diff --git a/perl-xCAT/xCAT/Usage.pm b/perl-xCAT/xCAT/Usage.pm
index 04cda85e2..9e44a774c 100755
--- a/perl-xCAT/xCAT/Usage.pm
+++ b/perl-xCAT/xCAT/Usage.pm
@@ -326,7 +326,7 @@ my %usage = (
        pdudiscover [<noderange>|--range ipranges] [-r|-x|-z] [-w] [-V|--verbose] [--setup]",
     "switchdiscover" =>
       "Usage: switchdiscover [-h|--help|-v|--version]
-       switchdiscover [<noderange>|--range ipranges] [-s scan_methods] [-r|-x|-z] [-w] [-V|--verbose] [--setup] [--pdu]",
+       switchdiscover [<noderange>|--range ipranges] [-s scan_methods] [-r|-x|-z] [-w] [-V|--verbose] [--setup]",
     "switchprobe" =>
       "Usage: switchprobe [<noderange>] [-V|--verbose | -c|--check]",
     "makentp" =>
diff --git a/xCAT-server/lib/xcat/plugins/pdu.pm b/xCAT-server/lib/xcat/plugins/pdu.pm
index 7242aaf80..e79b906e0 100644
--- a/xCAT-server/lib/xcat/plugins/pdu.pm
+++ b/xCAT-server/lib/xcat/plugins/pdu.pm
@@ -473,7 +473,7 @@ sub process_pdudiscover {
     Getopt::Long::Configure("no_pass_through");
     my %opt;
     if (!GetOptions( \%opt,
-                    qw(h|help V|Verbose x z w r n range=s setup))) {
+                    qw(h|help V|verbose x z w r range=s setup))) {
         my $usage_string = xCAT::Usage->getUsage($request->{command}->[0]);
         $callback->({ data => $usage_string });
         return;
diff --git a/xCAT-server/lib/xcat/plugins/switchdiscover.pm b/xCAT-server/lib/xcat/plugins/switchdiscover.pm
index ec1ebe953..f39141092 100644
--- a/xCAT-server/lib/xcat/plugins/switchdiscover.pm
+++ b/xCAT-server/lib/xcat/plugins/switchdiscover.pm
@@ -24,6 +24,7 @@ use Expect;
 use xCAT::data::switchinfo;
 
 #global variables for this module
+my $device;
 my $community;
 my %globalopt;
 my @filternodes;
@@ -143,7 +144,7 @@ sub parse_args {
     # Process command-line flags
     #############################################
     if (!GetOptions( \%opt,
-            qw(h|help V|Verbose v|version x z w r n range=s s=s setup pdu))) {
+            qw(h|help V|verbose v|version x z w r n range=s s=s setup pdu))) {
         return( usage() );
     }
 
@@ -258,8 +259,10 @@ sub parse_args {
             $globalopt{setup} = 1;
     }
 
+    $device = "switch";
     if ( exists( $opt{pdu} )) {
-            $globalopt{pdu} = 1;
+        $globalopt{pdu} = 1;
+        $device = "pdu";
     }
 
 
@@ -884,7 +887,7 @@ sub snmp_scan {
 
     # snmpwalk command has to be available for snmp_scan
     if (-x "/usr/bin/snmpwalk" ){
-        send_msg($request, 0, "Discovering devices using snmpwalk for @$ranges .....");
+        send_msg($request, 0, "Discovering $device using snmpwalk for @$ranges .....");
     } else {
         send_msg($request, 0, "snmpwalk is not available, please install snmpwalk command first");
         return 1;
@@ -972,7 +975,7 @@ sub snmp_scan {
             $switches->{$mac}->{vendor} = $vendor;
             $switches->{$mac}->{name} = $hostname;
             if (exists($globalopt{verbose}))    {
-               send_msg($request, 0, "found device: $hostname, $ip, $stype, $vendor");
+               send_msg($request, 0, "found $device: $hostname, $ip, $stype, $vendor");
             }
         }
     }
@@ -1196,32 +1199,14 @@ sub xCATdB {
             $mac=" ";
         }
 
