[[email protected] ~]# rpm -qa | grep mariadb                     // 列出mariadb相關已安裝包

mariadb-libs-5.5.40-1.el7_0.x86_64                      // 本例中找到的相關RPM包

[[email protected] ~]# rpm -e --nodeps mariadb-libs-5.5.40-1.el7_0.x86_64      // 解除安裝上面找到的所有相關RPM包

[[email protected] ~]# rpm -qa | grep mariadb                         // 在解除安裝完以後再次用此命令來檢視

[[email protected]~]#                                         // 未查詢到，表明mariadb已經解除安裝成功！！

[[email protected] ~]# yum install -y perl-Module-Install.noarch

[[email protected] ~]# yum -y install perl

[[email protected] ~]# yum -y install libaio                                                                   // CentOS7最小版本安裝MySQL找不到Perl的依賴包的解決辦法，或MySQL通過rpm包方式安裝時，不會執行mysql_install_db從而生成/root/.mysql_secret等，是缺少上面這3個依賴，所以我們先裝下(如果已有會提示你無需安裝)，以免安裝過程出錯要解除安裝重灌更麻煩。

[[email protected] ~]# cd /data/AtlassianResource                                                // 進入AtlassianResource目錄下

[[email protected] AtlassianResource]# rpm -ivh MySQL-server-5.6.26-1.el7.x86_64.rpm             // 執行安裝MySQL-server，安裝過程有如下提示（若Centos最小化安裝，可能還需要依賴包：yum -y install libaio、yum -y install perl和yum -y install perl-Module-Install.noarch）：

Preparing...                ########################################### [100%]

   1:MySQL-server           ########################################### [100%]

warning: user mysql does not exist - using root

warning: group mysql does not exist - using root

2015-01-20 13:10:42 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).

2015-01-20 13:10:42 5645 [Note] InnoDB: Using atomics to ref count buffer pool pages

2015-01-20 13:10:42 5645 [Note] InnoDB: The InnoDB memory heap is disabled

2015-01-20 13:10:42 5645 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins

2015-01-20 13:10:42 5645 [Note] InnoDB: Memory barrier is not used

2015-01-20 13:10:42 5645 [Note] InnoDB: Compressed tables use zlib 1.2.3

2015-01-20 13:10:42 5645 [Note] InnoDB: Using Linux native AIO

2015-01-20 13:10:42 5645 [Note] InnoDB: Not using CPU crc32 instructions

2015-01-20 13:10:42 5645 [Note] InnoDB: Initializing buffer pool, size = 128.0M

2015-01-20 13:10:42 5645 [Note] InnoDB: Completed initialization of buffer pool

2015-01-20 13:10:42 5645 [Note] InnoDB: The first specified data file ./ibdata1 did not exist: a new database to be created!

2015-01-20 13:10:42 5645 [Note] InnoDB: Setting file ./ibdata1 size to 12 MB

2015-01-20 13:10:42 5645 [Note] InnoDB: Database physically writes the file full: wait...

2015-01-20 13:10:42 5645 [Note] InnoDB: Setting log file ./ib_logfile101 size to 48 MB

2015-01-20 13:10:42 5645 [Note] InnoDB: Setting log file ./ib_logfile1 size to 48 MB

2015-01-20 13:10:43 5645 [Note] InnoDB: Renaming log file ./ib_logfile101 to ./ib_logfile0

2015-01-20 13:10:43 5645 [Warning] InnoDB: New log files created, LSN=45781

2015-01-20 13:10:43 5645 [Note] InnoDB: Doublewrite buffer not found: creating new

2015-01-20 13:10:43 5645 [Note] InnoDB: Doublewrite buffer created

2015-01-20 13:10:43 5645 [Note] InnoDB: 128 rollback segment(s) are active.

2015-01-20 13:10:43 5645 [Warning] InnoDB: Creating foreign key constraint system tables.

2015-01-20 13:10:43 5645 [Note] InnoDB: Foreign key constraint system tables created

2015-01-20 13:10:43 5645 [Note] InnoDB: Creating tablespace and datafile system tables.

2015-01-20 13:10:43 5645 [Note] InnoDB: Tablespace and datafile system tables created.

2015-01-20 13:10:43 5645 [Note] InnoDB: Waiting for purge to start

2015-01-20 13:10:43 5645 [Note] InnoDB: 5.6.22 started; log sequence number 0

A random root password has been set. You will find it in '/root/.mysql_secret'.

2015-01-20 13:10:44 5645 [Note] Binlog end

2015-01-20 13:10:44 5645 [Note] InnoDB: FTS optimize thread exiting.

