diff --git a/perl-xCAT/xCAT/TableUtils.pm b/perl-xCAT/xCAT/TableUtils.pm
index 9f026379c..519f63a98 100644
--- a/perl-xCAT/xCAT/TableUtils.pm
+++ b/perl-xCAT/xCAT/TableUtils.pm
@@ -2013,5 +2013,54 @@ sub updatenodegroups {
     @list = keys %saw;
     $tabhd->setNodeAttribs($node, {groups=>join(",",@list)});
 }
+#-----------------------------------------------------------------------------
+
+
+=head3 rmnodegroups
+    remove groups from the group attribute for the specified node
+
+    Arguments:
+      node
+      tabhd: the handler of 'nodelist' table, 
+      groups: the groups that need to be removed.
+              Can be an array or string. 
+    Globals:
+        none
+    Error:
+    Example:
+         xCAT::TableUtils->rmnodegroups($node, $tab, $groups);
+
+=cut
+
+#-----------------------------------------------------------------------------
+
+sub rmnodegroups {
+    my ($class, $node, $tabhd, $groups) = @_;
+    my ($ent) = $tabhd->getNodeAttribs($node, ['groups']);
+    my @definedgroups;
+    my @removegroups;
+    my @newgroups;
+    if (defined($ent) and $ent->{groups}) {
+        push @definedgroups, split(/,/,$ent->{groups});
+    }   
+    if (ref($groups) eq 'ARRAY') {
+        push @removegroups, @$groups;
+    } else {
+        push @removegroups, split(/,/,$groups);
+    }
+    # take out any groups that match the input list of groups to remove
+    foreach my $dgrp (@definedgroups){
+       if (grep(/^$dgrp$/, @removegroups)) { # is the group to be removed
+          next;
+       } else {  # keep this group
+         push @newgroups,$dgrp;
+       } 
+    }
+    my %saw;
+    @saw{@newgroups} = ();
+    @newgroups = keys %saw;
+    
+    $tabhd->setNodeAttribs($node, {groups=>join(",",@newgroups)});
+}
 
 1;
diff --git a/perl-xCAT/xCAT/Zone.pm b/perl-xCAT/xCAT/Zone.pm
index e790cec36..0b8e7bd67 100644
--- a/perl-xCAT/xCAT/Zone.pm
+++ b/perl-xCAT/xCAT/Zone.pm
@@ -328,14 +328,15 @@ sub usingzones
 
 =head3    getzoneinfo
     Arguments:
+     callback
      An array of nodes
     Returns:
      Hash array  by zonename point to the nodes in that zonename  and sshkeydir
-      zonename1 -> {nodelist} -> array of nodes in the zone
+      <zonename1> -> {nodelist} -> array of nodes in the zone
                  -> {sshkeydir} -> directory containing ssh RSA keys
                  -> {defaultzone} ->  is it the default zone             
     Example:
-     my %zonehash =xCAT::Zone->getNodeZones(@nodearray); 
+     my %zonehash =xCAT::Zone->getzoneinfo($callback,@nodearray); 
     Rules:
        If the nodes nodelist.zonename attribute is a zonename, it is assigned to that zone
        If the nodes nodelist.zonename attribute is undefined:
@@ -421,4 +422,31 @@ sub getzoneinfo
  }
  return $zonehash;
 }
+#--------------------------------------------------------------------------------
+
+=head3    getnodesinzone
+    Arguments:
+     callback
+     zonename 
+    Returns:
+     Array of nodes 
+    Example:
+     my @nodes =xCAT::Zone->getnodesinzone($callback,$zonename); 
+=cut
+
+#--------------------------------------------------------------------------------
+sub getnodesinzone 
+{
+ my ($class, $callback,$zonename) = @_;
+ my @nodes;
+ my $nodelisttab = xCAT::Table->new("nodelist");
+ my @nodelist=$nodelisttab->getAllAttribs('node','zonename');
+ # build the array of nodes in this zone
+ foreach my $nodename (@nodelist) {
+     if  ((defined($nodename->{'zonename'})) && ($nodename->{'zonename'} eq $zonename)) {
+       push @nodes,$nodename->{'node'};
+     }
+ }
+ return @nodes;
+}
 1;