Here is a link to a past discussion from some months about updating from 16 to 17:
Before Upgrading To Resolve 17viewtopic.php?f=21&t=1250451) launch Resolve and backup Project Databases using the backup utility
2) export Keyboard Shortcuts
3) export all personal PowerGrades as DPX stills + DRX grades to specific folders (and LUTs if you must)
4) jot down Project Config and User settings (in case those don't make it over)
5) jot down Data Burn-In settings
6) jot down Custom Export settings on Deliver page
7) jot down custom Power Window presets
9) backup 3rd-party/custom LUTs
10) export all custom PowerGrades (with labeled stills) to a folder
11) de-install any 3rd-party OFX plug-ins (BorisFX, Sapphire, Dehancer, Beauty Box, Filmlook, Neat Video, etc.), and have the serial numbers ready when you install the new Resolve.
12) important: backup all current in-progress sessions as DRP files "just in case."
The TL;dr version: back up your current project session files, back up your project database, back up your boot drive if possible (so you could revert back to the old setup), and use caution. In general, the process works very well and is fairly seamless... most of the time.