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

 
    有时用yum升级一些文件时，会出现以下情况：

          another app is currently holding the yum lock;waiting for it to exit...
 
    可以通过强制关掉yum进程：

         #rm -f /var/run/yum.pid
 
    然后就可以使用yum了。