[系统运维] Mysql启动过程错误解决方案

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[系统运维]Mysql启动过程错误解决方案

1、下载 mysql5.7 的rpm包
wget https://dev.mysql.com/get/mysql57-community-release-el7-9.noarch.rpm

2.安装rpm包
rpm -ivh mysql57-community-release-el7-9.noarch.rpm

执行完成后会在/etc/yum.repos.d/目录下生成两个repo文件：mysql-community.repo、mysql-community-source.repo

ls /etc/yum.repos.d/

二、yum安装
注意：必须进入到 /etc/yum.repos.d/目录后再执行以下脚本
cd /etc/yum.repos.d/
安装
yum install mysql-server -y

报错：仓库 "MySQL 5.7 Community Server" 的 GPG 密钥已安装，但是不适用于此软件包。请检查仓库的公钥 URL 是否配置正确
成功处理的方法记录下。
rm /etc/pki/rpm-gpg/RPM-GPG-KEY-mysql?
rpm --import https://repo.mysql.com/RPM-GPG-KEY-mysql-2022?

1、启动
systemctl enable mysqld // 开机启动
systemctl start mysqld

2.获取临时登录密码（首次登录）
grep 'temporary password' /var/log/mysqld.log

3.登录
mysql -u root -p
然后输入密码（刚刚获取的临时密码）

4.重置密码
查看 mysql 初始的密码策略
SHOW VARIABLES LIKE 'validate_password%';
设置密码：长度大于8位，含大写字母、小写字母、数字、标点符号。如：Mysql:01
set password = password("yourpassword");?

四、远程访问
## 使用mysql库
use mysql;
## 修改user表中的Host，% 代表任意的客户端,可替换成具体IP地址。
update user set Host='%' where User='root'; ?
## 刷新
flush privileges;

-----------------------------------错误解决方案如下---------------------------------------

[root@localhost yum.repos.d]# systemctl enable mysqld
[root@localhost yum.repos.d]# cat /etc/my.cnf
# For advice on how to change settings please see
# http://dev.mysql.com/doc/refman/5.7/en/server-configuration-defaults.html

[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock

# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0

log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid
修改数据库存放目录
[root@localhost yum.repos.d]# mkdir -p /opt/mysql/data
您在 /var/spool/mail/root 中有新邮件
[root@localhost yum.repos.d]# vi /etc/my.cnf
[root@localhost yum.repos.d]#
[root@localhost yum.repos.d]#
[root@localhost yum.repos.d]# cd /var/lib/m
machines/ ? ? ?misc/ ? ? ? ? ?mlocate/ ? ? ? mysql/ ? ? ? ? mysql-files/ ? mysql-keyring/
[root@localhost yum.repos.d]# cd /var/lib/mysql
您在 /var/spool/mail/root 中有新邮件
[root@localhost mysql]# ls
[root@localhost mysql]# systemctl start mysqld
^C
您在 /var/spool/mail/root 中有新邮件
[root@localhost mysql]# ^C
[root@localhost mysql]# ^C
[root@localhost mysql]# systemctl status mysqld
● mysqld.service - MySQL Server
? ?Loaded: loaded (/usr/lib/systemd/system/mysqld.service; enabled; vendor preset: disabled)
? ?Active: activating (start-pre) since 一 2022-04-25 13:34:17 CST; 1min 57s ago
? ? ?Docs: man:mysqld(8)
? ? ? ? ? ?http://dev.mysql.com/doc/refman/en/using-systemd.html
? Control: 24343 (mysqld_pre_syst)
? ? Tasks: 28
? ?CGroup: /system.slice/mysqld.service
? ? ? ? ? ?└─control
? ? ? ? ? ? ?├─24343 /bin/bash /usr/bin/mysqld_pre_systemd
? ? ? ? ? ? ?└─24373 /usr/sbin/mysqld --initialize --datadir=/opt/mysql/data --user=mysql --init-file=/var/lib/mysql-files/install-...

4月 25 13:34:17 localhost.localdomain systemd[1]: Starting MySQL Server...
[root@localhost mysql]# grep 'temporary password' /var/log/mysqld.log
2022-04-25T05:34:33.968404Z 1 [Note] A temporary password is generated for root@localhost: FKlYFfSM2q<!
[root@localhost mysql]# mysql -u root -p
Enter password:
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)
您在 /var/spool/mail/root 中有新邮件
[root@localhost mysql]# mysql -u root -p
Enter password:
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)
[root@localhost mysql]# 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.

