当我运行 yum 命令安装程序时提示如下错误：
Loaded plugins: fastestmirror
Existing lock /var/run/yum.pid: another copy is running as pid 32522.
Another app is currently holding the yum lock; waiting for it to exit…
The other application is: yum
Memory : 66 M RSS (943 MB VSZ)
Started: Mon Aug 8 13:34:16 2016 – 36:10 ago
State : Traced/Stopped, pid: 32522
通过以下命令找到yum程序id：
ps aux | grep yum
解决办法1：
kill -9 32522
解决办法2：
rm -f /var/run/yum.pid 32522