安裝Mysql:

0、下載：(我的系統是 CentOS 64位，選擇下載64位Mysql5.6)

wget https://dev.mysql.com/get/Downloads/MySQL-5.6/mysql-5.6.42-linux-glibc2.12-x86_64.tar.gz

這裡我沒有采用先離線下載後上傳到伺服器的方式，而是直接伺服器線上下載，不過速度還是很快的！（之前試圖離線下載，沒想到速度很慢，幾次下載都中斷了）

1、解除安裝老版本mysql:   

這步主要是防止之前已經安裝了，會影響現在安裝

      查詢並刪除mysql有關的檔案

find / -name mysql
rm -rf     //上邊查詢到的路徑，多個路徑用空格隔開
//或者下邊一條命令即可
find / -name mysql|xargs rm -rf
 

2、解壓mysql:

tar -zxvf mysql-5.6.42-linux-glibc2.12-x86_64.tar.gz -C /usr/local

為了方便，我們可以對加壓後查mysql資料夾重新命名

mv mysql-5.6.42-linux-glibc2.12-x86_64 mysql 

3、新增mysql使用者組和mysql使用者：

先檢查是否有mysql使用者組和mysql使用者：

groups mysql

如果沒有就新增：

groupadd mysql
useradd -r -g mysql mysql

新增成功。

4、進入mysql目錄更改許可權(修改當前目錄擁有者為mysql)：

cd mysql/
chown -R mysql:mysql ./

5、執行安裝指令碼:

./scripts/mysql_install_db --user=mysql

此時會報以下錯誤：

[[email protected] mysql]# ./scripts/mysql_install_db --user=mysql
FATAL ERROR: please install the following Perl modules before executing ./scripts/mysql_install_db:
Data::Dumper

解決方法 ：安裝autoconf庫

  命令：yum -y install autoconf   //此包安裝時會安裝Data:Dumper模組

安裝完autoconf庫之後，再執行  ./scripts/mysql_install_db --user=mysql  ，又可能出現下面的錯誤！

[[email protected] mysql]# ./scripts/mysql_install_db --user=mysql
Installing MySQL system tables..../bin/mysqld: error while loading shared libraries: libaio.so.1: cannot open shared object file: No such file or directory

 出現該問題首先檢查該連結庫檔案有沒有安裝，使用命令進行核查：

rpm -qa|grep libaio   

執行該命令後發現系統中無該連結庫檔案

那麼請使用以下命令安裝: 