4月 25 13:39:24 localhost.localdomain systemd[1]: mysqld.service holdoff time over, scheduling restart.
4月 25 13:39:24 localhost.localdomain systemd[1]: Stopped MySQL Server.
4月 25 13:39:24 localhost.localdomain systemd[1]: Starting MySQL Server...
[root@localhost mysql]# ?lsof -i:3306
[root@localhost mysql]# systemctl stop mysqld
您在 /var/spool/mail/root 中有新邮件
[root@localhost mysql]# 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@localhost mysql]# ?vi /var/log/mysqld.log
查看日志发现
1)错误
The innodb_system data file 'ibdata1' must be writable
字面意思：’ibdata1必须可写
那么解决方案自然是更改对应权限
通过yum安装的话，
5.7版本以前是
chmod -R 777 /usr/local/mysql/data/
5.7版本以后是
chmod -R 777 /var/lib/mysql

如果不是通过yum安装的话：
find / -name ibdata1
找到对应目录更改权限~
2）警告
Can't create test file /opt/mysql/data/localhost.lower-test
第一，selinux，记得当年字符界面安装redhat(很古老的操作系统么。。。)的时候，有这么一个选项，通常都听取前辈的建议，
改变默认值以不安装它。但如果你恰好要操作的这台机器开着selinux，它确实能够使你的mysql无法在新目标位置进行mysql_install_db的操作，
并爆出标题所示的警告。一个简单的解决办法是使用命令暂时关闭selinux，以便让你的操作可以继续下去

setenforce 0

但最好使用一个永久方法，以便在重启后继续不要这货。
修改/etc/selinux/config文件中设置SELINUX=disabled ，然后重启或等待下次重启。

第二，apparmor，这个坑爹货和selinux一样的坑爹，它也对mysql所能使用的目录权限做了限制
在 /etc/apparmor.d/usr.sbin.mysqld 这个文件中，有这两行，规定了mysql使用的数据文件路径权限
/var/lib/mysql/ r,
/var/lib/mysql/** rwk,
/var/lib/mysql/就是之前mysql安装的数据文件默认路径，apparmor控制这里mysqld可以使用的目录的权限
把数据文件移动到/data/mysql下，那么为了使mysqld可以使用/data/mysql这个目录，照上面那两

[root@localhost mysql]#
[root@localhost mysql]#
[root@localhost mysql]# chmod -R 777 /opt/mysql/
[root@localhost mysql]# 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@localhost mysql]# systemctl stop mysqld
[root@localhost mysql]# 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@localhost mysql]# ?vi /var/log/mysqld.log
您在 /var/spool/mail/root 中有新邮件
[root@localhost mysql]#
[root@localhost mysql]#
[root@localhost mysql]#
[root@localhost mysql]# vi ?/etc/apparmor.d/usr.sbin.mysqld
[root@localhost mysql]# cat ? /etc/apparmor.d
cat: /etc/apparmor.d: 没有那个文件或目录
[root@localhost mysql]# cd ? /etc/apparmor.d
-bash: cd: /etc/apparmor.d: 没有那个文件或目录
[root@localhost mysql]# ?vi /var/log/mysqld.log
您在 /var/spool/mail/root 中有新邮件
[root@localhost mysql]#
[root@localhost mysql]#
[root@localhost mysql]# setenforce 0
[root@localhost mysql]# systemctl start mysqld
[root@localhost mysql]# ?lsof -i:3306
COMMAND ? PID ?USER ? FD ? TYPE ?DEVICE SIZE/OFF NODE NAME
mysqld ?31934 mysql ? 21u ?IPv6 2943808 ? ? ?0t0 ?TCP *:mysql (LISTEN)
[root@localhost mysql]# grep 'temporary password' /var/log/mysqld.log
2022-04-25T05:34:33.968404Z 1 [Note] A temporary password is generated for root@localhost: FKlYFfSM2q<!
[root@localhost mysql]# mysql -u root -p
Enter password:
Welcome to the MySQL monitor. ?Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.7.37

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 'validate_password%';
ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement.
mysql> set password = password("111111");
ERROR 1819 (HY000): Your password does not satisfy the current policy requirements
mysql> set password = password("xx#123456");
ERROR 1819 (HY000): Your password does not satisfy the current policy requirements
mysql> set password = password("Xxx@#123456");
Query OK, 0 rows affected, 1 warning (0.03 sec)

mysql> use mysql;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed
mysql> update user set Host='%' where User='root';
Query OK, 1 row affected (0.04 sec)
Rows matched: 1 ?Changed: 1 ?Warnings: 0

mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)

mysql>
?