I'm finally getting around to backing up projects from years ago. I like to keep all of the editing projects files (PPro & AE), RAW files and everything else I would need to jump back into the project years later if I need to. I realized that I don't know where DaVinci saves its projects to and if I can even access them? The only thing I can seem to find is "Export Project".
Yep, and when you export the project(s), make sure it includes the stills. If you want to dot the i's and cross the t's, you can also include thumbnails, which will make a bigger project. I also take a snapshot of the directory structure in case I have to redo the session elsewhere on a different computer, which will help preserve the media links in the database.
I would clean up the project removing and unused media and timelines, then export the project as a DRP manually and include LUTs, stills, etc. and use "Resolve Collect" to media manage the media. Reopen the project, connect to the newly media managed media, save and archive to spinning disks or LTO.
Painful, but I have found exporting to DRP much more reliable than manually copying folders from the database.