file with admin settings

Yep, adding to what Dave said (and thanks for the shout-out), I'll point out that the CAR feature was changed in CF11 so that it IS available even in Standard, but that won't help you on CF9. (I did a post about that, FWIW.)

As for that migration wizard (which runs on first execution of the Admin, looking for any previous version on the same machine, to offer to import its admin settings), like Dave said, I'm not sure CF2018 will offer to migrate CF9 settings, but it may. I will note that if you DO have CF9 on the same machine as CF2018, and you DID already run the CF2018 admin for the first time, you CAN force it to run again. I have a post about that also, and you will see that I even show how to use it if the older CF version was on another machine. Finally, I also show how it's an xml file that controls the migration, which names the version to migrate, and you could try forcing it to be CF9, though like Dave I have not tried it.

But if you want to skip trying to do the migration (and like Dave, I would warn strongly against just doing a copy of the xml files that hold the admin settings), there is one more thing you can do. Of course, most just resort to opening the CF Admin of each version in two browsers and go back and forth comparing them. But you can do it even faster than that: just go to the "settings summary" page in the CF admin (in the first "Settings" section).

That one page shows nearly all the CF admin settings, and you can easily eyeball a comparison of that--but even better, just copy the text (in that page) to your clipboard and paste it into any compare tool or editor that can do comparisons. (I favor BeyondCompare for this, which works on Win/Mac/Linux and has a very generous trial period.) Such a tool can help easily spot differences in those settings.

Finally, FWIW, this is all stuff that I plan to cover in an upcoming session of the online ColdFusion Meetup (coldfusionmeetup.com), possibly as early as July 2. But I hope the info above may help you suitably before then.

These settings are stored in a bunch of XML files. However, I don't think those files don't share the exact same structure across all those versions. CF does provide a built-in tool that lets you export and import settings. You can create a "car" file that contains those settings in CF 9, then import them in CF 2018, and they should generally work as long as you don't export and import version-specific settings like your JVM configuration.

Unfortunately, this tool is only available in Trial and Enterprise versions of CF. But you can "downgrade" your Standard license to Trial, I think, then run the tool. I've never had to do this, myself, but I'm pretty sure @carehart has instructions on his blog somewhere:

https://www.carehart.org/blog/

Also, if you're installing CF 2018 over CF 9, it may automatically pick up those settings with the migration wizard. Honestly, I haven't gone from CF 9 to CF 2018 - that's a big jump - so it may not be able to pick those up. But you can probably set up a test environment and see before you do this in a production environment. You can actually run the migration wizard after the fact, apparently:

https://www.carehart.org/blog/client/index.cfm/2014/11/11/import_cfadmin_settings_anytime_using_import_wizard

Dave Watts, Eidolon LLC