SaltStack minion故障解决： salt-minion dead but pid file exists (转)

说明：
　　看了网上很多关于alt-minion dead but pid file exists 的解决方法，千篇一律的写一个shell脚本 killproc salt-minion
见链接：http://732233048.blog.51cto.com/9323668/1693483
但是并没有什么用，我如何解决这个问题的呢，请容我慢慢道来。
系统版本：CentOS_6.7_64bit 环境已优化。
重装（第一次装）salt-minion，但是客户端却无法正常启动，如下报错：

[root@namenode ~]# /etc/init.d/salt-minion status
salt-minion dead but pid file exists

解决过程：
由报错知：
minion进程已经死，但是进程文件还在
于是去找进程文件，在minion机的配置文件里/etc/init.d/salt-minion里发现进程文件是：
/var/run/salt-minion.pid
然后尝试把进程文件删掉，再重新启动：

[root@namenode ~]# /etc/init.d/salt-minion restart
Stopping salt-minion daemon: [FAILED]
Starting salt-minion daemon: [ OK ]
[root@namenode ~]# /etc/init.d/salt-minion status
salt-minion dead but pid file exists

仍然没有解决问题。
不要着急，debug一下：

[root@namenode ~]salt-minion -l debug
[INFO ] Setting up the Salt Minion "namenode"
[DEBUG ] Created pidfile: /var/run/salt-minion.pid
[DEBUG ] Reading configuration from /etc/salt/minion
[DEBUG ] Attempting to authenticate with the Salt Master at 192.168.1.53
[DEBUG ] Initializing new SAuth for ('/etc/salt/pki/minion', 'namenode', 'tcp://192.168.1.53:4506')
[ERROR ] The master key has changed, the salt master could have been subverted, verify salt master's public key
[CRITICAL] The Salt Master server's public key did not authenticate!
The master may need to be updated if it is a version of Salt lower than 2015.5.5, or
If you are confident that you are connecting to a valid Salt Master, then remove the master public key and restart the Salt Minion.
The master public key can be found at:
/etc/salt/pki/minion/minion_master.pub

查看salt-minion日志 ：

[root@namenode ~]less /var/log/salt/minion
也发现同样的错误：
2015-12-15 16:35:06,519 [salt.crypt][CRITICAL][12704] The Salt Master server's public key did not authenticate!
10647 The master may need to be updated if it is a version of Salt lower than 2015.5.5, or
10648 If you are confident that you are connecting to a valid Salt Master, then remove the master public key and restart the Salt Minion.
10649 The master public key can be found at:
10650 /etc/salt/pki/minion/minion_master.pub

解决方法：
直接在客户端上来上一条

[root@namenode ~]# rm -rf /etc/salt/pki/minion/minion_master.pub
[root@namenode ~]/etc/init.d/salt-minion restart