2015-01-20 13:10:44 5645 [Note] InnoDB: Starting shutdown...

2015-01-20 13:10:45 5645 [Note] InnoDB: Shutdown completed; log sequence number 1625977

2015-01-20 13:10:45 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).

2015-01-20 13:10:45 5667 [Note] InnoDB: Using atomics to ref count buffer pool pages

2015-01-20 13:10:45 5667 [Note] InnoDB: The InnoDB memory heap is disabled

2015-01-20 13:10:45 5667 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins

2015-01-20 13:10:45 5667 [Note] InnoDB: Memory barrier is not used

2015-01-20 13:10:45 5667 [Note] InnoDB: Compressed tables use zlib 1.2.3

2015-01-20 13:10:45 5667 [Note] InnoDB: Using Linux native AIO

2015-01-20 13:10:45 5667 [Note] InnoDB: Not using CPU crc32 instructions

2015-01-20 13:10:45 5667 [Note] InnoDB: Initializing buffer pool, size = 128.0M

2015-01-20 13:10:45 5667 [Note] InnoDB: Completed initialization of buffer pool

2015-01-20 13:10:45 5667 [Note] InnoDB: Highest supported file format is Barracuda.

2015-01-20 13:10:45 5667 [Note] InnoDB: 128 rollback segment(s) are active.

2015-01-20 13:10:45 5667 [Note] InnoDB: Waiting for purge to start

2015-01-20 13:10:45 5667 [Note] InnoDB: 5.6.22 started; log sequence number 1625977

2015-01-20 13:10:45 5667 [Note] Binlog end

2015-01-20 13:10:45 5667 [Note] InnoDB: FTS optimize thread exiting.

2015-01-20 13:10:45 5667 [Note] InnoDB: Starting shutdown...

2015-01-20 13:10:47 5667 [Note] InnoDB: Shutdown completed; log sequence number 1625987

A RANDOM PASSWORD HAS BEEN SET FOR THE MySQL root USER !

You will find that password in '/root/.mysql_secret'.                                      // 此句提示你預設mysql的root使用者隨機密碼存放於“/root/.mysql_secret”中

You must change that password on your first connect,

no other statement but 'SET PASSWORD' will be accepted.

See the manual for the semantics of the 'password expired' flag.

Also, the account for the anonymous user has been removed.

In addition, you can run:

  /usr/bin/mysql_secure_installation

which will also give you the option of removing the test database.

This is strongly recommended for production servers.

See the manual for more instructions.

Please report any problems at http://bugs.mysql.com/

The latest information about MySQL is available on the web at

  http://www.mysql.com

Support MySQL by buying support/licenses at http://shop.mysql.com

New default config file was created as /usr/my.cnf and                                     // 此句提示你mysql的配置檔案位置“/usr/my.cnf”

will be used by default by the server when you start it.

You may edit this file to change server settings

[[email protected] AtlassianResource]# rpm -ivh MySQL-client-5.6.26-1.el7.x86_64.rpm             // 執行安裝MySQL-client

Preparing...                ########################################### [100%]

   1:MySQL-client           ########################################### [100%]

[[email protected] AtlassianResource]#                                                           // 安裝成功

/usr/bin

客戶端程式和可執行檔案、指令碼

/usr/sbin

服務端程式

/var/lib/mysql

日誌檔案、資料庫檔案  ［重點要知道這個］

/usr/share/info

資訊檔案

/usr/share/man

聯機幫助文件目錄

/usr/include/mysql

C標頭檔案目錄

/usr/lib/mysql

lib庫檔案目錄

/usr/share/mysql

其他支援檔案，包括錯誤資訊，字符集檔案，示例配置檔案，SQL資料庫的安裝

/usr/share/sql-bench

基準程式

[[email protected] ~]# service mysql start                                                // 啟動命令

[[email protected] ~]# service mysql stop                                                 // 停止命令

[[email protected] ~]# service mysql start                                                // 啟動MySQL

[[email protected] ~]# cat /root/.mysql_secret                                            // 檢視MySQL root使用者的預設隨機密碼

# The random password set for the root user at Tue Jan 20 13:10:43 2015 (local time): F76Wy1A4G9ZuLcaG

[[email protected] ~]# mysqladmin -u root -pF76Wy1A4G9ZuLcaG password F76Wy1A4G9ZuLcaH    // 改密命令格式：mysqladmin -u 使用者名稱 -p原密碼 password 新密碼(注意-p後面不要有空格)，本例將原密碼末尾字母G改成H。

Warning: Using a password on the command line interface can be insecure.            // 看到此句表明密碼已經修改成功

[[email protected] ~]# mysql -u root -p                                                   // 用新密碼登入看看

Enter password:

Welcome to the MySQL monitor.  Commands end with ; or \g.

