linux 查看系统版本

几种查看linux版本信息的方法：
uname -a
cat /proc/version
cat /etc/issue
lsb_release -a
详解 lsb_release -a
登录到服务器执行 lsb_release -a ，即可列出所有版本信息，例如：
[[email protected] ~]# lsb_release -a   
LSB Version: 1.3   
Distributor ID: RedHatEnterpriseAS   
Description: Red Hat Enterprise Linux AS release 4 (Nahant Update 1)   
Release: 4   
Codename: NahantUpdate1   
[[email protected] ~]# 
这个命令适用于所有的linux，包括Redhat、SuSE、Debian等发行版。
登录到linux执行cat /etc/redhat-release ，例如如下：
[[email protected] ~]# cat /etc/redhat-release   
Red Hat Enterprise Linux AS release 4 (Nahant Update 1)   
[[email protected] ~]# 
这种方式下可以直接看到具体的版本号，比如 AS4 Update 1
登录到linux执行rpm -q redhat-release ，例如如下
[[email protected] ~]# rpm -q redhat-release   
redhat-release-4AS-2.4   
[[email protected] ~]# 
这种方式下可看到一个所谓的release号，比如上边的例子是2.4
这个release号和实际的版本之间存在一定的对应关系，如下：
redhat-release-3AS-1 -> Redhat Enterprise Linux AS 3   
redhat-release-3AS-7.4 -> Redhat Enterprise Linux AS 3 Update 4   
redhat-release-4AS-2 -> Redhat Enterprise Linux AS 4   
redhat-release-4AS-2.4 -> Redhat Enterprise Linux AS 4 Update 1   
redhat-release-4AS-3 -> Redhat Enterprise Linux AS 4 Update 2   
redhat-release-4AS-4.1 -> Redhat Enterprise Linux AS 4 Update 3   
redhat-release-4AS-5.5 -> Redhat Enterprise Linux AS 4 Update 4 
注意：第2、3两种方法只对Redhat Linux有效