After a few tests, we realised that our cloud init templates for our web servers were configured and adapted incorrectly.
As a result, some network crashes occur, incorrect cache values are written to RAM and some Plesk settings are not applied to the server itself.
To eliminate these problems, we cannot avoid a new installation. We will organise the process as well as possible as follows:
We will migrate all Plesk web servers apart from the current ones, before that we will install and configure new servers. For the migration, we will route the current Plesk web server to a different IP address so that we already have correct IP addresses on the new servers before the migration - this will ensure the configuration and restoration of all sites. We will not be able to avoid interrupting the web display, and this should only last as long as the migration process continues. Subsequent error corrections still have to be taken into account.
The whole process will start at 10:00 am today and is expected to last until 4:00 pm. The time does not apply to each web server as a whole, but to all of them - as we are talking about over 13 web server nodes here.