CENTOS 8.0 更新 阿里源

# 1. 备份并清空旧源
cd /etc/yum.repos.d/
mkdir -p backup_repo
mv *.repo backup_repo/ 2>/dev/null

# 2. 下载阿里云 Vault 源
wget -O /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-vault-8.5.2111.repo

# 3. 下载 EPEL 源 (可选)
wget -O /etc/yum.repos.d/epel.repo https://mirrors.aliyun.com/repo/epel-archive-8.repo

# 4. 清理并重建缓存
yum clean all
yum makecache

# 5. 测试更新
yum update -y