网络是通的,但问题是CentOS官方镜像站点可能已经停止服务了(CentOS 7已EOL)。需要更换yum源。
打开CentOS-Base.repo
sudo vi /etc/yum.repos.d/CentOS-Base.repo
内容全部替换
[base]
name=CentOS-$releasever - Base
baseurl=http://mirrors.aliyun.com/centos/$releasever/os/$basearch/
http://mirrors.tuna.tsinghua.edu.cn/centos/$releasever/os/$basearch/
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
[updates]
name=CentOS-$releasever - Updates
baseurl=http://mirrors.aliyun.com/centos/$releasever/updates/$basearch/
http://mirrors.tuna.tsinghua.edu.cn/centos/$releasever/updates/$basearch/
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
[extras]
name=CentOS-$releasever - Extras
baseurl=http://mirrors.aliyun.com/centos/$releasever/extras/$basearch/
http://mirrors.tuna.tsinghua.edu.cn/centos/$releasever/extras/$basearch/
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
[centosplus]
name=CentOS-$releasever - Plus
baseurl=http://mirrors.aliyun.com/centos/$releasever/centosplus/$basearch/
http://mirrors.tuna.tsinghua.edu.cn/centos/$releasever/centosplus/$basearch/
gpgcheck=1
enabled=0
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
#contrib - packages by Centos Users
[contrib]
name=CentOS-$releasever - Contrib
baseurl=http://mirrors.aliyun.com/centos/$releasever/contrib/$basearch/
http://mirrors.tuna.tsinghua.edu.cn/centos/$releasever/contrib/$basearch/
gpgcheck=1
enabled=0
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
failovermethod=roundrobin
清理缓存
sudo yum clean all
sudo yum makecache
sudo yum update