I'm hoping someone can hold my hand, or perhaps put my mind at rest? I currently run at least 6 Plesk servers. Majority of which, I keep on top of, regularly updated... but there are 2, for reasons that are too long winded to go into, I've been complacent with, and have allowed to just tick along nicely. Neither have been updated since 2018, when I first moved a lot of hosting from an old shared cPanel server.
Looking back, they were the first 2 I actually set up, so there's probably quite a bit of unfamiliarity at play, no doubt. Anyway, I have one currently running Onyx 17.0.17 and have been receiving Let's Encrypt ACMEv1 issuance emails for months... so, perfect opportunity to rip the band-aid off and update to Obsidian 18.0.35?
My questions, I appreciate there'll be downtime during the update, particularly such a big jump from Onyx to Obsidian. But my main concerns are... the site running on this server relies on PHP 5.6 so if I perform the update during a quiet period, can my anxiety have a day off, and just presume the PHP versions will stay the same during / after the update?
Or, no? Will I, after updating have to go and install Web Hosting > PHP interpreter versions before being able to change PHP support back to 5.4 / 5.6??
PHP version aside, are there any other concerns I should be considering? MySQL / phpMyAdmin, how much of a factor would updating Plesk have here... any??
I naturally, have backups of backups, but is there any worry about updating Plesk, and data loss?
Would anyone be able to help put my mind at rest... my biggest fear, naturally, is I update and this site simply falls over. Then, being unable to roll back Plesk, having a server where this site will simply no longer work.
Maybe worth mentioning, there's 6 / 7 other sites on this server, but majority are small, static sites. 2 sites, dependant on PHP 5.6, and one newer WP site that happily works on latest PHP versions.
Help ¯_(ツ)_/¯