Built two Ubuntu 18.04 servers and then followed: https://www.howtoforge.com/tutorial...abase-cluster-on-debian-8.4-with-ispconfig-3/ There was a comment from Till about copying /usr/local/ispconfig/interface/lib/config.inc.php from master to the slave server, which I have done and now have access to the management interface on both. I think I also concluded that step 5.5 may be optional, so haven't done it. I could be wrong however. Pretty much everything seems to be working [after I created a cron job to sync /etc/letsencrypt/] but there is one step on the install which doesn't work - "If you have already data (Websites, Mail....) running on server1, go to Tools / Resync and start a full resync (enable all checkboxes).". I only ever see the master server in the dropdown so can't run a resync to the slave. I have tried doing an "update" and re-doing a few steps but it hasn't made any difference. MySQL clustering is working fine.