Hello, Is it possible to upgrade Debian 9 multiserver setup to Debian 10 safely? Update extremely required to use PHP 7.3. Can anyone please advise?
Do you mean - you have diferent versions in multiserver setup And all your servers works fine - can connect to master server?
PHP 7.3 is possible on Debian Stretch with ISPConfig: https://www.howtoforge.com/tutorial...fig-3-from-debian-packages-on-debian-8-and-9/ Also upgrading a multiserver ISPConfig Debian 9 -> Debian 10 should work, if you take care to do the upgrade correctly. Safely would need qualification. I say it can be done, but it is possible to create a big mess. Plan beforehand, experiment with a test setup, take image backup before starting upgrade and prepare for some downtime. If you can create a separate new setup with ISPConfig and Debian 10, you can use ISPConfig Migration Toolkit to copy over all the data from old setup to new.