CentOS7 安装 MySQL 和简单优化
本篇文章主要记录在 CentOS7 下通过 rpm 安装 MySQL，并且进行简单的配置优化。
[0x0]环境及其软件介绍
- 操作系统：CentOS7.0 纯净版
- MySQL 版本：5.7.16
[0x1]关闭 SELinux
SELinux(Security-Enhanced Linux) 是美国国家安全局（NSA）对于强制访问控制的实现，是 Linux 历史上最杰出的新安全子系统。在这种访问控制体系的限制下，进程只能访问那些在他的任务中所需要文件。SELinux 默认安装在 Fedora 和 Red Hat Enterprise Linux 上。虽然 SELinux 很好用，但是在多数情况我们还是将其关闭，因为在不了解其机制的情况下使用 SELinux 会导致软件安装或者应用部署失败。
一般如果使用云服务器，已经默认关闭了该服务，如果是虚拟机自己安装 CentOS 的话，那么需要自己手动关闭。如果不关闭，则影响后面的操作。
- 查看 selinux 的模式
[root@virtual data]# getenforce
Enforcing
[root@virtual data]#
- 关闭 selinux
- 永久性关闭
永久性关闭则需要重启服务器后生效
保存文件，然后重启服务器吧。# vim /etc/selinux/config #编辑这个文件，下面修改的内容 #============================================================ # This file controls the state of SELinux on the system. # SELINUX= can take one of these three values: # enforcing - SELinux security policy is enforced. # permissive - SELinux prints warnings instead of enforcing. # disabled - No SELinux policy is loaded. #SELINUX=enforcing #这个是系统默认的 SELINUX=disabled #这是自己修改的,表示禁用该服务 # SELINUXTYPE= can take one of three two values: # targeted - Targeted processes are protected, # minimum - Modification of targeted policy. Only selected processes are protected. # mls - Multi Level Security protection. SELINUXTYPE=targeted- 临时性关闭
临时性关闭仅对当前有效且立即生效，重启服务器之后无效。
setenforce 0命令表示设置 selinux 为 permissive 模式（即关闭）；
setenforce 1命令表示设置 selinux 为 enforcing 模式（即开启）
- 永久性关闭
[0x2]下载 MySQL
MySQL 的官网下载地址是 http://dev.mysql.com/downloads/mysql/，选择 Red Hat Enterprise Linux / Oracle Linux（因为 CentOS 属于 RHEL 的一个分支），如下图所示
然后下面选择 CentOS7 的全家桶，选择全家桶比较方便，当安装的时候如果提示缺少包，一般可以在全家桶里直接找到的。
老套路，可以直接到微云下载（密码：yv8Fib）。
将下载成功 mysql-5.7.16-1.el7.x86_64.rpm-bundle.tar 上传到您的服务器，下面就准备开始安装了。
[0x3]安装 MySQL
首先将上传的 MySQL mysql-5.7.16-1.el7.x86_64.rpm-bundle.tar 解压出来。
[root@virtual mysql]# ls
mysql-5.7.16-1.el7.x86_64.rpm-bundle.tar
[root@virtual mysql]# tar xvf mysql-5.7.16-1.el7.x86_64.rpm-bundle.tar
mysql-community-libs-compat-5.7.16-1.el7.x86_64.rpm
mysql-community-devel-5.7.16-1.el7.x86_64.rpm
mysql-community-minimal-debuginfo-5.7.16-1.el7.x86_64.rpm
mysql-community-libs-5.7.16-1.el7.x86_64.rpm
mysql-community-common-5.7.16-1.el7.x86_64.rpm
mysql-community-embedded-compat-5.7.16-1.el7.x86_64.rpm
mysql-community-test-5.7.16-1.el7.x86_64.rpm
mysql-community-embedded-devel-5.7.16-1.el7.x86_64.rpm
mysql-community-server-minimal-5.7.16-1.el7.x86_64.rpm
mysql-community-server-5.7.16-1.el7.x86_64.rpm
mysql-community-client-5.7.16-1.el7.x86_64.rpm
mysql-community-embedded-5.7.16-1.el7.x86_64.rpm
[root@virtual mysql]#
安装 MySQL 数据库的服务器版本，即 mysql-community-server-5.7.16-1.el7.x86_64.rpm，安装命令这里使用 yum localinstall，该命令会自动分析软件依赖包，非常的方便。
[root@virtual mysql]# yum localinstall mysql-community-server-
mysql-community-server-5.7.16-1.el7.x86_64.rpm mysql-community-server-minimal-5.7.16-1.el7.x86_64.rpm
[root@virtual mysql]# yum localinstall mysql-community-server-5.7.16-1.el7.x86_64.rpm
Loaded plugins: fastestmirror
Examining mysql-community-server-5.7.16-1.el7.x86_64.rpm: mysql-community-server-5.7.16-1.el7.x86_64
Marking mysql-community-server-5.7.16-1.el7.x86_64.rpm to be installed
Resolving Dependencies
--> Running transaction check
---> Package mysql-community-server.x86_64 0:5.7.16-1.el7 will be installed
--> Processing Dependency: mysql-community-common(x86-64) = 5.7.16-1.el7 for package: mysql-community-server-5.7.16-1.el7.x86_64
Loading mirror speeds from cached hostfile
* base: mirrors.aliyun.com
