title: Minion did not return. [Not connected] when execute: salt 'minion1' test.ping
body: <p>The question for the similar issue may have been asked for many times in stackoverflow. However after searching, I found no answer solve my problem. So I post it here to seek for your help.</p>
  
  <p>My system is Ubuntu 14.04. After setup master and minion (named "minion1"), I test salt on master using the command</p>
  
  <pre><code>salt 'minion1' test.ping
  </code></pre>
  
  <p>I got the following error:</p>
  
  <pre><code>minion1:
      Minion did not return. [Not connected]
  </code></pre>
  
  <p>Following others' advices, I have tested the following commands:</p>
  
  <ol>
  <li><p>On minion, I firstly remove the previous master key by:</p>
  
  <p><code>rm /etc/salt/pki/minion/minion_master.pub</code></p></li>
  </ol>
  
  <p>and restart minion, but still failed. So we eliminate the case of unmatched master key.</p>
  
  <ol start="2">
  <li><p>On minion, I execute</p>
  
  <p><code>salt-call test.ping</code></p></li>
  </ol>
  
  <p>to get:</p>
  
  <pre><code>local:
      True
  </code></pre>
  
  <p>so the communication between master and minion is good.</p>
  
  <ol start="3">
  <li><p>On minion, I firstly stop salt-minion using command:</p>
  
  <p><code>service salt-minion stop</code> </p></li>
  </ol>
  
  <p>and run it in debug mode using command:</p>
  
  <pre><code>salt-minion -l debug
  </code></pre>
  
  <p>to get the following return:</p>
  
  <pre><code>[DEBUG   ] Reading configuration from /etc/salt/minion
  [INFO    ] Using cached minion ID from /etc/salt/minion_id: minion1
  [DEBUG   ] loading log_handlers in ['/var/cache/salt/minion/extmods/log_handlers', '/usr/lib/python2.7/dist-packages/salt/log/handlers']
  [DEBUG   ] Skipping /var/cache/salt/minion/extmods/log_handlers, it is not a directory
  [DEBUG   ] Configuration file path: /etc/salt/minion
  [INFO    ] Setting up the Salt Minion "minion1"
  [DEBUG   ] Created pidfile: /var/run/salt-minion.pid
  [DEBUG   ] Chowned pidfile: /var/run/salt-minion.pid to user: root
  [DEBUG   ] Reading configuration from /etc/salt/minion
  [DEBUG   ] loading grain in ['/var/cache/salt/minion/extmods/grains', '/usr/lib/python2.7/dist-packages/salt/grains']
  [DEBUG   ] Skipping /var/cache/salt/minion/extmods/grains, it is not a directory
  [DEBUG   ] Attempting to authenticate with the Salt Master at 192.168.0.101
  [DEBUG   ] Loaded minion key: /etc/salt/pki/minion/minion.pem
  [DEBUG   ] Loaded minion key: /etc/salt/pki/minion/minion.pem
  [DEBUG   ] Decrypting the current master AES key
  [DEBUG   ] Loaded minion key: /etc/salt/pki/minion/minion.pem
  [INFO    ] Authentication with master successful!
  [DEBUG   ] Loaded minion key: /etc/salt/pki/minion/minion.pem
  [DEBUG   ] Decrypting the current master AES key
  [DEBUG   ] Loaded minion key: /etc/salt/pki/minion/minion.pem
  [DEBUG   ] Loaded minion key: /etc/salt/pki/minion/minion.pem
  [DEBUG   ] Reading configuration from /etc/salt/minion
  [DEBUG   ] loading grain in ['/var/cache/salt/minion/extmods/grains', '/usr/lib/python2.7/dist-packages/salt/grains']
  [DEBUG   ] Skipping /var/cache/salt/minion/extmods/grains, it is not a directory
  [DEBUG   ] loading module in ['/var/cache/salt/minion/extmods/modules', '/usr/lib/python2.7/dist-packages/salt/modules']
  [DEBUG   ] Skipping /var/cache/salt/minion/extmods/modules, it is not a directory
  [DEBUG   ] Loaded localemod as virtual locale
  [DEBUG   ] Loaded groupadd as virtual group
  [DEBUG   ] Loaded linux_sysctl as virtual sysctl
  [DEBUG   ] Loaded parted as virtual partition
  [DEBUG   ] Loaded linux_acl as virtual acl
  [DEBUG   ] Loaded apt as virtual pkg
  [DEBUG   ] Loaded sysmod as virtual sys
  [DEBUG   ] Loaded djangomod as virtual django
  [DEBUG   ] Loaded upstart as virtual service
  [DEBUG   ] Loaded useradd as virtual user
