解决Another app is currently holding the yum lock; waiting for it to exit...

[root@bogon ~]# yum install gcc-c++
Loaded plugins: fastestmirror, refresh-packagekit, security
Existing lock /var/run/yum.pid: another copy is running as pid 2395.
Another app is currently holding the yum lock; waiting for it to exit...
The other application is: PackageKit
Memory :  20 M RSS ( 35 MB VSZ)
Started: Thu Jul 20 11:25:58 2017 - 8:01:01 ago
State  : Sleeping, pid: 2395

这里的意思是yum被占用所以需要把这个进程干掉！！！

解决办法：

第一种办法：

kill -s 9 2395

第二种办法：

要是第一种没效果就用下面语句：

rm -f /var/run/yum.pid

然后使用ps命令

ps aux|grep yum

查看占用yum的进程是否被干掉

然后安心的使用yum命令吧。。。我这里安装的是gcc

yum install gcc-c++