diff --git a/plstackapi/core/admin.py b/plstackapi/core/admin.py
index a562911..039ac17 100644
--- a/plstackapi/core/admin.py
+++ b/plstackapi/core/admin.py
@@ -233,17 +233,17 @@
     list_display = ('slice','cidr', 'start', 'end', 'ip_version')
 
     def save_model(self, request, obj, form, change):
-        # update openstack connection to use this subnet's slice/tenant
-        client = OpenStackClient(tenant=obj.slice.name, **request.session.get('auth', {}))
-        obj.driver = OpenStackDriver(client=client)
-        obj.caller = request.user
+        # update openstack connection to use this site/tenant
+        auth = request.session.get('auth', {})
+        auth['tenant'] = obj.slice.name
+        obj.os_manager = OpenStackManager(auth=auth, caller=request.user)
         obj.save()
 
     def delete_model(self, request, obj):
-        # update openstack connection to use this subnet's slice/tenant
-        client = OpenStackClient(tenant=obj.slice.name, **request.session.get('auth', {}))
-        obj.driver = OpenStackDriver(client=client)
-        obj.caller = request.user
+        # update openstack connection to use this site/tenant
+        auth = request.session.get('auth', {})
+        auth['tenant'] = obj.slice.name
+        obj.os_manager = OpenStackManager(auth=auth, caller=request.user)
         obj.delete()
 
 class ImageAdmin(admin.ModelAdmin):
@@ -272,19 +272,18 @@
     list_display = ['ip', 'instance_name', 'name', 'slice', 'numberCores', 'image', 'key', 'node', 'deploymentNetwork']
 
     def save_model(self, request, obj, form, change):
-        # update openstack connection to use this sliver's slice/tenant
-        client = OpenStackClient(tenant=obj.slice.name, **request.session.get('auth', {}))
-        obj.driver = OpenStackDriver(client=client)
-        obj.caller = request.user
+        # update openstack connection to use this site/tenant
+        auth = request.session.get('auth', {})
+        auth['tenant'] = obj.slice.name
+        obj.os_manager = OpenStackManager(auth=auth, caller=request.user)
         obj.save()
 
     def delete_model(self, request, obj):
-        # update openstack connection to use this sliver's slice/tenant
-        client = OpenStackClient(tenant=obj.slice.name, **request.session.get('auth', {}))
-        obj.driver = OpenStackDriver(client=client)
-        obj.caller = request.user
+        # update openstack connection to use this site/tenant
+        auth = request.session.get('auth', {})
+        auth['tenant'] = obj.slice.name
+        obj.os_manager = OpenStackManager(auth=auth, caller=request.user)
         obj.delete()
-     
 
 class UserCreationForm(forms.ModelForm):
     """A form for creating new users. Includes all the required
diff --git a/plstackapi/core/models/sliver.py b/plstackapi/core/models/sliver.py
index a4bf2c0..9a3ca81 100644
--- a/plstackapi/core/models/sliver.py
+++ b/plstackapi/core/models/sliver.py
@@ -29,18 +29,9 @@
         if not self.slice.subnet.exists():
             raise exceptions.ValidationError, "Slice %s has no subnet" % self.slice.name
 
-        if not self.instance_id:
-            instance = self.driver.spawn_instance(name=self.name,
-                                   key_name = self.key.name,
-                                   image_id = self.image.image_id,
-                                   hostname = self.node.name )
-            self.instance_id = instance.id
-            self.instance_name = getattr(instance, 'OS-EXT-SRV-ATTR:instance_name')
-
+        self.os_manager.save_sliver(self)
         super(Sliver, self).save(*args, **kwds)
 
     def delete(self, *args, **kwds):
-        if self.instance_id:
-            self.driver.destroy_instance(self.instance_id)
-
+        self.os_manager.delete_sliver(self)
         super(Sliver, self).delete(*args, **kwds)
diff --git a/plstackapi/core/models/subnet.py b/plstackapi/core/models/subnet.py
index c9ea1ef..be8c938 100644
--- a/plstackapi/core/models/subnet.py
+++ b/plstackapi/core/models/subnet.py
@@ -17,25 +17,9 @@
     def __unicode__(self):  return u'%s' % (self.slice.name)
 
     def save(self, *args, **kwds):
-        if not self.subnet_id:
-            quantum_subnet = self.driver.create_subnet(name= self.slice.name,
-                                          network_id=self.slice.network_id,
-                                          cidr_ip = self.cidr,
-                                          ip_version=self.ip_version,
-                                          start = self.start,
-                                          end = self.end)
-            self.subnet_id = quantum_subnet['id']
-            # add subnet as interface to slice's router
-            self.driver.add_router_interface(self.slice.router_id, self.subnet_id)
-            #add_route = 'route add -net %s dev br-ex gw 10.100.0.5' % self.cidr
-            #commands.getstatusoutput(add_route)
-
+        self.os_manager.save_subnet(self)
         super(Subnet, self).save(*args, **kwds)
 
