Keepalived PID file /**/**/**//var/run/keepalived.pid not readable (yet?) after start.

Keepalived的安裝過程不說了，就是簡單記錄PID not readable的問題。原因不確認，只是解決方案。
使用的Keepalived版本爲1.3.5
安裝Keepalived後，啓動時發現報錯，使用命令journalctl -xe 查看日誌，其中有此一行：
PID file /var/run/keepalived.pid not readable (yet?) after start.
這是由於沒有按照Keepalived工具默認的路徑配置造成的，解決方法：

1. cp keepalived-1.3.5/keepalived/etc/init.d/keepalived /etc/init.d/
2. mkdir /etc/keepalived
3. cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/
4. cp keepalived-1.3.5/keepalived/etc/sysconfig/keepalived /etc/sysconfig/
5. cp /usr/local/keepalived/sbin/keepalived /usr/local/sbin/
   由於另一項配置需要改正，就是keepalived.service文件中的pid路徑，修改爲默認的路徑即可，/var/run/keepalived.pid