* extras: mirrors.aliyun.com
* updates: mirrors.yun-idc.com
--> Processing Dependency: mysql-community-client(x86-64) >= 5.7.9 for package: mysql-community-server-5.7.16-1.el7.x86_64
--> Processing Dependency: net-tools for package: mysql-community-server-5.7.16-1.el7.x86_64
--> Running transaction check
---> Package mysql-community-server.x86_64 0:5.7.16-1.el7 will be installed
--> Processing Dependency: mysql-community-common(x86-64) = 5.7.16-1.el7 for package: mysql-community-server-5.7.16-1.el7.x86_64
--> Processing Dependency: mysql-community-client(x86-64) >= 5.7.9 for package: mysql-community-server-5.7.16-1.el7.x86_64
---> Package net-tools.x86_64 0:2.0-0.17.20131004git.el7 will be installed
--> Finished Dependency Resolution
Error: Package: mysql-community-server-5.7.16-1.el7.x86_64 (/mysql-community-server-5.7.16-1.el7.x86_64)
Requires: mysql-community-common(x86-64) = 5.7.16-1.el7
Error: Package: mysql-community-server-5.7.16-1.el7.x86_64 (/mysql-community-server-5.7.16-1.el7.x86_64)
Requires: mysql-community-client(x86-64) >= 5.7.9
You could try using --skip-broken to work around the problem
You could try running: rpm -Va --nofiles --nodigest
[root@virtual mysql]#
根据上面的错误信息可以知道，安装 MySQL 服务器 mysql-community-server-5.7.16-1.el7.x86_64.rpm 需要先安装 mysql-community-client(x86-64) 软件，这个时候体现出全家桶的好处，发现全家桶里面带有这个软件，所以直接先安装这个软件即可。
[root@virtual mysql]# yum localinstall mysql-community-client-5.7.16-1.el7.x86_64.rpm
Loaded plugins: fastestmirror
Examining mysql-community-client-5.7.16-1.el7.x86_64.rpm: mysql-community-client-5.7.16-1.el7.x86_64
Marking mysql-community-client-5.7.16-1.el7.x86_64.rpm to be installed
Resolving Dependencies
--> Running transaction check
---> Package mysql-community-client.x86_64 0:5.7.16-1.el7 will be installed
--> Processing Dependency: mysql-community-libs(x86-64) >= 5.7.9 for package: mysql-community-client-5.7.16-1.el7.x86_64
Loading mirror speeds from cached hostfile
* base: mirrors.aliyun.com
* extras: mirrors.aliyun.com
* updates: mirrors.yun-idc.com
--> Finished Dependency Resolution
Error: Package: mysql-community-client-5.7.16-1.el7.x86_64 (/mysql-community-client-5.7.16-1.el7.x86_64)
Requires: mysql-community-libs(x86-64) >= 5.7.9
You could try using --skip-broken to work around the problem
You could try running: rpm -Va --nofiles --nodigest
[root@virtual mysql]#
套路出来了，根据错误信息，很显然先安装 mysql-community-libs(x86-64)，走起：
[root@virtual mysql]# yum localinstall mysql-community-libs-
mysql-community-libs-5.7.16-1.el7.x86_64.rpm mysql-community-libs-compat-5.7.16-1.el7.x86_64.rpm
[root@virtual mysql]# yum localinstall mysql-community-libs-5.7.16-1.el7.x86_64.rpm
Loaded plugins: fastestmirror
Examining mysql-community-libs-5.7.16-1.el7.x86_64.rpm: mysql-community-libs-5.7.16-1.el7.x86_64
Marking mysql-community-libs-5.7.16-1.el7.x86_64.rpm to be installed
Resolving Dependencies
--> Running transaction check
---> Package mariadb-libs.x86_64 1:5.5.44-2.el7.centos will be obsoleted
--> Processing Dependency: libmysqlclient.so.18()(64bit) for package: 2:postfix-2.10.1-6.el7.x86_64
Loading mirror speeds from cached hostfile
* base: mirrors.aliyun.com
* extras: mirrors.aliyun.com
* updates: mirrors.yun-idc.com
--> Processing Dependency: libmysqlclient.so.18(libmysqlclient_18)(64bit) for package: 2:postfix-2.10.1-6.el7.x86_64
---> Package mysql-community-libs.x86_64 0:5.7.16-1.el7 will be obsoleting
