问题：lsb_release 是查看系统版本信息的工具
[root@localhost ~]# lsb_release -a
-bash: lsb_release: command not found
解决方法：yum install redhat-lsb -y
[root@localhost ~]# lsb_release -a
LSB Version: :core-4.0-amd64:core-4.0-noarch:graphics-4.0-amd64:graphics-4.0- noarch:printing-4.0-amd64:printing-4.0-noarch
Distributor ID: CentOS
Description: CentOS Linux release 6.0 (Final)
Release: 6.0
Codename: Final