Status Quo: Ubuntu 14.04, php 5.5.9, using mod_apache, several dozen web sites that host archives of php apps/datasets to be maintained into the future. Some of these don’t work with newer versions of php (they use mysql() not mysqli().)
Goal: Ubuntu 18.04, php FCGI supporting multiple versions of php. All the existing sites on the server need to be supported.
I have done one “test” upgrade using do-release-upgrade to 16.04, and it mostly worked with a few tweaks. Previously I have upgraded servers by creating a new server from scratch and migrating sites manually or via Virtualmin migration functions. But the shear number of sites to deal with motivates me to find an easier way. Any advice appreciated.
Specific questions I have:
Are there issues I will run into by upgrading a server from 14.04 to 18.04?
I presume there’s no way to do that in one step? In other words, I will need to upgrade to 16.04 first, and then to 18.04?
Would be be better to set up FCGI on 14.04 before starting the upgrade process, or do it after I arrive at 18.04?
Also, while you’re at it, you might as well go on up to 20.04.
That is a question for the Ubuntu folks, but it is my understanding that there can’t be a greater jump, because the dependencies and conflicts would not be able to be designed to cross multiple versions. It’s already occasionally sketchy and needs some manual intervention or decision-making.
But, you may find it easier/faster/safer to backup your system fully (I like to have Virtualmin backups, plus a full system backup and a backup of /etc and the database dirs in /var…it’s overkill, but guarantees I can always get what I need if something goes weird on restore) and restore the Virtualmin backups onto a newly installed Ubuntu 18.04 or 20.04 system. Virtualmin backup restores try to fix up some stuff that upgrading the OS underneath it would not do (but will still miss some things in such a big jump).
Doesn’t matter. Same changes have to happen regardless. But, if you’re going to backup and restore, as I suggested above, it is better to switch before, as there is still a quirk on restore where we don’t fix up that mod_php mess (but next version will fix it, hopefully).
Also, I recommend you use PHP-FPM, if you can. Multiple versions is not currently supported in PHP-FPM, but most deployments don’t need multiple versions, you just need one modern one. We will hopefully have multiple versions in PHP-FPM soon (I’m hoping in time for Virtualmin 7), but I always encourage folks to simplify rather than complexify…adding more PHP versions just makes it more likely something will break.
Not possible, unfortunately. Many of the sites are stuck on php 5.5.9, but obviously I don’t want to use an unsupported version anywhere I don’t have to.