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

刚安装完虚拟机，用xshell连接上linux后，安装程序时一直出现这个信息Another app is currently holding the yum lock; waiting for it to exit...

解决方法：
rm -rf /var/run/yum.pid 来强行解除锁定，然后你的yum就可以运行了

可以看博文

http://www.cnblogs.com/IceKernel/articles/2587274.html