Your MySQL connection id is 16

Server version: 5.6.22 MySQL Community Server (GPL)

Copyright (c) 2000, 2014, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its

affiliates. Other names may be trademarks of their respective

owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql>                                                                              // 新密碼登入成功

mysql> exit                                                                         // 退出MySQL

Bye

[[email protected] ~]#

[[email protected] ~]# rm -rf /root/.mysql_secret                                         // 這個檔案可以刪除了，我們已經改密了，它已經沒有存在的價值了。（新密碼記得記錄儲存好噢噢噢！）

[[email protected] ~]# service mysql stop                                                 // 先停止MySQL服務

[[email protected] ~]# vi /usr/my.cnf                                                     // 編輯my.cnf配置檔案，下文中標“[###]”的行為新增或修改過的配置

# For advice on how to change settings please see

# http://dev.mysql.com/doc/refman/5.6/en/server-configuration-defaults.html

[mysql]                                                                             // [###]

default-character-set=utf8                                                          // [###]

[mysqld]

# Remove leading # and set to the amount of RAM for the most important data

# cache in MySQL. Start at 70% of total RAM for dedicated server, else 10%.

# innodb_buffer_pool_size = 128M

# Remove leading # to turn on a very important data integrity option: logging

# changes to the binary log between backups.

# log_bin

# These are commonly set, remove the # and set as required.

# basedir = .....

# datadir = .....

# port = .....

# server_id = .....

# socket = .....

# Remove leading # to set options mainly useful for reporting servers.

# The server defaults are faster for transactions and fast SELECTs.

# Adjust sizes as needed, experiment to find the optimal values.

# join_buffer_size = 128M

# sort_buffer_size = 2M

# read_rnd_buffer_size = 2M

sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES

transaction-isolation = READ-COMMITTED                                              // [###]

max_allowed_packet=128M                                                             // [###]

innodb_log_file_size=512M                                                           // [###]

innodb_buffer_pool_size=512M                                                        // [###]

innodb_file_per_table=1                                                             // [###]

collation-server=utf8_bin                                                           // [###]

character-set-server=utf8                                                           // [###]

default-storage-engine=INNODB                                                       // [###]

performance_schema_max_table_instances=400                                          // [###] 此行和下面兩行配置，新增後，若MySQL無法啟動，則請刪除；若可正常啟動，則最好新增上。

table_definition_cache=400                                                          // [###]

table_open_cache=256                                                                // [###]

[[email protected] mysql]# cd /var/lib/mysql/                                             // 進入這個目錄，ls下我們可看到兩個檔案ib_logfile0和ib_logfile1

[[email protected] mysql]# rm -rf ib_logfile*                                             // 刪除這兩個檔案

[[email protected] mysql]# service mysql start                                            // 重新啟動MySQL服務，後面看配置是否生效

[[email protected] mysql]# mysql -u root -p                                               // 登入MySQL

Enter password:

Welcome to the MySQL monitor.  Commands end with ; or \g.

Your MySQL connection id is 18848

Server version: 5.6.22 MySQL Community Server (GPL)

Copyright (c) 2000, 2014, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its

affiliates. Other names may be trademarks of their respective

owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> show VARIABLES like '%max_allowed_packet%';                                  // 檢視最大包限制大小

+--------------------------+------------+

| Variable_name            | Value      |

+--------------------------+------------+

| max_allowed_packet       | 134217728  |

| slave_max_allowed_packet | 1073741824 |

+--------------------------+------------+

2 rows in set (0.00 sec)

mysql> SHOW VARIABLES LIKE 'character%';                                            // 檢視字符集變數

+--------------------------+----------------------------+

| Variable_name            | Value                      |

+--------------------------+----------------------------+

| character_set_client     | utf8                       |

| character_set_connection | utf8                       |

| character_set_database   | utf8                       |

| character_set_filesystem | binary                     |

| character_set_results    | utf8                       |

| character_set_server     | utf8                       |

| character_set_system     | utf8                       |

| character_sets_dir       | /usr/share/mysql/charsets/ |

+--------------------------+----------------------------+

8 rows in set (0.00 sec)

mysql>                                                                              // 看到上面這些配置，表示我們前面修改的配置已經生效了。