yum -y install libaio-devel.x86_64

安裝成功後，繼續執行資料庫的初始化命令，提示成功。

[[email protected] mysql]# ./scripts/mysql_install_db --user=mysql
Installing MySQL system tables...2018-11-18 00:13:52 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
2018-11-18 00:13:52 0 [Note] Ignoring --secure-file-priv value as server is running with --bootstrap.
2018-11-18 00:13:52 0 [Note] ./bin/mysqld (mysqld 5.6.42) starting as process 18662 ...
2018-11-18 00:13:52 18662 [Note] InnoDB: Using atomics to ref count buffer pool pages
2018-11-18 00:13:52 18662 [Note] InnoDB: The InnoDB memory heap is disabled
2018-11-18 00:13:52 18662 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
2018-11-18 00:13:52 18662 [Note] InnoDB: Memory barrier is not used
2018-11-18 00:13:52 18662 [Note] InnoDB: Compressed tables use zlib 1.2.11
2018-11-18 00:13:52 18662 [Note] InnoDB: Using Linux native AIO
2018-11-18 00:13:52 18662 [Note] InnoDB: Using CPU crc32 instructions
2018-11-18 00:13:52 18662 [Note] InnoDB: Initializing buffer pool, size = 128.0M
2018-11-18 00:13:52 18662 [Note] InnoDB: Completed initialization of buffer pool
2018-11-18 00:13:52 18662 [Note] InnoDB: The first specified data file ./ibdata1 did not exist: a new database to be created!
2018-11-18 00:13:52 18662 [Note] InnoDB: Setting file ./ibdata1 size to 12 MB
2018-11-18 00:13:52 18662 [Note] InnoDB: Database physically writes the file full: wait...
2018-11-18 00:13:52 18662 [Note] InnoDB: Setting log file ./ib_logfile101 size to 48 MB
2018-11-18 00:13:52 18662 [Note] InnoDB: Setting log file ./ib_logfile1 size to 48 MB
2018-11-18 00:13:53 18662 [Note] InnoDB: Renaming log file ./ib_logfile101 to ./ib_logfile0
2018-11-18 00:13:53 18662 [Warning] InnoDB: New log files created, LSN=45781
2018-11-18 00:13:53 18662 [Note] InnoDB: Doublewrite buffer not found: creating new
2018-11-18 00:13:53 18662 [Note] InnoDB: Doublewrite buffer created
2018-11-18 00:13:53 18662 [Note] InnoDB: 128 rollback segment(s) are active.
2018-11-18 00:13:53 18662 [Warning] InnoDB: Creating foreign key constraint system tables.
2018-11-18 00:13:53 18662 [Note] InnoDB: Foreign key constraint system tables created
2018-11-18 00:13:53 18662 [Note] InnoDB: Creating tablespace and datafile system tables.
2018-11-18 00:13:53 18662 [Note] InnoDB: Tablespace and datafile system tables created.
2018-11-18 00:13:53 18662 [Note] InnoDB: Waiting for purge to start
2018-11-18 00:13:53 18662 [Note] InnoDB: 5.6.42 started; log sequence number 0
2018-11-18 00:13:53 18662 [Note] Binlog end
2018-11-18 00:13:53 18662 [Note] InnoDB: FTS optimize thread exiting.
2018-11-18 00:13:53 18662 [Note] InnoDB: Starting shutdown...
2018-11-18 00:13:55 18662 [Note] InnoDB: Shutdown completed; log sequence number 1625977
OK

Filling help tables...2018-11-18 00:13:55 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
2018-11-18 00:13:55 0 [Note] Ignoring --secure-file-priv value as server is running with --bootstrap.
2018-11-18 00:13:55 0 [Note] ./bin/mysqld (mysqld 5.6.42) starting as process 18686 ...
2018-11-18 00:13:55 18686 [Note] InnoDB: Using atomics to ref count buffer pool pages
2018-11-18 00:13:55 18686 [Note] InnoDB: The InnoDB memory heap is disabled
2018-11-18 00:13:55 18686 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
2018-11-18 00:13:55 18686 [Note] InnoDB: Memory barrier is not used
2018-11-18 00:13:55 18686 [Note] InnoDB: Compressed tables use zlib 1.2.11
2018-11-18 00:13:55 18686 [Note] InnoDB: Using Linux native AIO
2018-11-18 00:13:55 18686 [Note] InnoDB: Using CPU crc32 instructions
2018-11-18 00:13:55 18686 [Note] InnoDB: Initializing buffer pool, size = 128.0M
2018-11-18 00:13:55 18686 [Note] InnoDB: Completed initialization of buffer pool
2018-11-18 00:13:55 18686 [Note] InnoDB: Highest supported file format is Barracuda.
2018-11-18 00:13:55 18686 [Note] InnoDB: 128 rollback segment(s) are active.
2018-11-18 00:13:55 18686 [Note] InnoDB: Waiting for purge to start
2018-11-18 00:13:55 18686 [Note] InnoDB: 5.6.42 started; log sequence number 1625977
2018-11-18 00:13:55 18686 [Note] Binlog end
2018-11-18 00:13:55 18686 [Note] InnoDB: FTS optimize thread exiting.
2018-11-18 00:13:55 18686 [Note] InnoDB: Starting shutdown...
2018-11-18 00:13:57 18686 [Note] InnoDB: Shutdown completed; log sequence number 1625987
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 MySQL 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 iz2ze3g1c5ttso3f78zgo2z 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 manual for more instructions.

