I managed to have CIVICRM (5.15.2 on WP 5.0.7 on Ubuntu 18) running on MySQL (5.7.28) from an encrypted mount via ecryptfs. Currently only the mysql files are in the encrypted mount and it's running a few days now and all seems good. I would like to check whether there are experiences from similar setup and whether there would be issues to anticipate ? Thanks.
Linking to your other question which is similar but slightly different since it's about using encryption that's natively supported by mariadb: Civicrm on mariadb with data encryption.
For this question, I have used a similar tool
encfs once for a non-civi setup to put the mysql files on an encrypted partition and it worked fine but the problem I had was the same as in the other post, that it partly defeats the purpose if you have to store the keys/password unencrypted on the same server, or else you can't do unattended reboots. It's a trade-off.