--> Processing Dependency: mysql-community-common(x86-64) >= 5.7.9 for package: mysql-community-libs-5.7.16-1.el7.x86_64
--> Running transaction check
---> Package mariadb-libs.x86_64 1:5.5.44-2.el7.centos will be updated
---> Package mariadb-libs.x86_64 1:5.5.50-1.el7_2 will be an update
---> Package mysql-community-libs.x86_64 0:5.7.16-1.el7 will be obsoleting
--> Processing Dependency: mysql-community-common(x86-64) >= 5.7.9 for package: mysql-community-libs-5.7.16-1.el7.x86_64
Removing mariadb-libs.x86_64 1:5.5.50-1.el7_2 - u due to obsoletes from mysql-community-libs.x86_64 0:5.7.16-1.el7 - u
--> Restarting Dependency Resolution with new changes.
--> Running transaction check
---> Package mariadb-libs.x86_64 1:5.5.50-1.el7_2 will be an update
--> Processing Dependency: libmysqlclient.so.18(libmysqlclient_18)(64bit) for package: 2:postfix-2.10.1-6.el7.x86_64
--> Processing Dependency: libmysqlclient.so.18()(64bit) for package: 2:postfix-2.10.1-6.el7.x86_64
---> Package mysql-community-libs.x86_64 0:5.7.16-1.el7 will be obsoleting
--> Processing Dependency: mysql-community-common(x86-64) >= 5.7.9 for package: mysql-community-libs-5.7.16-1.el7.x86_64
--> Running transaction check
---> Package mariadb-libs.x86_64 1:5.5.47-1.el7_2 will be an update
---> Package mysql-community-libs.x86_64 0:5.7.16-1.el7 will be obsoleting
--> Processing Dependency: mysql-community-common(x86-64) >= 5.7.9 for package: mysql-community-libs-5.7.16-1.el7.x86_64
Removing mariadb-libs.x86_64 1:5.5.47-1.el7_2 - u due to obsoletes from mysql-community-libs.x86_64 0:5.7.16-1.el7 - u
--> Restarting Dependency Resolution with new changes.
--> Running transaction check
---> Package mariadb-libs.x86_64 1:5.5.47-1.el7_2 will be an update
--> Processing Dependency: libmysqlclient.so.18(libmysqlclient_18)(64bit) for package: 2:postfix-2.10.1-6.el7.x86_64
--> Processing Dependency: libmysqlclient.so.18()(64bit) for package: 2:postfix-2.10.1-6.el7.x86_64
---> Package mysql-community-libs.x86_64 0:5.7.16-1.el7 will be obsoleting
--> Processing Dependency: mysql-community-common(x86-64) >= 5.7.9 for package: mysql-community-libs-5.7.16-1.el7.x86_64
--> Finished Dependency Resolution
Error: Package: mysql-community-libs-5.7.16-1.el7.x86_64 (/mysql-community-libs-5.7.16-1.el7.x86_64)
Requires: mysql-community-common(x86-64) >= 5.7.9
Error: Package: 2:postfix-2.10.1-6.el7.x86_64 (@anaconda)
Requires: libmysqlclient.so.18(libmysqlclient_18)(64bit)
Removing: 1:mariadb-libs-5.5.44-2.el7.centos.x86_64 (@anaconda)
libmysqlclient.so.18(libmysqlclient_18)(64bit)
Obsoleted By: mysql-community-libs-5.7.16-1.el7.x86_64 (/mysql-community-libs-5.7.16-1.el7.x86_64)
Not found
Updated By: 1:mariadb-libs-5.5.50-1.el7_2.x86_64 (updates)
libmysqlclient.so.18(libmysqlclient_18)(64bit)
Available: 1:mariadb-libs-5.5.47-1.el7_2.x86_64 (updates)
libmysqlclient.so.18(libmysqlclient_18)(64bit)
Error: Package: 2:postfix-2.10.1-6.el7.x86_64 (@anaconda)
Requires: libmysqlclient.so.18()(64bit)
Removing: 1:mariadb-libs-5.5.44-2.el7.centos.x86_64 (@anaconda)
libmysqlclient.so.18()(64bit)
Obsoleted By: mysql-community-libs-5.7.16-1.el7.x86_64 (/mysql-community-libs-5.7.16-1.el7.x86_64)
~libmysqlclient.so.20()(64bit)
Updated By: 1:mariadb-libs-5.5.50-1.el7_2.x86_64 (updates)
libmysqlclient.so.18()(64bit)
Available: 1:mariadb-libs-5.5.47-1.el7_2.x86_64 (updates)
libmysqlclient.so.18()(64bit)
You could try using --skip-broken to work around the problem
