==== PVE 5 =====
    - <code h /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
</code>
    - <code h /etc/apt/sources.list.d/pve-enterprise.list>
#deb https://enterprise.proxmox.com/debian/pve stretch pve-enterprise
</code>