diff --git a/src/mad/ruby/VirtualMachineDriver.rb b/src/mad/ruby/VirtualMachineDriver.rb
index 0d3909d220..e97105d167 100644
--- a/src/mad/ruby/VirtualMachineDriver.rb
+++ b/src/mad/ruby/VirtualMachineDriver.rb
@@ -50,6 +50,7 @@ class VirtualMachineDriver < OpenNebulaDriver
         :attach_nic  => "ATTACHNIC",
         :detach_nic  => "DETACHNIC",
         :disk_snapshot_create => "DISKSNAPSHOTCREATE",
+        :resize_disk => "RESIZEDISK",
         :update_sg   => "UPDATESG"
     }
 
@@ -93,6 +94,7 @@ class VirtualMachineDriver < OpenNebulaDriver
         register_action(ACTION[:attach_nic].to_sym, method("attach_nic"))
         register_action(ACTION[:detach_nic].to_sym, method("detach_nic"))
         register_action(ACTION[:disk_snapshot_create].to_sym, method("disk_snapshot_create"))
+        register_action(ACTION[:resize_disk].to_sym, method("resize_disk"))
         register_action(ACTION[:update_sg].to_sym, method("update_sg"))
     end
 
@@ -203,6 +205,11 @@ class VirtualMachineDriver < OpenNebulaDriver
         send_message(ACTION[:disk_snapshot_create],RESULT[:failure],id,error)
     end
 
+    def resize_disk(id, drv_message)
+        error = "Action not implemented by driver #{self.class}"
+        send_message(ACTION[:resize_disk],RESULT[:failure],id,error)
+    end
+
     def update_sg(id, drv_message)
         error = "Action not implemented by driver #{self.class}"
         send_message(ACTION[:update_sg],RESULT[:failure],id,error)
diff --git a/src/vmm_mad/exec/one_vmm_exec.rb b/src/vmm_mad/exec/one_vmm_exec.rb
index 9e84bcfca8..909ada6d5b 100755
--- a/src/vmm_mad/exec/one_vmm_exec.rb
+++ b/src/vmm_mad/exec/one_vmm_exec.rb
@@ -780,6 +780,43 @@ class ExecDriver < VirtualMachineDriver
                     :script_name => "snapshot_delete")
     end
 
+    #
+    # RESIZEDISK action, resizes a disk on a running VM
+    #
+    def resize_disk(id, drv_message)
+        action   = ACTION[:resize_disk]
+        xml_data = decode(drv_message)
+
+        tm_command = ensure_xpath(xml_data, id, action, 'TM_COMMAND') || return
+
+        size = xml_data.elements['SIZE'].text.strip
+        disk_id = xml_data.elements['DISK_ID'].text.strip
+
+        action = VmmAction.new(self, id, :resize_disk, drv_message)
+
+        steps = [
+            # Perform a PROLOG on the disk
+            {
+                :driver     => :tm,
+                :action     => :tm_resize,
+                :parameters => tm_command.split
+            },
+            # Run the attach vmm script
+            {
+                :driver       => :vmm,
+                :action       => :resize_disk,
+                :parameters   => [
+                        :deploy_id,
+                        disk_id,
+                        size,
+                        drv_message,
+                        :host
+                ]
+            }
+        ]
+
+        action.run(steps)
+    end
     #
     # CLEANUP action, frees resources allocated in a host: VM and disk images
     #