2-2-4-5 4.x ---> 5.x 升級版本

4.x ---> 5.x 參考下列連結由 4.4 升級至 5.x

https://pve.proxmox.com/wiki/Package_Repositories#_proxmox_ve_no_subscription_repository

# wget http://download.proxmox.com/debian/proxmox-ve-release-5.x.gpg -O /etc/apt/trusted.gpg.d/proxmox-ve-release-5.x.gpg

修改套件來源
將 /etc/apt/sources.list 檔的內容變更為如下
# pico /etc/apt/sources.list

deb http://ftp.debian.org/debian stretch main contrib

# PVE pve-no-subscription repository provided by proxmox.com,
# NOT recommended for production use
deb http://download.proxmox.com/debian/pve stretch pve-no-subscription
# security updates
deb http://security.debian.org stretch/updates main contrib

# 這一行是測試版本，不建議使用在正式產品運作上
deb http://download.proxmox.com/debian/pve stretch pvetest

更新套件庫資料

# apt-get update

更新套件

# apt-get dist-upgrade

更新完成後 Proxmox VE 已經升級到 5.x 版
但 OS debian 並未升級至 9.x 版