方法一

lsb_release -a

# yum install redhat-lsb -y
# lsb_release -a
LSB 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-noarch
Distributor ID:	CentOS
Description:	CentOS release 6.7 (Final)
Release:	6.7
Codename:	Final

方法二

cat /proc/version

# cat /proc/version
Linux version 2.6.32-573.12.1.el6.x86_64 (mockbuild@c6b8.bsys.dev.centos.org) (gcc version 4.4.7 20120313 (Red Hat 4.4.7-16) (GCC) ) #1 SMP Tue Dec 15 21:19:08 UTC 2015

方法三

uname -a

# uname -a
Linux MyServer321 2.6.32-573.12.1.el6.x86_64 #1 SMP Tue Dec 15 21:19:08 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux

方法四

cat /etc/issue

# cat /etc/issue
CentOS release 6.7 (Final)
Kernel \r on an \m

方法五

cat /etc/redhat-release

# cat /etc/redhat-release
CentOS release 6.7 (Final)