用yum安装软件提示的解决方法：
[root@centosf2 beauty]# yum install gcc
Loaded plugins: fastestmirror
Existing lock /var/run/yum.pid: another copy is running as pid 1479.
Another app is currently holding the yum lock; waiting for it to exit...
The other application is: yum
Memory : 55 M RSS (355 MB VSZ)
Started: Thu Oct 30 12:40:56 2014 - 1:17:37 ago
State : Sleeping, pid: 1479
Another app is currently holding the yum lock; waiting for it to exit...
The other application is: yum
Memory : 55 M RSS (355 MB VSZ)
Started: Thu Oct 30 12:40:56 2014 - 1:17:39 ago
State : Sleeping, pid: 1479
Another app is currently holding the yum lock; waiting for it to exit...
The other application is: yum
Memory : 55 M RSS (355 MB VSZ)
Started: Thu Oct 30 12:40:56 2014 - 1:17:41 ago
State : Sleeping, pid: 1479
这是由于锁定了yum，使用rm -rf /var/run/yum.pid来解锁就OK了
Another app is currently holding the yum lock; waiting for it to exit
原文：http://vqiao.blog.51cto.com/9368913/1575036