1.centos7现状：
新系统无法再使用yum install mysql-server来安装mysql，因为已使用mariadb代替mysql。
2.安装mariadb：
[root@localhost ~]# yum -y install mariadb* Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile * base: mirrors.linode.com * extras: mirrors.linode.com * updates: mirrors.linode.com Resolving Dependencies --> Running transaction check ---> Package mariadb.x86_64 1:5.5.37-1.el7_0 will be installed ---> Package mariadb-bench.x86_64 1:5.5.37-1.el7_0 will be installed ---> Package mariadb-devel.x86_64 1:5.5.37-1.el7_0 will be installed ---> Package mariadb-embedded.x86_64 1:5.5.37-1.el7_0 will be installed ---> Package mariadb-embedded-devel.x86_64 1:5.5.37-1.el7_0 will be installed ---> Package mariadb-libs.x86_64 1:5.5.37-1.el7_0 will be installed ---> Package mariadb-server.x86_64 1:5.5.37-1.el7_0 will be installed --> Processing Dependency: perl-DBD-MySQL for package: 1:mariadb-server-5.5.37-1.el7_0.x86_64 ---> Package mariadb-test.x86_64 1:5.5.37-1.el7_0 will be installed --> Running transaction check ---> Package perl-DBD-MySQL.x86_64 0:4.023-5.el7 will be installed --> Finished Dependency Resolution Dependencies Resolved ========================================================================================================== Package Arch Version Repository Size ========================================================================================================== Installing: mariadb x86_64 1:5.5.37-1.el7_0 updates 8.9 M mariadb-bench x86_64 1:5.5.37-1.el7_0 updates 385 k mariadb-devel x86_64 1:5.5.37-1.el7_0 updates 744 k mariadb-embedded x86_64 1:5.5.37-1.el7_0 updates 3.6 M mariadb-embedded-devel x86_64 1:5.5.37-1.el7_0 updates 7.4 M mariadb-libs x86_64 1:5.5.37-1.el7_0 updates 752 k mariadb-server x86_64 1:5.5.37-1.el7_0 updates 11 M mariadb-test x86_64 1:5.5.37-1.el7_0 updates 7.9 M Installing for dependencies: perl-DBD-MySQL x86_64 4.023-5.el7 base 140 k Transaction Summary ========================================================================================================== Install 8 Packages (+1 Dependent package) Total download size: 40 M Installed size: 279 M Downloading packages: (1/9): mariadb-bench-5.5.37-1.el7_0.x86_64.rpm | 385 kB 00:00:00 (2/9): mariadb-devel-5.5.37-1.el7_0.x86_64.rpm | 744 kB 00:00:00 (3/9): mariadb-embedded-5.5.37-1.el7_0.x86_64.rpm | 3.6 MB 00:00:00 (4/9): mariadb-5.5.37-1.el7_0.x86_64.rpm | 8.9 MB 00:00:00 (5/9): mariadb-libs-5.5.37-1.el7_0.x86_64.rpm | 752 kB 00:00:00 (6/9): mariadb-server-5.5.37-1.el7_0.x86_64.rpm | 11 MB 00:00:00 (7/9): mariadb-embedded-devel-5.5.37-1.el7_0.x86_64.rpm | 7.4 MB 00:00:00 (8/9): mariadb-test-5.5.37-1.el7_0.x86_64.rpm | 7.9 MB 00:00:00 (9/9): perl-DBD-MySQL-4.023-5.el7.x86_64.rpm | 140 kB 00:00:00 ---------------------------------------------------------------------------------------------------------- Total 36 MB/s | 40 MB 00:00:01 Running transaction check Running transaction test Transaction test succeeded Running transaction Installing : 1:mariadb-libs-5.5.37-1.el7_0.x86_64 1/9 Installing : 1:mariadb-5.5.37-1.el7_0.x86_64 2/9 Installing : perl-DBD-MySQL-4.023-5.el7.x86_64 3/9 Installing : 1:mariadb-server-5.5.37-1.el7_0.x86_64 4/9 Installing : 1:mariadb-devel-5.5.37-1.el7_0.x86_64 