CentOS7.3升级到CentOS7.9


1)查看当前centos系统版本和内核版本

[root@centos7-82 ~]# cat /etc/redhat-release
CentOS Linux release 7.3.1611 (Core)

   2)备份原来的CentOS-Base.repo [root@centos7-82 ~]# cd /etc/yum.repos.d/ [root@centos7-82 yum.repos.d]# cp CentOS-Base.repo CentOS-Base.repo_bak   3)修改yum源。 要保证更换的yum源地址可以正常访问。如下使用阿里云的yum源http://mirrors.aliyun.com/centos/7.9.2009,要保证手动打开这个地址是有效地址,且镜像yum源内容完整存在。 [base] name=CentOS-$releasever enabled=1 failovermethod=priority baseurl=http://mirrors.aliyun.com/centos/7.9.2009/os/$basearch/ gpgcheck=1 gpgkey=http://mirrors.cloud.aliyuncs.com/centos/RPM-GPG-KEY-CentOS-7 [updates] name=CentOS-$releasever enabled=1 failovermethod=priority baseurl=http://mirrors.aliyun.com/centos/7.9.2009/updates/$basearch/ gpgcheck=1 gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7 [extras] name=CentOS-$releasever enabled=1 failovermethod=priority baseurl=http://mirrors.aliyun.com/centos/7.9.2009/extras/$basearch/ gpgcheck=1 gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7   4)执行更新yum 确保下面更新操作没有报错。 [root@centos7-82  yum.repos.d]# yum update -y   5)重启系统 [root@centos7-82  yum.repos.d]# init 6 重启后查看系统版本

[root@centos7-82 yum.repos.d]# cat /etc/redhat-release
CentOS Linux release 7.9.2009 (Core)