无法执行yum

[root@localhost ~]# yum install kernel-devel
Loaded plugins: fastestmirror
Existing lock /var/run/yum.pid: another copy is running as pid 3703.
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...

这说明系统中已经存在yum,可以强制关掉yum进程：
[root@localhost ~]# rm -f /var/run/yum.pid

 

 

 

ref:http://blog.sina.com.cn/petercnmei