卸载阿里云的mysql_阿里云linux上，记一次mysql重装——卸载，安装 mysql 5.7
上一次的挖矿病毒可是搞惨我了，虽然勉强清掉了，但是不知道为什么mysql后来无法登录了！！！
找了一切办法来解决(from百度)，然并卵。
好吧，重装。
1. 备份
备份原来的数据库，里面有我的所有数据库脚本文件，一一拷出来
[root@jun ~]# cd /usr/local/mysql/share/
2.卸载
——参考小黑s
查看安装的mysql：
[root@ ~]# rpm -qa|grep -i mysql
停止mysql服务
[root@jun ~]# /usr/local/mysql/support-files/mysql.server stop
卸载删除mysql组件
rpm -ev mysql-*****
查看mysql文件夹信息
[root@jun ~]# whereis mysql
mysql: /usr/local/mysql /usr/local/mysql/bin/mysql
再 rm -rf 删除mysql对应文件夹
[root@jun ~]# rm -rf /usr/local/mysql /usr/local/mysql/bin/mysql
删除mysql用户名和用户组
[root@jun ~]# more /etc/passwd | grep mysql
[root@jun ~]# more /etc/shadow | grep mysql
[root@jun ~]# more /etc/group | grep mysql
[root@jun ~]# userdel mysql
[root@jun ~]# groupdel mysql
删除配置文件
[root@jun ~]# rm -f /etc/my.cnf /var/log/mysqld.log /var/run/mysqld/
3. 安装
我装的版本是mysql-5.7.22-linux-glibc2.12-x86_64.tar.gz
链接：https://pan.baidu.com/s/1ceU6_82jebSumi4hDRkk5Q 密码：rum8(若失效可在下面评论，看到我会更新链接)
1.下载完后上传到linux
2.解压 后移动到/usr/local/mysql下，顺便改名
[root@jun ~]# tar -zxvf mysql-5.7.22-linux-glibc2.12-x86_64.tar.gz
[root@jun ~]# mv mysql-5.7.22-linux-glibc2.12-x86_64 /usr/local/mysql
3.创建用户组，授权
[root@jun ~]# groupadd mysql
[root@jun ~]# useradd -r -g mysql mysql
[root@jun ~]# chown -R mysql mysql
[root@jun ~]# chgrp -R mysql mysql
4.创建配置文件，添加配置
[root@jun ~]# vim /etc/my.cnf
[client]
port = 3306
socket = /tmp/mysql.sock
[mysqld]
character_set_server=utf8
init_connect='SET NAMES utf8'
basedir=/usr/local/mysql
datadir=/usr/local/mysql/data
socket=/tmp/mysql.sock
#skip-grant-tables
log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid
lower_case_table_names = 1
sql_mode=STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION
max_connections=5000
default-time_zone = '+8:00'
~
~
~
~
~
~
5.安装libaio
[root@jun ~]# yum install libaio
6.添加日志文件，赋权
[root@jun ~]# vim /var/log/mysqld.log
[root@jun ~]# chmod 777 mysqld.log
[root@jun ~]# chown mysql:mysql mysqld.log
[root@jun ~]# cd /var/run/
[root@jun ~]# mkdir mysqld
[root@jun ~]# chmod 777 mysqld
[root@jun ~]# cd mysqld
[root@jun ~]# vim mysqld.pid
[root@jun ~]# chmod 777 mysqld.pid
[root@jun ~]# chown mysql:mysql mysqld.pid
7.初始化：
[root@jun ~]# /usr/local/mysql/bin/mysqld --initialize --user=mysql --basedir=/usr/local/mysql --datadir=/usr/local/mysql/data --lc_messages_dir=/usr/local/mysql/share --lc_messages=en_US
8.查看初始密码
[root@jun ~]# cat /var/log/mysqld.log
2018-12-04T13:30:57.037965Z 1 [Note] A temporary password is generated for root@localhost: znxw&zw1gvW+
9.启动服务
[root@jun ~]# /usr/local/mysql/support-files/mysql.server start
然后就是登录改密码了 /usr/local/mysql/bin/mysql -uroot -p初始密码
不过我到了这一步是进不去的，我是在/etc/my.cnf的[mysqld]
加了一句skip-grant-tables，取消验证然后再改密码
！！！又被搞了一次，不过这次到了这一步是可以进去的了，直接修改密码：
ALTER USER 'root'@'localhost'IDENTIFIED BY 'mimahere';
过程中遇到过的错误：
1.mysqld文件夹没有加权限
ERROR! The server quit without updating PID file (/var/run/mysqld/mysqld.pid).
2.初始化失败
[Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
[WARNING] mysql_install_db is deprecated. Please consider switching to mysqld --initialize
[ERROR] The data directory needs to be specified.
[ERROR] --initialize specified but the data directory has files in it. Aborting.
3.初始化没成功状态下启动服务，通过service mysqld start
mysqld: Error on realpath() on '/var/lib/mysql-files' (Error 2 - No such file or directory)
[ERROR] Failed to access directory for --secure-file-priv. Please make sure that directory exists and is accessible by MySQL Server. Supplied value : /var/lib/mysql-files
[ERROR] Aborting
4.data文件夹没有授权，没办法写
[ERROR] Failed to get stat for directory pointed out by --secure-file-priv
[ERROR] Aborting
5.第一次登录，密码错误，skip-grant-tables解决
mysql: [Warning] Using a password on the command line interface can be insecure.
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)