报错

[root@iZj6c1drl65inbvxsn0vj5Z /]# 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.

解决

方法一

  1. 先去/etc/my.cnf文件中找到你的mysql目录

发现没有配置文件，里面只有一个路径

[root@iZj6c1drl65inbvxsn0vj5Z /]# cat /etc/my.cnf
#
# This group is read both both by the client and the server
# use it for options that affect everything
#
[client-server]

#
# include all files from the config directory
#
!includedir /etc/my.cnf.d

其实配置文件就在这个路径下

  1. 转到这个路径下
[root@iZj6c1drl65inbvxsn0vj5Z etc]# cd my.cnf.d
[root@iZj6c1drl65inbvxsn0vj5Z my.cnf.d]# ls
client.cnf  mysql-default-authentication-plugin.cnf  mysql-server.cnf

发现有三个配置文件

  1. 打开mysql-server.cnf配置文件

    [root@iZj6c1drl65inbvxsn0vj5Z my.cnf.d]# cat mysql-server.cnf
    #
    # This group are read by MySQL server.
    # Use it for options that only the server (but not clients) should see
    #
    # For advice on how to change settings please see
    # http://dev.mysql.com/doc/refman/en/server-configuration-defaults.html

    # 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 mysqld according to the
    # instructions in http://fedoraproject.org/wiki/Systemd

    [mysqld]
    datadir=/var/lib/mysql  #mysql的目录
    socket=/var/lib/mysql/mysql.sock
    log-error=/var/log/mysql/mysqld.log
    pid-file=/run/mysqld/mysqld.pid

    在文件中找到mysql的目录

  2. 进入/var/lib/目录，给mysql整个777权限

    [root@iZj6c1drl65inbvxsn0vj5Z my.cnf.d]# cd /var/lib/
    [root@iZj6c1drl65inbvxsn0vj5Z lib]# chmod 777 mysql
  3. 删掉/var/lib/mysql/目录下所有内容
[root@iZj6c1drl65inbvxsn0vj5Z lib]# rm -rf /var/lib/mysql/*
  1. 启动mysql
    [root@iZj6c1drl65inbvxsn0vj5Z lib]# systemctl status mysqld
    ● mysqld.service - MySQL 8.0 database server
       Loaded: loaded (/usr/lib/systemd/system/mysqld.service; disabled; vendor preset: disabled)
       Active: active (running) since Tue 2022-10-25 15:22:02 CST; 14s ago
      Process: 63886 ExecStopPost=/usr/libexec/mysql-wait-stop (code=exited, status=0/SUCCESS)
      Process: 64082 ExecStartPost=/usr/libexec/mysql-check-upgrade (code=exited, status=0/SUCCESS)
      Process: 63957 ExecStartPre=/usr/libexec/mysql-prepare-db-dir mysqld.service (code=exited, status=0/SU>  Process: 63933 ExecStartPre=/usr/libexec/mysql-check-socket (code=exited, status=0/SUCCESS)
     Main PID: 64038 (mysqld)
       Status: "Server is operational"
        Tasks: 38 (limit: 5036)
       Memory: 405.1M
       CGroup: /system.slice/mysqld.service
               └─64038 /usr/libexec/mysqld --basedir=/usr

方法二

用vim打开mysql-server.cnf时报以下错误导致上述错误

E325: ATTENTION Found a swap file by the name
  • 用” ls -a”找出mysql-server.cnf.swap文件
  • 用”rm -f mysql-server.cnf.swap”删除它
  • 重启MySQL服务