1、使用lsb_release -a命令查看
[root@centos6 ~]# lsb_release -aLSB Version: :base-4.0-amd64:base-4.0-noarch:core-4.0-amd64:core-4.0-noarch:graphics-4.0-amd64:graphics-4.0-noarch:printing-4.0-amd64:printing-4.0-noarchDistributor ID: CentOSDescription: CentOS release 6.9 (Final)Release: 6.9Codename: Final但是，centos7.3里没有lsb_release命令。
2、使用cat /etc/os-release命令打开文件查看
[root@centos7 app]# cat /etc/os-release NAME="CentOS Linux"VERSION="7 (Core)"ID="centos"ID_LIKE="rhel fedora"VERSION_ID="7"PRETTY_NAME="CentOS Linux 7 (Core)"ANSI_COLOR="0;31"CPE_NAME="cpe:/o:centos:centos:7"HOME_URL="https://www.centos.org/"BUG_REPORT_URL="https://bugs.centos.org/" CENTOS_MANTISBT_PROJECT="CentOS-7"CENTOS_MANTISBT_PROJECT_VERSION="7"REDHAT_SUPPORT_PRODUCT="centos"REDHAT_SUPPORT_PRODUCT_VERSION="7"3、使用cat /etc/redhat-release（/etc/centos-release）命令查看
[root@centos6 ~]# cat /etc/redhat-release CentOS release 6.9 (Final)[root@centos7 app]# cat /etc/redhat-release CentOS Linux release 7.3.1611 (Core)4、使用rpm -q centos-release命令查看
[root@centos6 ~]# rpm -q centos-releasecentos-release-6-9.el6.12.3.x86_64[root@centos7 app]# rpm -q centos-releasecentos-release-7-3.1611.el7.centos.x86_64