1.centos查看是 centos几的
    cat /etc/redhat-release

    1. [root@91centos91 Tool]# cat /etc/redhat-release
    2. CentOS Linux release 7.8.2003 (Core)

    2.查看内核版本

    1. [root@91centos91 Tool]# cat /proc/version
    2. Linux version 3.10.0-1127.el7.x86_64 (mockbuild@kbuilder.bsys.centos.org) (gcc version 4.8.5 20150623 (Red Hat 4.8.5-39) (GCC) ) #1 SMP Tue Mar 31 23:36:51 UTC 2020