--初始化MySQL数据库的数据文件失败
[root@localhost maria]# ./scripts/mysql_install_db --user=mysql --datadir=/maria_data/
Installing MariaDB/MySQL system tables in '/maria_data/' ...
2016-06-17 17:31:21 140423554045920 [Note] ./bin/mysqld (mysqld 10.1.14-MariaDB) starting as process 13621 ...

Installation of system tables failed! Examine the logs in
/maria_data/ for more information.

The problem could be conflicting information in an external
my.cnf files. You can ignore these by doing:

shell> ./bin/scripts/mysql_install_db --defaults-file=~/.my.cnf

You can also try to start the mysqld daemon with:

shell> ./bin/mysqld --skip-grant --general-log &

and use the command line tool ./bin/mysql
to connect to the mysql database and look at the grant tables:

shell> ./bin/mysql -u root mysql
mysql> show tables;

Try 'mysqld --help' if you have problems with paths. Using
--general-log gives you a log in /maria_data/ that may be helpful.

The latest information about mysql_install_db is available at
https://mariadb.com/kb/en/installing-system-tables-mysql_install_db
MariaDB is hosted on launchpad; You can find the latest source and
email lists at http://launchpad.net/maria

Please check all of the above before submitting a bug report
at http://mariadb.org/jira

报错原因：
与/etc/my.cnf相冲突

解决方法：
将/etc/my.cnf改名

[root@localhost maria]# mv /etc/my.cnf /etc/my.cnf_5.7

--再次初始化数据文件成功

[root@localhost maria]# ./scripts/mysql_install_db --user=mysql --datadir=/maria_data/
.....
2016-06-17 17:37:16 139707541080032 [Note] InnoDB: Highest supported file format is Barracuda.
2016-06-17 17:37:16 139707541080032 [Note] InnoDB: 128 rollback segment(s) are active.
2016-06-17 17:37:16 139707541080032 [Note] InnoDB: Waiting for purge to start
2016-06-17 17:37:16 139707541080032 [Note] InnoDB: Percona XtraDB (http://www.percona.com) 5.6.29-76.2 started; log sequence number 1616819
2016-06-17 17:37:16 139706685712128 [Note] InnoDB: Dumping buffer pool(s) not yet started
OK

To start mysqld at boot time you have to copy
support-files/mysql.server to the right place for your system

PLEASE REMEMBER TO SET A PASSWORD FOR THE MariaDB root USER !
To do so, start the server, then issue the following commands:

'./bin/mysqladmin' -u root password 'new-password'
'./bin/mysqladmin' -u root -h localhost.localdomain password 'new-password'

Alternatively you can run:
'./bin/mysql_secure_installation'

which will also give you the option of removing the test
databases and anonymous user created by default. This is
strongly recommended for production servers.

See the MariaDB Knowledgebase at http://mariadb.com/kb or the
MySQL manual for more instructions.

You can start the MariaDB daemon with:
cd '.' ; ./bin/mysqld_safe --datadir='/maria_data/'

You can test the MariaDB daemon with mysql-test-run.pl
cd './mysql-test' ; perl mysql-test-run.pl

Please report any problems at http://mariadb.org/jira

The latest information about MariaDB is available at http://mariadb.org/.
You can find additional information about the MySQL part at:
http://dev.mysql.com
Support MariaDB development by buying support/new features from MariaDB
Corporation Ab. You can contact us about this at sales@mariadb.com.
Alternatively consider joining our community based development effort:
http://mariadb.com/kb/en/contributing-to-the-mariadb-project/