You could try running: rpm -Va --nofiles --nodigest
[root@virtual mysql]#
这次出现的错误不太一样，出现了两个错误，一个错误仍然提示缺少依赖包,mysql-community-common(x86-64)，另外一个错误是与 mariadb-libs-5.5.44-2.el7.centos.x86_64 发生冲突，所以需要卸载这个软件。
[root@virtual mysql]# yum remove mariadb-libs
Loaded plugins: fastestmirror
Resolving Dependencies
--> Running transaction check
---> Package mariadb-libs.x86_64 1:5.5.50-1.el7_2 will be erased
--> Processing Dependency: libmysqlclient.so.18()(64bit) for package: 2:postfix-2.10.1-6.el7.x86_64
--> Processing Dependency: libmysqlclient.so.18(libmysqlclient_18)(64bit) for package: 2:postfix-2.10.1-6.el7.x86_64
--> Running transaction check
---> Package postfix.x86_64 2:2.10.1-6.el7 will be erased
--> Finished Dependency Resolution
Dependencies Resolved
=========================================================================================================================================================
Package Arch Version Repository Size
=========================================================================================================================================================
Removing:
mariadb-libs x86_64 1:5.5.50-1.el7_2 @updates 4.4 M
Removing for dependencies:
postfix x86_64 2:2.10.1-6.el7 @anaconda 12 M
Transaction Summary
=========================================================================================================================================================
Remove 1 Package (+1 Dependent package)
Installed size: 17 M
Is this ok [y/N]: y
Downloading packages:
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
Erasing : 2:postfix-2.10.1-6.el7.x86_64 1/2
Erasing : 1:mariadb-libs-5.5.50-1.el7_2.x86_64 2/2
Verifying : 1:mariadb-libs-5.5.50-1.el7_2.x86_64 1/2
Verifying : 2:postfix-2.10.1-6.el7.x86_64 2/2
Removed:
mariadb-libs.x86_64 1:5.5.50-1.el7_2
Dependency Removed:
postfix.x86_64 2:2.10.1-6.el7
Complete!
[root@virtual mysql]#
卸载完成后解决最后一个依赖问题 mysql-community-common-5.7.16-1.el7.x86_64.rpm
[root@virtual mysql]# yum localinstall mysql-community-common-5.7.16-1.el7.x86_64.rpm
Loaded plugins: fastestmirror
Examining mysql-community-common-5.7.16-1.el7.x86_64.rpm: mysql-community-common-5.7.16-1.el7.x86_64
Marking mysql-community-common-5.7.16-1.el7.x86_64.rpm to be installed
Resolving Dependencies
--> Running transaction check
---> Package mysql-community-common.x86_64 0:5.7.16-1.el7 will be installed
--> Finished Dependency Resolution
Dependencies Resolved
=========================================================================================================================================================
Package Arch Version Repository Size
=========================================================================================================================================================
Installing:
mysql-community-common x86_64 5.7.16-1.el7 /mysql-community-common-5.7.16-1.el7.x86_64 2.5 M
Transaction Summary
=========================================================================================================================================================
Install 1 Package
Total size: 2.5 M
Installed size: 2.5 M
Is this ok [y/d/N]: y
Downloading packages:
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
Installing : mysql-community-common-5.7.16-1.el7.x86_64 1/1
Verifying : mysql-community-common-5.7.16-1.el7.x86_64 1/1
Installed:
mysql-community-common.x86_64 0:5.7.16-1.el7
Complete!
