Yum 版本库管理

 1# 备份原镜像文件，以免出错后可以恢复。
 2$ mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup \
 3&& mv /etc/yum.repos.d/epel.repo /etc/yum.repos.d/epel.repo.backup \
 4&& mv /etc/yum.repos.d/epel-testing.repo /etc/yum.repos.d/epel-testing.repo.backup
 5
 6# 下载新的CentOS-Base.repo 到/etc/yum.repos.d/
 7$ curl -o /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo \
 8&& curl -o /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-7.repo \
 9&& curl -o /etc/yum.repos.d/epel-testing.repo http://mirrors.aliyun.com/repo/epel-testing.repo
10
11# 运行yum makecache生成缓存
12$ yum clean all && yum makecache

1$ yum list installed

1# 升级所有包同时也升级软件和系统内核
2$ yum -y update
3
4# 只升级所有包，不升级软件和系统内核
5$ yum -y upgrade

1$ yum repolist
2# 显示所有仓库
3$ yum repolist all
4# 显示所有启动的仓库
5$ yum repolist enabled
6# 显示所有禁用的仓库
7$ yum repolist disabled

1$ yum-config-manager --enable repository…
2$ yum-config-manager --disable repository…