-        # check if this is for pdu or switches
-        my $device = "switch";
-        if (exists($globalopt{pdu})) {
-            $device = "pdu";
-        }
-
-
         #################################################
-        # use lsdef command to check if this switch is
-        # already in the switch table
-        # if it is, use chdef to update it's attribute
-        # otherwise, use mkdef to add this switch to
-        # switch table
+        # use chdef command to make new device or update 
+        # it's attribute 
         ##################################################
-        $ret = xCAT::Utils->runxcmd( { command => ['lsdef'], arg => ['-t','node','-o',$host] }, $sub_req, 0, 1);
-        if ($::RUNCMD_RC == 0)
-        {
-            $ret = xCAT::Utils->runxcmd({ command => ['chdef'], arg => ['-t','node','-o',$host,"ip=$ip","mac=$mac","nodetype=$device","mgt=$device","usercomment=$vendor"] }, $sub_req, 0, 1);
-            $ret = xCAT::Utils->runxcmd({ command => ['chdef'], arg => ['-t','node','-o',$host,'-p',"groups=$device"] }, $sub_req, 0, 1);
+        if (exists($globalopt{pdu})) {
+            $ret = xCAT::Utils->runxcmd({ command => ['chdef'], arg => ['-t','node','-o',$host,"groups=$device","ip=$ip","mac=$mac","nodetype=$device","mgt=$device","usercomment=$vendor"] }, $sub_req, 0, 1);
         } else {
-            $ret = xCAT::Utils->runxcmd( { command => ['mkdef'], arg => ['-t','node','-o',$host,"groups=$device","ip=$ip","mac=$mac","nodetype=$device","mgt=$device","usercomment=$vendor"] }, $sub_req, 0, 1);
-        }
-
-        if (!exists($globalopt{pdu})) 
-        {
-            $ret = xCAT::Utils->runxcmd({ command => ['chdef'], arg => ['-t','node','-o',$host,'-p',"switchtype=$stype"] }, $sub_req, 0, 1);
+            $ret = xCAT::Utils->runxcmd({ command => ['chdef'], arg => ['-t','node','-o',$host,"groups=$device","ip=$ip","mac=$mac","nodetype=$device","mgt=$device","usercomment=$vendor","switchtype=$stype"] }, $sub_req, 0, 1);
         }
     }
 }
@@ -1307,12 +1292,6 @@ sub format_stanza {
             $mac = " ";
         }
       
-        # check if this is for pdu or switches
-        my $device = "switch";
-        if (exists($globalopt{pdu})) {
-            $device = "pdu";
-        }
-
         $result .= "$host:\n\tobjtype=node\n";
         $result .= "\tgroups=$device\n";
         $result .= "\tip=$ip\n";
@@ -1354,12 +1333,6 @@ sub format_xml {
             $mac = " ";
         }
 
-        # check if this is for pdu or switches
-        my $device = "switch";
-        if (exists($globalopt{pdu})) {
-            $device = "pdu";
-        }
-
         $result .= "hostname=$host\n";
         $result .= "objtype=node\n";
         $result .= "groups=$device\n";
@@ -1423,7 +1396,7 @@ sub matchPredefineSwitch {
 
         my $node = $macmap->find_mac($mac,0,1);
         if (!$node) {
-            send_msg($request, 0, "Device discovered: $dswitch ");
+            send_msg($request, 0, "$device discovered: $dswitch ");
             $discoverswitch->{$mac}->{ip} = $ip;
             $discoverswitch->{$mac}->{vendor} = $vendor;
             $discoverswitch->{$mac}->{name} = $dswitch;
@@ -1432,13 +1405,14 @@ sub matchPredefineSwitch {
 
         my $stype = get_switchtype($vendor);
 
-        send_msg($request, 0, "Device discovered and matched: $dswitch to $node" );
+        send_msg($request, 0, "$device discovered and matched: $dswitch to $node" );
 
         # only write to xcatdb if -w or --setup option specified
         if ( (exists($globalopt{w})) || (exists($globalopt{setup})) ) {
-            xCAT::Utils->runxcmd({ command => ['chdef'], arg => ['-t','node','-o',$node,"otherinterfaces=$ip",'status=Matched',"mac=$mac","switchtype=$stype","usercomment=$vendor"] }, $sub_req, 0, 1);
-            if (!exists($globalopt{pdu})) {
-                xCAT::Utils->runxcmd({ command => ['chdef'], arg => ['-t','node','-o',$node,"switchtype=$stype"] }, $sub_req, 0, 1);
+            if (exists($globalopt{pdu})) {
+                xCAT::Utils->runxcmd({ command => ['chdef'], arg => ['-t','node','-o',$node,"otherinterfaces=$ip",'status=Matched',"mac=$mac","switchtype=$stype","usercomment=$vendor"] }, $sub_req, 0, 1);
+            } else {
+                xCAT::Utils->runxcmd({ command => ['chdef'], arg => ['-t','node','-o',$node,"otherinterfaces=$ip",'status=Matched',"mac=$mac","switchtype=$stype","usercomment=$vendor","switchtype=$stype"] }, $sub_req, 0, 1);
             }
         }