version 1 から 2へ上げる手順
apt update
apt dist-upgrade
sed -i 's/buster\/updates/bullseye-security/g;s/buster/bullseye/g' \
/etc/apt/sources.list
echo "deb http://download.proxmox.com/debian/pbs bullseye pbs-no-subscription" \
> /etc/apt/sources.list.d/pbs-enterprise.list
sed -i 's/buster/bullseye/g' /etc/apt/sources.list.d/pbs-repo.list
apt update
systemctl stop proxmox-backup-proxy.service proxmox-backup.service
apt update
apt dist-upgrade
reboot