Centos Another app is currently holding the yum lock

yum命令用ctrl+z命令中断后，再运行yum时，出现：

Existing lock /var/run/yum.pid: another copy is running as pid 3046.
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...

解决方案：

rm -f /var/run/yum.pid

/sbin/service yum-updatesd restart

Stopping yum-updatesd:                                     [ OK ]
Starting yum-updatesd:                                     [ OK ]

yum-updatesd上系统自带的一个提供系统更新的服务，安装文件也叫做yum-updatesd，这个服务默认是自动启动的（init 5），因为系统只允许一个更新进程在运行，所以他运行的时候会自动给yum加锁，这就导致了开机后不能手动进行yum了。