After deploying Rocky, I was surprised to find no volume service. Why is that?
I found the installation instructions https://docs.openstack.org/cinder/rocky/install/index.html (https://docs.openstack.org/cinder/roc...)
But I failed at the first step:

$ mysql -u root -p
-bash: mysql: command not found

i installed mysql, and then failed at the second step:

MariaDB [(none)]> CREATE DATABASE cinder;
ERROR 1006 (HY000): Can't create database 'cinder' (errno: 13 "Permission denied")

What am I doing wrong here? Thanks in advance.

MariaDB [(none)]> status
--------------
mysql  Ver 15.1 Distrib 10.1.20-MariaDB, for Linux (x86_64) using  EditLine wrapper

Connection id:          24178
Current database:
Current user:           root@localhost
SSL:                    Not in use
Current pager:          stdout
Using outfile:          ''
Using delimiter:        ;
Server:                 MariaDB
Server version:         10.1.20-MariaDB MariaDB Server
Protocol version:       10
Connection:             Localhost via UNIX socket
Server characterset:    latin1
Db     characterset:    latin1
Client characterset:    utf8
Conn.  characterset:    utf8
UNIX socket:            /var/lib/mysql/mysql.sock
Uptime:                 4 days 14 hours 48 min 24 sec

Threads: 96  Questions: 14193012  Slow queries: 0  Opens: 399  Flush tables: 1  Open tables: 393  Queries per second avg: 35.580
--------------


MariaDB [(none)]> show grants for 'root'@'%';     
+--------------------------------------------------------------------------------------------------------------------------------+
| Grants for root@%                                                                                                              |
+--------------------------------------------------------------------------------------------------------------------------------+
| GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' IDENTIFIED BY PASSWORD '*2D740E91859FA2915B803D2C28098923676C63B9' WITH GRANT OPTION |
+--------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

After Bernd Bauch comment I followed the procedure to install mariadb but the service doesn't start. Here is the output:

[stack@controller ~]$ sudo systemctl enable mariadb.service
Created symlink from /etc/systemd/system/multi-user.target.wants/mariadb.service to /usr/lib/systemd/system/mariadb.service.
[stack@controller ~]$ sudo systemctl start mariadb.service
Job for mariadb.service failed because the control process exited with error code. See "systemctl status mariadb.service" and "journalctl -xe" for details.
[stack@controller ~]$ sudo systemctl status mariadb.service
● mariadb.service - MariaDB 10.1 database server
   Loaded: loaded (/usr/lib/systemd/system/mariadb.service; enabled; vendor preset: disabled)
   Active: failed (Result: exit-code) since Sun 2019-04-07 19:20:45 UTC; 28s ago
  Process: 863969 ExecStopPost=/usr/libexec/mysql-wait-stop (code=exited, status=0/SUCCESS)
  Process: 863843 ExecStart=/usr/libexec/mysqld --basedir=/usr $MYSQLD_OPTS $_WSREP_NEW_CLUSTER (code=exited, status=1/FAILURE)
  Process: 863807 ExecStartPre=/usr/libexec/mysql-prepare-db-dir %n (code=exited, status=0/SUCCESS)
  Process: 863783 ExecStartPre=/usr/libexec/mysql-check-socket (code=exited, status=0/SUCCESS)
 Main PID: 863843 (code=exited, status=1/FAILURE)
   Status: "MariaDB server is down"

Apr 07 19:20:44 controller.mycloud.mycompany.com systemd[1]: Starting MariaDB 10.1 database server...
Apr 07 19:20:44 controller.mycloud.mycompany.com mysql-check-socket[863783]: Socket file /var/lib/mysql/mysql.sock exists.
Apr 07 19:20:44 controller.mycloud.mycompany.com mysql-check-socket[863783]: No process is using /var/lib/mysql/mysql.sock, which means it is a garbage, so it will be removed automatically.
Apr 07 19:20:44 controller.mycloud.mycompany.com mysql-prepare-db-dir[863807]: Database MariaDB is probably initialized in /var/lib/mysql already, nothing is done.
Apr 07 19:20:44 controller.mycloud.mycompany.com mysql-prepare-db-dir[863807]: If this ...