Upgrading FM Sever from v. 20.3.1.31 to FM Server v. 21.1.1 checklist

[djc728]

First off I want to say that I haven't done a FileMaker Server upgrade since probably version 17 so it's been awhile.  I'm looking for a best practices checklist if you will.  I know I can upgrade to the latest and greatest via the admin console but before I click that nice button that says "Upgrade FileMaker Server" I want to be sure I have my ducks in a row.  

( 1 ) I have already downloaded the lastest version ( 21.1.1.1 ) of FileMaker Server to my FileMaker Server machine.

( 2 ) I'm going to run a full backup on all the open files.

( 3 ) Our plugins are compatible as we only use MBS and BaseElements.

Once I click the "Upgrade FileMaker Server" will it handle the rest at this point or do I need shut off any FileMaker services or close the databases PRIOR to clicking his button etc.  Do I need to backup my Backup Schedules and Server Side Schedules prior or will they be preserved after the upgrade.

Any tips or gotchas to look out for would greatly appreciated.

Thanks all.

Dom