[root@virtual mysql]#
接下来就是倒着安装相关依赖，首先安装 mysql-community-libs-5.7.16-1.el7.x86_64.rpm
[root@virtual mysql]# yum localinstall mysql-community-libs-5.7.16-1.el7.x86_64.rpm
Loaded plugins: fastestmirror
Examining mysql-community-libs-5.7.16-1.el7.x86_64.rpm: mysql-community-libs-5.7.16-1.el7.x86_64
Marking mysql-community-libs-5.7.16-1.el7.x86_64.rpm to be installed
Resolving Dependencies
--> Running transaction check
---> Package mysql-community-libs.x86_64 0:5.7.16-1.el7 will be installed
--> Finished Dependency Resolution
Dependencies Resolved
=========================================================================================================================================================
Package Arch Version Repository Size
=========================================================================================================================================================
Installing:
mysql-community-libs x86_64 5.7.16-1.el7 /mysql-community-libs-5.7.16-1.el7.x86_64 9.4 M
Transaction Summary
=========================================================================================================================================================
Install 1 Package
Total size: 9.4 M
Installed size: 9.4 M
Is this ok [y/d/N]: y
Downloading packages:
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
Installing : mysql-community-libs-5.7.16-1.el7.x86_64 1/1
Verifying : mysql-community-libs-5.7.16-1.el7.x86_64 1/1
Installed:
mysql-community-libs.x86_64 0:5.7.16-1.el7
Complete!
[root@virtual mysql]#
继续安装 mysql-community-client-5.7.16-1.el7.x86_64.rpm
[root@virtual mysql]# yum localinstall mysql-community-client-5.7.16-1.el7.x86_64.rpm
Loaded plugins: fastestmirror
Examining mysql-community-client-5.7.16-1.el7.x86_64.rpm: mysql-community-client-5.7.16-1.el7.x86_64
Marking mysql-community-client-5.7.16-1.el7.x86_64.rpm to be installed
Resolving Dependencies
--> Running transaction check
---> Package mysql-community-client.x86_64 0:5.7.16-1.el7 will be installed
--> Finished Dependency Resolution
Dependencies Resolved
=========================================================================================================================================================
Package Arch Version Repository Size
=========================================================================================================================================================
Installing:
mysql-community-client x86_64 5.7.16-1.el7 /mysql-community-client-5.7.16-1.el7.x86_64 106 M
Transaction Summary
=========================================================================================================================================================
Install 1 Package
Total size: 106 M
Installed size: 106 M
Is this ok [y/d/N]: y
Downloading packages:
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
Installing : mysql-community-client-5.7.16-1.el7.x86_64 1/1
Verifying : mysql-community-client-5.7.16-1.el7.x86_64 1/1
Installed:
mysql-community-client.x86_64 0:5.7.16-1.el7
Complete!
[root@virtual mysql]#
word 的天哪，终于到了安装 mysql-community-server-5.7.16-1.el7.x86_64.rpm 的时候了。
[root@virtual mysql]# yum localinstall mysql-community-server-5.7.16-1.el7.x86_64.rpm
Loaded plugins: fastestmirror
Examining mysql-community-server-5.7.16-1.el7.x86_64.rpm: mysql-community-server-5.7.16-1.el7.x86_64
Marking mysql-community-server-5.7.16-1.el7.x86_64.rpm to be installed
Resolving Dependencies
--> Running transaction check
---> Package mysql-community-server.x86_64 0:5.7.16-1.el7 will be installed
--> Processing Dependency: net-tools for package: mysql-community-server-5.7.16-1.el7.x86_64
Loading mirror speeds from cached hostfile
* base: mirrors.aliyun.com
* extras: mirrors.aliyun.com
* updates: mirrors.yun-idc.com
--> Running transaction check
---> Package net-tools.x86_64 0:2.0-0.17.20131004git.el7 will be installed
--> Finished Dependency Resolution
Dependencies Resolved
=========================================================================================================================================================
Package Arch Version Repository Size
=========================================================================================================================================================
Installing:
mysql-community-server x86_64 5.7.16-1.el7 /mysql-community-server-5.7.16-1.el7.x86_64 691 M
Installing for dependencies:
net-tools x86_64 2.0-0.17.20131004git.el7 base 304 k
Transaction Summary
=========================================================================================================================================================
Install 1 Package (+1 Dependent package)
Total size: 691 M
Total download size: 304 k
Installed size: 692 M
Is this ok [y/d/N]: y
Downloading packages:
net-tools-2.0-0.17.20131004git.el7.x86_64.rpm | 304 kB 00:00:06
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
Installing : net-tools-2.0-0.17.20131004git.el7.x86_64 1/2
Installing : mysql-community-server-5.7.16-1.el7.x86_64 2/2
Verifying : mysql-community-server-5.7.16-1.el7.x86_64 1/2
Verifying : net-tools-2.0-0.17.20131004git.el7.x86_64 2/2
Installed:
mysql-community-server.x86_64 0:5.7.16-1.el7
Dependency Installed:
net-tools.x86_64 0:2.0-0.17.20131004git.el7
Complete!
