MariaDB can't start procd in v21.02.0-rc3. The following modifications must be made:
Scheme 1: vi /etc/config/mysqld
config mysqld 'general'
- option options='--syslog'
+ option options=''
option enabled '1'
Scheme 2: vi /etc/init.d/mysqld # goto line:136
- procd_ set_ param command "$MYSQLD" $options
+ procd_ set_ param command "$MYSQLD" #$options