1. 备份原有源配置
mkdir /etc/yum.repos.d/backup
mv /etc/yum.repos.d/*.repo /etc/yum.repos.d/backup/
2. 设置阿里云镜像源
cat > /etc/yum.repos.d/CentOS-Base.repo << 'EOF'
# CentOS-Base.repo
#
# 阿里云镜像源
#
[base]
name=CentOS-$releasever - Base
baseurl=https://mirrors.aliyun.com/centos-vault/8.2.2004/BaseOS/$basearch/os/
gpgcheck=1
gpgkey=https://mirrors.aliyun.com/centos-vault/RPM-GPG-KEY-CentOS-Official
[updates]
name=CentOS-$releasever - Updates
baseurl=https://mirrors.aliyun.com/centos-vault/8.2.2004/BaseOS/$basearch/os/
gpgcheck=1
gpgkey=https://mirrors.aliyun.com/centos-vault/RPM-GPG-KEY-CentOS-Official
[extras]
name=CentOS-$releasever - Extras
baseurl=https://mirrors.aliyun.com/centos-vault/8.2.2004/extras/$basearch/os/
gpgcheck=1
gpgkey=https://mirrors.aliyun.com/centos-vault/RPM-GPG-KEY-CentOS-Official
[centosplus]
name=CentOS-$releasever - Plus
baseurl=https://mirrors.aliyun.com/centos-vault/8.2.2004/centosplus/$basearch/os/
gpgcheck=1
enabled=0
gpgkey=https://mirrors.aliyun.com/centos-vault/RPM-GPG-KEY-CentOS-Official
[PowerTools]
name=CentOS-$releasever - PowerTools
baseurl=https://mirrors.aliyun.com/centos-vault/8.2.2004/PowerTools/$basearch/os/
gpgcheck=1
enabled=0
gpgkey=https://mirrors.aliyun.com/centos-vault/RPM-GPG-KEY-CentOS-Official
[AppStream]
name=CentOS-$releasever - AppStream
baseurl=https://mirrors.aliyun.com/centos-vault/8.2.2004/AppStream/$basearch/os/
gpgcheck=1
gpgkey=https://mirrors.aliyun.com/centos-vault/RPM-GPG-KEY-CentOS-Official
EOF
3. 清除缓存并更新
yum clean all
yum makecache
yum update -y