[root@virtual mysql]#
至此 MySQL 的服务器软件安装完毕，并且一并的安装了 MySQL 客户端软件。
[0x4]启动 MySQL
默认安装完成后可以检查下 MySQL 是否启动了。
[root@virtual mysql]# systemctl status mysqld.service
● mysqld.service - MySQL Server
Loaded: loaded (/usr/lib/systemd/system/mysqld.service; enabled; vendor preset: disabled)
Active: inactive (dead)
[root@virtual mysql]#
Active: inactive (dead)表示没启动，所以先启动 MySQL 服务。
[root@virtual mysql]# systemctl start mysqld
[root@virtual mysql]# systemctl status mysqld
● mysqld.service - MySQL Server
Loaded: loaded (/usr/lib/systemd/system/mysqld.service; enabled; vendor preset: disabled)
Active: active (running) since Wed 2016-11-23 21:36:10 CST; 31s ago
Process: 12769 ExecStart=/usr/sbin/mysqld --daemonize --pid-file=/var/run/mysqld/mysqld.pid $MYSQLD_OPTS (code=exited, status=0/SUCCESS)
Process: 12752 ExecStartPre=/usr/bin/mysqld_pre_systemd (code=exited, status=0/SUCCESS)
Main PID: 12773 (mysqld)
CGroup: /system.slice/mysqld.service
└─12773 /usr/sbin/mysqld --daemonize --pid-file=/var/run/mysqld/mysqld.pid
Nov 23 21:36:09 virtual.m1 systemd[1]: Starting MySQL Server...
Nov 23 21:36:10 virtual.m1 systemd[1]: Started MySQL Server.
[root@virtual mysql]#
Active: active (running) 表示启动成功了。
[0x5]登录 MySQL
好像 MySQL 每个版本对于 root 的初始密码存放目录有变更，MySQL5.7 的 root 初始密码位置在 /var/log/mysqld.log，查看初始密码
[root@virtual mysql]# cat /var/log/mysqld.log | grep 'password'
2016-11-23T13:35:47.379026Z 1 [Note] A temporary password is generated for root@localhost: 8Elr*VgB7I?E
2016-11-23T13:36:08.112362Z 0 [Note] Shutting down plugin 'validate_password'
2016-11-23T13:36:09.489444Z 0 [Note] Shutting down plugin 'sha256_password'
2016-11-23T13:36:09.489450Z 0 [Note] Shutting down plugin 'mysql_native_password'
[root@virtual mysql]#
有了 root 初始密码就可以登录了。
[root@virtual mysql]# mysql -uroot -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.7.16
Copyright (c) 2000, 2016, 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>
这个时候还不能正常使用 MySQL，会提示先修改 root 密码。
mysql> show databases;
ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement.
mysql>
以前的 password() 函数将会被抛弃，官方建议使用下面的命令来修改密码 ALTER USER 'root'@'localhost' IDENTIFIED BY 'new_password';；同时，如果你设置的密码过于简单也会报错。
mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY 'root123';
ERROR 1819 (HY000): Your password does not satisfy the current policy requirements
mysql>
对于 MySQL5.7 用户的密码规则大致如下：
- 长度要大于 8
- 同时要有数字，大小写，特殊字符
也可以暂时不在这里设置 root 密码，下面的安装优化里也会涉及到 root 密码的修改。
PS：MySQL5.6 的 root 初始密码位置 /root/.mysql_secret
[0x6]加强 MySQL 安全
默认安装完 MySQL 服务器之后，一般需要执行这个脚本 mysql_secure_installation，这里就会涉及到 root 的密码修改。
[root@virtual mysql]# mysql_secure_installation
Securing the MySQL server deployment.
