=== modified file 'cloudinit/cs_utils.py'
--- cloudinit/cs_utils.py	2014-02-12 10:14:49 +0000
+++ cloudinit/cs_utils.py	2014-05-26 20:03:06 +0000
@@ -35,6 +35,7 @@
 
 import serial
 
+DEF_TIMEOUT = 5
 SERIAL_PORT = '/dev/ttyS1'
 if platform.system() == 'Windows':
     SERIAL_PORT = 'COM2'
@@ -76,8 +77,9 @@
         self.result = self._marshal(self.raw_result)
 
     def _execute(self):
-        connection = serial.Serial(SERIAL_PORT)
-        connection.write(self.request)
+        connection = serial.Serial(SERIAL_PORT, timeout=DEF_TIMEOUT,
+                                   writeTimeout=DEF_TIMEOUT)
+        connection.write(self.request, )
         return connection.readline().strip('\x04\n')
 
     def _marshal(self, raw_result):