  [DEBUG   ] Loaded dpkg as virtual lowpkg
  [DEBUG   ] Loaded debconfmod as virtual debconf
  [DEBUG   ] Loaded virtualenv_mod as virtual virtualenv
  [DEBUG   ] Loaded cmdmod as virtual cmd
  [DEBUG   ] loading returner in ['/var/cache/salt/minion/extmods/returners', '/usr/lib/python2.7/dist-packages/salt/returners']
  [DEBUG   ] Skipping /var/cache/salt/minion/extmods/returners, it is not a directory
  [DEBUG   ] Loaded syslog_return as virtual syslog
  [DEBUG   ] Loaded couchdb_return as virtual couchdb
  [DEBUG   ] Loaded carbon_return as virtual carbon
  [DEBUG   ] Loaded sqlite3_return as virtual sqlite3
  [ERROR   ] An un-handled exception was caught by salt's global exception handler:
  UnpackValueError: 
  Traceback (most recent call last):
    File "/usr/bin/salt-minion", line 14, in &lt;module&gt;
      salt_minion()
    File "/usr/lib/python2.7/dist-packages/salt/scripts.py", line 30, in salt_minion
      minion.start()
    File "/usr/lib/python2.7/dist-packages/salt/__init__.py", line 219, in start
      self.prepare()
    File "/usr/lib/python2.7/dist-packages/salt/__init__.py", line 207, in prepare
      self.minion = salt.minion.Minion(self.config)
    File "/usr/lib/python2.7/dist-packages/salt/minion.py", line 518, in __init__
  self.returners)
    File "/usr/lib/python2.7/dist-packages/salt/utils/schedule.py", line 71, in __init__
      clean_proc_dir(opts)
    File "/usr/lib/python2.7/dist-packages/salt/utils/schedule.py", line 267, in clean_proc_dir
      job = salt.payload.Serial(opts).load(fp_)
    File "/usr/lib/python2.7/dist-packages/salt/payload.py", line 108, in load
      return self.loads(data)
    File "/usr/lib/python2.7/dist-packages/salt/payload.py", line 95, in loads
      return msgpack.loads(msg, use_list=True)
    File "_unpacker.pyx", line 119, in msgpack._unpacker.unpackb (msgpack/_unpacker.cpp:119)
  UnpackValueError
  Traceback (most recent call last):
    File "/usr/bin/salt-minion", line 14, in &lt;module&gt;
      salt_minion()
    File "/usr/lib/python2.7/dist-packages/salt/scripts.py", line 30, in salt_minion
      minion.start()
    File "/usr/lib/python2.7/dist-packages/salt/__init__.py", line 219, in start
      self.prepare()
    File "/usr/lib/python2.7/dist-packages/salt/__init__.py", line 207, in prepare
      self.minion = salt.minion.Minion(self.config)
    File "/usr/lib/python2.7/dist-packages/salt/minion.py", line 518, in __init__
  self.returners)
    File "/usr/lib/python2.7/dist-packages/salt/utils/schedule.py", line 71, in __init__
      clean_proc_dir(opts)
    File "/usr/lib/python2.7/dist-packages/salt/utils/schedule.py", line 267, in clean_proc_dir
      job = salt.payload.Serial(opts).load(fp_)
    File "/usr/lib/python2.7/dist-packages/salt/payload.py", line 108, in load
      return self.loads(data)
    File "/usr/lib/python2.7/dist-packages/salt/payload.py", line 95, in loads
      return msgpack.loads(msg, use_list=True)
    File "_unpacker.pyx", line 119, in msgpack._unpacker.unpackb (msgpack/_unpacker.cpp:119)
  msgpack.exceptions.UnpackValueError
  </code></pre>
  
  <p>This problem has being hanging there for some time, could anyone help me on that? Thanks in advance!</p>
  
  <p><strong>Edit:</strong></p>
  
  <p>I found a strange thing after the before post. When I run the command </p>
  
  <pre><code>service salt-minion status
  </code></pre>
  
  <p>Oddly enough it returned:</p>
  
  <pre><code>salt-minion stop/waiting
  </code></pre>
  
  <p>if I further check using: <code>ps aux| grep salt-minion</code>, I found no process of salt-minion is running. I wonder that's why <code>salt minion1 test.ping</code> cannot return correct value. However, no matter what I did (<code>service salt-minion start</code>), I could never make the return of <code>service salt-minion status</code> shows salt-minion is start/running. What should I do now?</p>