You can start the MySQL daemon with:

  cd . ; ./bin/mysqld_safe &

You can test the MySQL daemon with mysql-test-run.pl

  cd mysql-test ; perl mysql-test-run.pl

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

WARNING: Found existing config file ./my.cnf on the system.
Because this file might be in use, it was not replaced,
but was used in bootstrap (unless you used --defaults-file)
and when you later start the server.
The new default config file was created as ./my-new.cnf,
please compare it with your file and take the changes you need.

WARNING: Default config file /etc/my.cnf exists on the system
This file will be read by default by the MySQL server
If you do not want to use this, either remove it, or use the
--defaults-file argument to mysqld_safe when starting the server

[[email protected] mysql]# 

安裝完之後修改當前目錄擁有者為root使用者，修改data目錄擁有者為mysql：

chown -R root:root ./
chown -R mysql:mysql data

6、啟動mysql:

[[email protected] mysql]# ./support-files/mysql.server start                     
Starting MySQL.181118 00:23:52 mysqld_safe error: log-error set to '/var/log/mariadb/mariadb.log', however file don't exists. Create writable for user 'mysql'.
The server quit without updating PID file (/var/lib/mysql/i[FAILED]5ttso3f78zgo2z.pid).

上面啟動報錯，提示log檔案無許可權，我們可以通過更改配置修改log檔案指向，並建立一個log檔案來解決：

配置檔案：/etc/my.cnf

[mysqld_safe]                                                                                
log-error=/var/log/mariadb/mariadb.log                                                       
pid-file=/var/run/mariadb/mariadb.pid 

修改後：

[mysqld_safe]                                                                                
log-error=/usr/local/mysql/logs/mysqld.log                                                   
pid-file=/var/run/mysql/mysql.pid 

建立log檔案，並修改檔案許可權：

[[email protected] etc]# cd /usr/local/mysql/

[[email protected] mysql]# mkdir logs

[[email protected] mysql]# cd logs                                             

[[email protected] logs]# echo "" > /usr/local/mysql/logs/mysqld.log   

[[email protected] logs]# chown -R mysql:mysql /usr/local/mysql/logs/mysqld.log

重新執行啟動mysql命令：

[[email protected] mysql]# ./support-files/mysql.server start     
Starting MySQL.                                            [  OK  ]
[[email protected] mysql]# 

[OK].

7、修改密碼

[[email protected] mysql]# ./bin/mysqladmin -u root password 'root'               
./bin/mysqladmin: connect to server at 'localhost' failed
error: 'Can't connect to local MySQL server through socket '/tmp/mysql.sock' (2)'
Check that mysqld is running and that the socket: '/tmp/mysql.sock' exists!

[mysqld]                                                                                     
datadir=/var/lib/mysql                                                                       
socket=/var/lib/mysql/mysql.sock                                                             
# Disabling symbolic-links is recommended to prevent assorted security risks                 
symbolic-links=0                                                                             
# Settings user and group are ignored when systemd is used.                                  
# If you need to run mysqld under a different user or group,                                 
# customize your systemd unit file for mariadb according to the                              
# instructions in http://fedoraproject.org/wiki/Systemd 

修改後：

[mysqld]                                                                                     
basedir=/usr/local/mysql
datadir=/usr/local/mysql/data                                                                
socket=/usr/local/mysql/tmp/mysql.sock                                                       
# Disabling symbolic-links is recommended to prevent assorted security risks                 
symbolic-links=0                                                                             
# Settings user and group are ignored when systemd is used.                                  
# If you need to run mysqld under a different user or group,                                 
# customize your systemd unit file for mariadb according to the                              
# instructions in http://fedoraproject.org/wiki/Systemd