conf_file
         echo "destination loghost { udp(\"$master\"); };" >> $conf_file
diff --git a/xCAT/postscripts/xcatdsklspost b/xCAT/postscripts/xcatdsklspost
index f09b89a9e..b443d4da9 100755
--- a/xCAT/postscripts/xcatdsklspost
+++ b/xCAT/postscripts/xcatdsklspost
@@ -23,9 +23,9 @@ if [ -e '/etc/SuSE-release' ]; then
    OSVER=`grep -h VERSION /etc/SuSE-release |awk '{print $3}'`
 fi
 
-SIP=`grep -h dhcp-server-identifier /var/lib/dhclient/dhclient*.leases|tail -n 1|awk '{print $3}'|sed -e 's/;//'`
+SIP=`grep -h dhcp-server-identifier /var/lib/dhclient/dhclient*.leases 2> /dev/null|tail -n 1|awk '{print $3}'|sed -e 's/;//'`
 if [ -z "$SIP" ]; then
-    SIP=`grep -h DHCPSID /var/lib/dhcpcd/*.info|awk -F= '{print $2}'|tail -n 1`
+    SIP=`grep -h DHCPSID /var/lib/dhcpcd/*.info 2> /dev/null|awk -F= '{print $2}'|tail -n 1`
 fi
 
 #echo "SIP=$SIP"