Mysql and new location for data with Errcode: 13 - Permission denied

For new instance data dir:

mysqld --initialize

mysqld: Can't create directory '/xxxx/mysql/' (Errcode: 13 - Permission denied)

add to file /etc/apparmor.d/ usr.sbin.mysqld new location

# Allow data dir access
  /var/lib/mysql/ r,
  /var/lib/mysql/** rwk,
 /xxxx/mysql/ r,  /xxxx/mysq/** rwk,

and reload apparmor

service apparmor reload

other way

apt install appamor-utils
aa-disable /usr/sbin/mysqld

Disabling /usr/sbin/mysqld.

mysqld --initialize

You can find password for root in /var/log/mysql/error.log

A temporary password is generated for root@localhost: xxxxxxxx