5/9 Installing : 1:mariadb-embedded-5.5.37-1.el7_0.x86_64 6/9 Installing : 1:mariadb-embedded-devel-5.5.37-1.el7_0.x86_64 7/9 Installing : 1:mariadb-test-5.5.37-1.el7_0.x86_64 8/9 Installing : 1:mariadb-bench-5.5.37-1.el7_0.x86_64 9/9 Verifying : 1:mariadb-test-5.5.37-1.el7_0.x86_64 1/9 Verifying : 1:mariadb-embedded-devel-5.5.37-1.el7_0.x86_64 2/9 Verifying : 1:mariadb-embedded-5.5.37-1.el7_0.x86_64 3/9 Verifying : 1:mariadb-libs-5.5.37-1.el7_0.x86_64 4/9 Verifying : 1:mariadb-bench-5.5.37-1.el7_0.x86_64 5/9 Verifying : 1:mariadb-5.5.37-1.el7_0.x86_64 6/9 Verifying : 1:mariadb-server-5.5.37-1.el7_0.x86_64 7/9 Verifying : perl-DBD-MySQL-4.023-5.el7.x86_64 8/9 Verifying : 1:mariadb-devel-5.5.37-1.el7_0.x86_64 9/9 Installed: mariadb.x86_64 1:5.5.37-1.el7_0 mariadb-bench.x86_64 1:5.5.37-1.el7_0 mariadb-devel.x86_64 1:5.5.37-1.el7_0 mariadb-embedded.x86_64 1:5.5.37-1.el7_0 mariadb-embedded-devel.x86_64 1:5.5.37-1.el7_0 mariadb-libs.x86_64 1:5.5.37-1.el7_0 mariadb-server.x86_64 1:5.5.37-1.el7_0 mariadb-test.x86_64 1:5.5.37-1.el7_0 Dependency Installed: perl-DBD-MySQL.x86_64 0:4.023-5.el7 Complete! [root@localhost ~]# systemctl start mariadb.service [root@localhost ~]# systemctl enable mariadb.service ln -s '/usr/lib/systemd/system/mariadb.service' '/etc/systemd/system/multi-user.target.wants/mariadb.servi ce' [root@localhost ~]# mysql Welcome to the MariaDB monitor. Commands end with ; or g. Your MariaDB connection id is 2 Server version: 5.5.37-MariaDB MariaDB Server Copyright (c) 2000, 2014, Oracle, Monty Program Ab and others. Type 'help;' or 'h' for help. Type 'c' to clear the current input statement. MariaDB [(none)]> logout -> exit -> -> ; ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MariaD B server version for the right syntax to use near 'logout exit' at line 1 MariaDB [(none)]> exit Bye [root@localhost ~]# systemctl enable mariadb.service [root@localhost ~]# mysql Welcome to the MariaDB monitor. Commands end with ; or g. Your MariaDB connection id is 3 Server version: 5.5.37-MariaDB MariaDB Server Copyright (c) 2000, 2014, Oracle, Monty Program 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 | | test | +--------------------+ 4 rows in set (0.00 sec) MariaDB [(none)]> use test Database changed MariaDB [test]> show tables; Empty set (0.00 sec) MariaDB [test]> exit Bye [root@localhost ~]# 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. ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES) 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] y 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] y ... 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] y ... 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] y - 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] y ... 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@localhost ~]# mysql -uroot -p Enter password: Welcome to the MariaDB monitor. Commands end with ; or g. Your MariaDB connection id is 15 Server version: 5.5.37-MariaDB MariaDB Server Copyright (c) 2000, 2014, Oracle, Monty Program 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 | | zbphp.com | +--------------------+ 4 rows in set (0.00 sec) MariaDB [(none)]>