diff --git a/instances/templates/instance.html b/instances/templates/instance.html
index f50de4f..c1549d2 100644
--- a/instances/templates/instance.html
+++ b/instances/templates/instance.html
@@ -1197,15 +1197,10 @@
     }
 </script>
 <script>
-    function random_mac(net) {
-        var hexDigits = "0123456789abcdef";
-        var macAddress="52:54:00:";
-        for (var i=0; i<3; i++) {
-            macAddress+=hexDigits.charAt(Math.round(Math.random()*16));
-            macAddress+=hexDigits.charAt(Math.round(Math.random()*16));
-            if (i != 2) macAddress+=":";
-        }
-        $('input[name="clone-net-mac-'+net+'"]').val(macAddress);
+   function random_mac(net) {
+        $.getJSON('/instance/random_mac_address/', function(data) {
+            $('input[name="clone-net-mac-'+net+'"]').val(data['mac']);
+        });
     };
 </script>
 <script>
@@ -1305,7 +1300,11 @@
             $("#console_select_listen_address option[value='" + console_listen_address + "']").prop('selected', true);
         }
     });
-{% if not request.user.is_superuser %}
+{% if request.user.is_superuser %}
+    $(document).ready(function () {
+        random_mac(0);
+    });
+{% else %}
     $('#select_clone_name').on('change', function () {
         update_clone_disk_name($(this).val());
         guess_mac_address('#select_clone_name', 0);
@@ -1328,7 +1327,6 @@
 <script>
     function network_select_enable(){
         // set network button enabled
-
         var selected = $('network_select').val();
         if (selected != "to Change") {
             $('button[name="change_network"]').removeAttr('disabled');
diff --git a/instances/urls.py b/instances/urls.py
index dfba916..93ac0c4 100644
--- a/instances/urls.py
+++ b/instances/urls.py
@@ -2,18 +2,12 @@ from django.conf.urls import url
 from . import views
 
 urlpatterns = [
-    url(r'^(?P<compute_id>[0-9]+)/(?P<vname>[\w\-\.]+)/$',
-        views.instance, name='instance'),
-    url(r'^statistics/(?P<compute_id>[0-9]+)/(?P<vname>[\w\-\.]+)/$',
-        views.inst_graph, name='inst_graph'),
-    url(r'^status/(?P<compute_id>[0-9]+)/(?P<vname>[\w\-\.]+)/$',
-        views.inst_status, name='inst_status'),
-    url(r'^guess_mac_address/(?P<vname>[\w\-\.]+)/$',
-        views.guess_mac_address, name='guess_mac_address'),
-    url(r'^guess_clone_name/$',
-        views.guess_clone_name, name='guess_clone_name'),
-    url(r'^check_instance/(?P<vname>[\w\-\.]+)/$',
-        views.check_instance, name='check_instance'),
-    url(r'^sshkeys/(?P<vname>[\w\-\.]+)/$',
-        views.sshkeys, name='sshkeys'),
+    url(r'^(?P<compute_id>[0-9]+)/(?P<vname>[\w\-\.]+)/$',  views.instance, name='instance'),
+    url(r'^statistics/(?P<compute_id>[0-9]+)/(?P<vname>[\w\-\.]+)/$', views.inst_graph, name='inst_graph'),
+    url(r'^status/(?P<compute_id>[0-9]+)/(?P<vname>[\w\-\.]+)/$', views.inst_status, name='inst_status'),
+    url(r'^guess_mac_address/(?P<vname>[\w\-\.]+)/$', views.guess_mac_address, name='guess_mac_address'),
+    url(r'^guess_clone_name/$', views.guess_clone_name, name='guess_clone_name'),
+    url(r'^random_mac_address/$', views.random_mac_address, name='random_mac_address'),
+    url(r'^check_instance/(?P<vname>[\w\-\.]+)/$', views.check_instance, name='check_instance'),
+    url(r'^sshkeys/(?P<vname>[\w\-\.]+)/$', views.sshkeys, name='sshkeys'),
 ]
diff --git a/instances/views.py b/instances/views.py
index 85f31cb..5189ace 100644
--- a/instances/views.py
+++ b/instances/views.py
@@ -5,7 +5,7 @@ import socket
 import crypt
 import re
 import string
-from random import choice
+import random
 from bisect import insort
 from django.http import HttpResponse, HttpResponseRedirect
 from django.core.urlresolvers import reverse
@@ -526,7 +526,7 @@ def instance(request, compute_id, vname):
                 cache = request.POST.get('cache', '')
                 target = get_new_disk_dev(disks, bus)
                 
-                path = connCreate.create_volume(storage, name, size, format, meta_prealloc, extension)
+                path = connCreate.create_volume(storage, name, size, format, meta_prealloc)
                 conn.attach_disk(path, target, subdriver=format, cache=cache, targetbus=bus)
                 msg = _('Attach new disk')
                 addlogmsg(request.user.username, instance.name, msg)
@@ -909,10 +909,10 @@ def inst_graph(request, compute_id, vname):
     response.write(data)
     return response
 
-@login_required
-def guess_mac_address(request, vname):
+
+def _get_dhcp_mac_address(vname):
     dhcp_file = '/srv/webvirtcloud/dhcpd.conf'
-    data = {'vname': vname, 'mac': '52:54:00:'}
+    mac = ''
     if os.path.isfile(dhcp_file):
         with open(dhcp_file, 'r') as f:
             name_found = False
@@ -920,10 +920,37 @@ def guess_mac_address(request, vname):
                 if "host %s." % vname in line:
                     name_found = True
                 if name_found and "hardware ethernet" in line:
-                    data['mac'] = line.split(' ')[-1].strip().strip(';')
+                    mac = line.split(' ')[-1].strip().strip(';')
                     break
+    return mac
+
+
+@login_required
+def guess_mac_address(request, vname):
+    data = { 'vname': vname }
+    mac = _get_dhcp_mac_address(vname)
+    if not mac:
+        mac = _get_random_mac_address()
+    data['mac'] = mac
     return HttpResponse(json.dumps(data))
 
+
+def _get_random_mac_address():
+    mac = '52:54:00:%02x:%02x:%02x' % (
+        random.randint(0x00, 0xff),
+        random.randint(0x00, 0xff),
+        random.randint(0x00, 0xff)
+    )
+    return mac
+
+
+@login_required
+def random_mac_address(request):
+    data = {}
+    data['mac'] = _get_random_mac_address()
+    return HttpResponse(json.dumps(data))
+
+
 @login_required
 def guess_clone_name(request):
     dhcp_file = '/srv/webvirtcloud/dhcpd.conf'
@@ -940,6 +967,7 @@ def guess_clone_name(request):
                         return HttpResponse(json.dumps({'name': hostname}))
     return HttpResponse(json.dumps({}))
 
+
 @login_required
 def check_instance(request, vname):
     check_instance = Instance.objects.filter(name=vname)