刚学习，安装的时候报错：
[root@iZ2~]# uname -a
Linux iZ2801trzi8Z 3.10.0-123.9.3.el7.x86_64 #1 SMP Thu Nov 6 15:06:03 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux
在运行yum -y install docker时最后说文件有冲突，怎么解决啊？谢谢谢谢。
Running transaction check
Running transaction test
Transaction check error:
file /usr/lib/systemd/system/blk-availability.service from install of device-mapper-7:1.02.107-5.el7.x86_64 conflicts with file from package lvm2-7:2.02.105-14.el7.x86_64
file /usr/sbin/blkdeactivate from install of device-mapper-7:1.02.107-5.el7.x86_64 conflicts with file from package lvm2-7:2.02.105-14.el7.x86_64
file /usr/share/man/man8/blkdeactivate.8.gz from install of device-mapper-7:1.02.107-5.el7.x86_64 conflicts with file from package lvm2-7:2.02.105-14.el7.x86_64
Error Summary
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我查到一个文章解决了这个问题：http://blog.csdn.net/beer_do/article/details/50469008
自测下来，先安装 lvm2，然后再装 docker 既可以解决问题：
yum install lvm2
yum install docker