Enter password for user root:
The existing password for the user account root has expired. Please set a new password.
New password:
Re-enter new password:
Sorry, passwords do not match.
New password:
Re-enter new password:
The 'validate_password' plugin is installed on the server.
The subsequent steps will run with the existing configuration
of the plugin.
Using existing password for root.
Estimated strength of the password: 100
Change the password for root ? ((Press y|Y for Yes, any other key for No) : y
New password:
Re-enter new password:
Estimated strength of the password: 100
Do you wish to continue with the password provided?(Press y|Y for Yes, any other key for No) : y
By default, a MySQL installation has an anonymous user,
allowing anyone to log into MySQL 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? (Press y|Y for Yes, any other key for No) : 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? (Press y|Y for Yes, any other key for No) : y
Success.
By default, MySQL 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? (Press y|Y for Yes, any other key for No) : 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? (Press y|Y for Yes, any other key for No) : y
Success.
All done!
[root@virtual mysql]#
下面列出 mysql_secure_installation 做的事情
- Set root password? [Y/n] Y
- Remove anonymous users? [Y/n] Y
- Disallow root login remotely? [Y/n] Y
- Remove test database and access to it? [Y/n] Y
- Reload privilege tables now? [Y/n] Y
其中设置 root 密码根据情况而来吧，可以修改也可以不修改。
[0x7]设置默认字符集
一般都是设置为 utf8，MySQL 的配置文件路径是 /etc/my.cnf，下面就是设置字符集的相关的配置。
# vim /etc/my.cnf
[mysqld] #下面的配置是属于mysqld的，所以一定要配置在这个下面
#====设置服务端字符集====
#设置数据库字符集UTF8
character-set-server=utf8
#设置数据库字符集排序规则，注意要和character-set-server对应
collation-server=utf8_general_ci
#设置连接是的字符集
init-connect= 'SET NAMES utf8'
保存配置文件，然后重启 MySQL(systemctl restart mysqld)，然后登录 MySQL，查看现在的字符集。
[root@virtual ~]# mysql -uroot -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 6
Server version: 5.7.16 MySQL Community Server (GPL)
Copyright (c) 2000, 2016, 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 '%character%';
+--------------------------+----------------------------+
| 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 (0.10 sec)
mysql>
[0x8]修改 MySQL 数据目录
迁移数据库目录 MySQL 数据库默认路径 /var/lib/mysql，实际工作中，常常需要定制数据库路径，比如 /data/mysql，或者 /opt/mysql，一般是单独的数据盘或者分区，这样有利于性能调优和保护数据安全，同时也方便进行维护。
- 首先在数据盘创建一个目录专门用来存放 MySQL 的数据的
mkdir -p /data/mysql - 分配目录的权限
chown -R mysql:mysql /data/mysql - 关闭 MySQL 服务
systemctl stop mysqld - 编辑 MySQL 配置文件
[mysqld]
#下面是系统默认的数据目录位置
#datadir=/var/lib/mysql
#下面这个是修改后的数据目录位置
datadir=/data/mysql
#socket=/var/lib/mysql/mysql.sock
socket=/data/mysql/mysql.sock
- 迁移数据，即将
/var/lib/mysql下的所有数据移动到/data/mysql下，执行命令mv /var/lib/mysql/* /data/mysql/
这个时候如果执行重启命令，会提示错误。
[root@virtual data]# systemctl start mysqld
Job for mysqld.service failed because the control process exited with error code. See "systemctl status mysqld.service" and "journalctl -xe" for details.
[root@virtual data]#
查看错误日志，看到其中有这样的日志 2016-11-24T14:01:36.732839Z 0 [ERROR] InnoDB: Operating system error number 13 in a file operation. 突然明白没有关闭 SELinux 服务，所以如果按照这个笔记来的话，则不会出现这个问题啦。关闭 SELinux 然后重启服务器，就可以正常启动 MySQL 服务了。
[0x9]结束
至此 MySQL 的安装和简单优化操作完成了，总体来看，MySQL 的安装比较简单，繁琐的地方还是在配置，如果想要优化的更好的话，那还有一坨事情等着呢，不过这样已经满足一般需求了。
未完待续(To be Continued...)
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