diff --git a/gns3server/modules/virtualbox/__init__.py b/gns3server/modules/virtualbox/__init__.py
index a6440072..04df958f 100644
--- a/gns3server/modules/virtualbox/__init__.py
+++ b/gns3server/modules/virtualbox/__init__.py
@@ -133,6 +133,7 @@ class VirtualBox(BaseManager):
             if not extra_data[0].strip() == "Value: yes":
                 # get the amount of RAM
                 info_results = yield from self.execute("showvminfo", [vmname, "--machinereadable"])
+                ram = 0
                 for info in info_results:
                     try:
                         name, value = info.split('=', 1)
diff --git a/gns3server/modules/virtualbox/virtualbox_vm.py b/gns3server/modules/virtualbox/virtualbox_vm.py
index 1c9b5ce2..905a2edc 100644
--- a/gns3server/modules/virtualbox/virtualbox_vm.py
+++ b/gns3server/modules/virtualbox/virtualbox_vm.py
@@ -209,7 +209,7 @@ class VirtualBoxVM(BaseVM):
             log.info("VirtualBox VM '{name}' [{id}] stopped".format(name=self.name, id=self.id))
             log.debug("Stop result: {}".format(result))
 
-            yield from asyncio.sleep(0.5)  # give some time for VirtualBox to unlock the VM
+            # yield from asyncio.sleep(0.5)  # give some time for VirtualBox to unlock the VM
             try:
                 # deactivate the first serial port
                 yield from self._modify_vm("--uart1 off")