不多说，直接上干货！
直接yum install mysql的话会报错，原因在于yum安装库里没有直接可以用的安装包，此时需要用到MariaDB了，MariaDB是MySQL社区开发的分支，也是一个增强型的替代品。
安装ossec时需要使用到mysql-server，直接安装报错：
[root@ossec-server ~]# yum install mysql-server Loaded plugins: fastestmirror, langpacks Loading mirror speeds from cached hostfile No package mysql-server available. Error: Nothing to do
原因是yum安装库里没有直接可以用的安装包，这时候就需要用到MariaDB了，MariaDB是MySQL社区开发的分支，也是一个增强型的替代品。
1.安装mariadb
yum -y install MariaDB-server MariaDB MariaDB-devel systemctl start mariadb systemctl enable mariadb mysql_secure_installation firewall-cmd --permanent --add-service mysql systemctl restart firewalld.service iptables -L -n|grep 3306
[root@ossec-server Desktop]# yum -y install mariadb-server mariadb mariadb-devel
Loaded plugins: fastestmirror, langpacks
Loading mirror speeds from cached hostfile
Package 1:mariadb-server-5.5.47-1.el7_2.x86_64 already installed and latest version
Package 1:mariadb-5.5.47-1.el7_2.x86_64 already installed and latest version
Package 1:mariadb-devel-5.5.47-1.el7_2.x86_64 already installed and latest version
Nothing to do
[root@ossec-server Desktop]# systemctl start mariadb
[root@ossec-server Desktop]# systemctl start mariadb
[root@ossec-server Desktop]# systemctl enable mariadb
[root@ossec-server Desktop]# mysql_secure_installation
/usr/bin/mysql_secure_installation: line 379: find_mysql_client: command not found
NOTE: RUNNING ALL PARTS OF THIS SCRIPT IS RECOMMENDED FOR ALL MariaDB
SERVERS IN PRODUCTION USE! PLEASE READ EACH STEP CAREFULLY!
In order to log into MariaDB to secure it, we'll need the current
password for the root user. If you've just installed MariaDB, and
you haven't set the root password yet, the password will be blank,
so you should just press enter here.
Enter current password for root (enter for none):
OK, successfully used password, moving on...
Setting the root password ensures that nobody can log into the MariaDB
root user without the proper authorisation.
Set root password? [Y/n]
New password:
Re-enter new password:
Password updated successfully!
Reloading privilege tables..
... Success!
By default, a MariaDB installation has an anonymous user, allowing anyone
to log into MariaDB without having to have a user account created for
them. This is intended only for testing, and to make the installation
go a bit smoother. You should remove them before moving into a
production environment.
Remove anonymous users? [Y/n]
... Success!
Normally, root should only be allowed to connect from 'localhost'. This
ensures that someone cannot guess at the root password from the network.
Disallow root login remotely? [Y/n]
... Success!
By default, MariaDB comes with a database named 'test' that anyone can
access. This is also intended only for testing, and should be removed
before moving into a production environment.
Remove test database and access to it? [Y/n]
- Dropping test database...
... Success!
- Removing privileges on test database...
... Success!
Reloading the privilege tables will ensure that all changes made so far
will take effect immediately.
Reload privilege tables now? [Y/n]
... Success!
Cleaning up...
All done! If you've completed all of the above steps, your MariaDB
installation should now be secure.
Thanks for using MariaDB!
[root@ossec-server Desktop]# firewall-cmd --permanent --add-service mysql
success
[root@ossec-server Desktop]# systemctl restart firewalld.service
[root@ossec-server Desktop]# iptables -L -n|grep 3306
ACCEPT tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpt:3306 ctstate NEW
[root@ossec-server Desktop]#
2.登录数据库查看是否设置成功
mysql -uroot -p show databases;
[root@ossec-server Desktop]# mysql -uroot -p
Enter password:
Welcome to the MariaDB monitor. Commands end with ; or g.
Your MariaDB connection id is 13
Server version: 5.5.47-MariaDB MariaDB Server
Copyright (c) 2000, 2015, Oracle, MariaDB Corporation Ab and others.
Type 'help;' or 'h' for help. Type 'c' to clear the current input statement.
MariaDB [(none)]> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
+--------------------+
3 rows in set (0.00 sec)
MariaDB [(none)]>
mariadb相关命令：
systemctl start mariadb #启动MariaDB systemctl stop mariadb #停止MariaDB systemctl restart mariadb #重启MariaDB systemctl enable mariadb #设置开机启动
同时，大家可以关注我的个人博客：
http://www.cnblogs.com/zlslch/ 和 http://www.cnblogs.com/lchzls/ http://www.cnblogs.com/sunnyDream/
详情请见：http://www.cnblogs.com/zlslch/p/7473861.html
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