Moving MariaDB/mysql to another drive

[Paul Groves]

Hi. I just upgraded my 18.04 mariadb server to 20.04 and I cannot move the mysql data to a new directory the way I always have done.

Ever since 14.04 I usually do this and it has always worked:
     sudo service mariadb stop
     sudo mv /var/lib/mysql/ /home/
     sudo ln -s /home/mysql/ /var/lib/mysql
     sudo service mariadb start

Now I get this:
paul at nas02:~$ sudo tail /var/log/syslog
Jul 19 13:07:42 nas02 systemd[1]: mariadb.service: Succeeded.
Jul 19 13:07:42 nas02 systemd[1]: Stopped MariaDB 10.3.34 database server.
Jul 19 13:09:59 nas02 systemd[1]: Starting MariaDB 10.3.34 database server...
Jul 19 13:09:59 nas02 mysqld[24144]: 2022-07-19 13:09:59 0 [Note] /usr/sbin/mysqld (mysqld 10.3.34-MariaDB-0ubuntu0.20.04.1) starting as process 24144 ...
Jul 19 13:09:59 nas02 mysqld[24144]: 2022-07-19 13:09:59 0 [Warning] Can't create test file /var/lib/mysql/nas02.lower-test
Jul 19 13:09:59 nas02 mysqld[24144]: #007/usr/sbin/mysqld: Can't change dir to '/var/lib/mysql/' (Errcode: 13 "Permission denied")
Jul 19 13:09:59 nas02 mysqld[24144]: 2022-07-19 13:09:59 0 [ERROR] Aborting
Jul 19 13:09:59 nas02 systemd[1]: mariadb.service: Main process exited, code=exited, status=1/FAILURE
Jul 19 13:09:59 nas02 systemd[1]: mariadb.service: Failed with result 'exit-code'.
Jul 19 13:09:59 nas02 systemd[1]: Failed to start MariaDB 10.3.34 database server.

Can anyone shed some light on why this stopped working between versions?
Is there a new procedure or something for 20.04?

Regards
Paul