Cannot start MySQL service on linux RHEL when pointing datadir to mounted ecryptfs folder
Make sure the MySQL server owner is MySQL:MySQL using chown -R mysql:mysql /mysql and the permission level is 755 for everything except my.cnf 644. chmod 644 my.cnf then execute the following commands after changing the information inside my.cnf to the correct one.

cd /mysql/bin
./mysqld --defaults-file=/mysql/my.cnf --user=mysql &amp;


Edit to answer the comment below
To shutdown MySQL safely without killing the SID (or PID) you can use one of the following commands:

/usr/local/mysql/bin/mysqladmin -u root -p shutdown 


or

sudo mysqld stop


note: in-case you can more than SID running you need to specify the port for it.