解决pve6.2/pve6.3 安装ifupdown2,失败问题

1. 替换国内debian源 --可选

echo "deb http://mirrors.aliyun.com/debian/ buster main non-free contrib
deb-src http://mirrors.aliyun.com/debian/ buster main non-free contrib
deb http://mirrors.aliyun.com/debian-security buster/updates main
deb-src http://mirrors.aliyun.com/debian-security buster/updates main
deb http://mirrors.aliyun.com/debian/ buster-updates main non-free contrib
deb-src http://mirrors.aliyun.com/debian/ buster-updates main non-free contrib
deb http://mirrors.aliyun.com/debian/ buster-backports main non-free contrib
deb-src http://mirrors.aliyun.com/debian/ buster-backports main non-free contrib" > /etc/apt/sources.list

2. 删除企业订阅
   rm /etc/apt/sources.list.d/pve-enterprise.list

3. 配置非订阅免费源
   echo "deb https://mirrors.ustc.edu.cn/proxmox/debian/pve/ buster pve-no-subscription " >/etc/apt/sources.list.d/pve-install-repo.list

4. 安装必要的包 ifupdown2,openvswitch-switch

apt update
apt install ifupdown2 openvswitch-switch -y