short: The admin with enough xp is ill, there is no one with xp with varnish is and after 1 restart varnish outputs only 503.
long: there original admin is ill but he gave me an project to migrate an typo3 installation to a new server. Thats ok.
Plan: I move 150 GB of data with rsync to the new server, let specialists do something and switch ips between the new and old and clear varnish with a restart.
Reality: +2 hours to migrate the data, because of false infos from the admin, 7 hours preparing the switch, 5 minutes switch, 3 hours to find out the F*****G varnish is the single point of failure. I and the t3 guys agree to see the next day what went wrong.

ALL HAPPENED TODAY!

Plan for tomorrow: speak with the boss to account the extra hours to that day so i dont get over 10 hours and debug that fucking varnish and delete some servers from another project from the backupsystem and monitoring.