yum lock的解决办法

错误提示:

[root@localhost wangcheng]# yum install yumex
Existing lock /var/run/yum.pid: another copy is running as pid 3807.
Another app is currently holding the yum lock; waiting for it to exit...
Another app is currently holding the yum lock; waiting for it to exit...
Another app is currently holding the yum lock; waiting for it to exit...
Another app is currently holding the yum lock; waiting for it to exit...
Another app is currently holding the yum lock; waiting for it to exit...
Another app is currently holding the yum lock; waiting for it to exit...
Another app is currently holding the yum lock; waiting for it to exit...
Another app is currently holding the yum lock; waiting for it to exit...
Another app is currently holding the yum lock; waiting for it to exit...
Another app is currently holding the yum lock; waiting for it to exit...

可能是系统自动升级正在运行,所以yum被锁定了.
可以通过执行

rm -rf /var/run/yum.pid

来强行解除锁定,然后你的yum就可以运行了