Moving the MySQL 8.4 LTS database to external drive (MacOS)

[Steve Epstein]

I am trying to archive email into a MySQL database using MailSteward (mailsteward.com). Since the database is likely to be large, and the main hard drive on my Macintosh is small, I would like the database to reside on an external drive.

In the MySQL Preference Pane, I can stop the server, and in the Configuration tab, specify a new path for the data directory. But when I then apply this and try to start the server, it fails.

I'm wondering if this has something to do with permissions for the new folder. The new folder has me as the owner, instead of _mysql. I have tried to change the owner to _mysql (sudo chown _mysql data), and while I do not get an error, when I then check (ls -l), I am still the owner - it's as if chown didn't work.

Any assistance appreciated. I figure having my email archive in a well-known standard database is pretty good assurance for my being able to retrieve my email in the future.