Change datanase directory in Nextcloud snap

I'm using Ubuntu 20.04 64 bit on a raspberry pi 4 with a SD card as boot drive and one external hard drive.

There are a lot of tutorials about how to move the data directory of Nextcloud itself to an external drive which I followed without issue (had to grant access to removable media to the snap but that was it).

Unfortunately I can't find much info about how to change the location of the MySQL server's data directory (e.g. where ibdata1 is stored).

Changing this directory would be a great thing, since sd cards aren't well suited for all these write cycles… I can imagine that, once all my directories are synched with my server, most of the actual writing would happen to the database, not even the file storage itself.

Does anyone tried this before?

Thanks in advance Markus