     def delete(self, *args, **kwds):
-        if self.subnet_id:
-            self.driver.delete_router_interface(self.slice.router_id, self.subnet_id) 
-            self.driver.delete_subnet(self.subnet_id)
-            #del_route = 'route del -net %s' % self.cidr 
-            #commands.getstatusoutput(del_route)
+        self.os_manager.delete_subnet(self)
         super(Subnet, self).delete(*args, **kwds)
diff --git a/plstackapi/openstack/manager.py b/plstackapi/openstack/manager.py
index c0af4ef..e48acc0 100644
--- a/plstackapi/openstack/manager.py
+++ b/plstackapi/openstack/manager.py
@@ -8,12 +8,13 @@
     from plstackapi.core.models import * 
     has_openstack = True
 except:
-    has_openstack = False
+    has_openpstack = False
+
+manager_enabled = Config().api_nova_enabled
 
 def require_enabled(callable):
-    enabled = Config().api_nova_enabled
     def wrapper(*args, **kwds):
-        if enabled and has_openstack:
+        if manager_enabled and has_openstack:
             return callable(*args, **kwds)
         else:
             return None
@@ -23,10 +24,12 @@
 class OpenStackManager:
 
     def __init__(self, auth={}, caller=None):
-        self.client = None
         if auth:
             self.client = OpenStackClient(**auth)
-        
+        else:
+            self.client = OpenStackClient()   
+        self.has_openstack = has_openstack       
+        self.enabled = manager_enabled 
         self.driver = OpenStackDriver(client=self.client) 
         self.caller=caller
 
@@ -130,6 +133,46 @@
             self.driver.delete_network(slice.network_id)
             self.driver.delete_tenant(slice.tenant_id)
 
+    @require_enabled
+    def save_subnet(self, subnet):    
+        if not subnet.subnet_id:
+            quantum_subnet = self.driver.create_subnet(name= subnet.slice.name,
+                                          network_id=subnet.slice.network_id,
+                                          cidr_ip = subnet.cidr,
+                                          ip_version=subnet.ip_version,
+                                          start = subnet.start,
+                                          end = subnet.end)
+            subnet.subnet_id = quantum_subnet['id']
+            # add subnet as interface to slice's router
+            self.driver.add_router_interface(subnet.slice.router_id, subnet.subnet_id)
+            #add_route = 'route add -net %s dev br-ex gw 10.100.0.5' % self.cidr
+            #commands.getstatusoutput(add_route)
+
+    
+    @require_enabled
+    def delete_subnet(self, subnet):
+        if subnet.subnet_id:
+            self.driver.delete_router_interface(subnet.slice.router_id, subnet.subnet_id)
+            self.driver.delete_subnet(subnet.subnet_id)
+            #del_route = 'route del -net %s' % self.cidr
+            #commands.getstatusoutput(del_route)
+    
+    @require_enabled
+    def save_sliver(self, sliver):
+        if not sliver.instance_id:
+            instance = self.driver.spawn_instance(name=sliver.name,
+                                   key_name = sliver.key.name,
+                                   image_id = sliver.image.image_id,
+                                   hostname = sliver.node.name )
+            sliver.instance_id = instance.id
+            sliver.instance_name = getattr(instance, 'OS-EXT-SRV-ATTR:instance_name')
+
+    @require_enabled
+    def delete_sliver(self, sliver):
+        if sliver.instance_id:
+            self.driver.destroy_instance(sliver.instance_id) 
+    
+
     def refresh_nodes(self):
         # collect local nodes
         nodes = Node.objects.all()
diff --git a/plstackapi/openstack/sliveragent.py b/plstackapi/openstack/sliveragent.py
index 732a5f1..f07f603 100644
--- a/plstackapi/openstack/sliveragent.py
+++ b/plstackapi/openstack/sliveragent.py
@@ -1,22 +1,28 @@
 import os
+import sys
 os.environ.setdefault("DJANGO_SETTINGS_MODULE", "plstackapi.planetstack.settings")
 import time
 from plstackapi.core.models.sliver import Sliver
-from plstackapi.openstack.client import OpenStackClient    
+from plstackapi.openstack.manager import OpenStackManager
 
 class SliverAgent:
 
     def run(self):
-        client = OpenStackClient()
-        while True:
+        manager = OpenStackManager()
+        # exit if openstack is disable or unavailable
+        if not manager.enabled or not manager.has_openstack:
+            sys.exit()
+
+        while True :
             # fill in null ip addresses 
             slivers = Sliver.objects.filter(ip=None)
             for sliver in slivers:
                 # update connection
-                client.connect(username=client.keystone.username,
-                               password=client.keystone.password,
+                manager.client.connect(username=manager.client.keystone.username,
+                               password=manager.client.keystone.password,
                                tenant=sliver.slice.name)  
-                servers = client.nova.servers.findall(id=sliver.instance_id)
+                sliver.os_manager = manager
+                servers = manager.client.nova.servers.findall(id=sliver.instance_id)
                 if not servers:
                     continue
                 server = servers[0]