在对 进行一些更改/etc/mysql/mysql.conf.d/mysqld.cnf以增加后max_packet_allowed，MySQL 无法启动。以下是一些日志（tail -30 /var/log/mysql/error.log）
2020-03-02T06:35:28.171879Z 0 [ERROR] [MY-010119] [Server] Aborting
2020-03-02T06:35:28.172491Z 0 [System] [MY-010910] [Server] /usr/sbin/mysqld: Shutdown complete (mysqld 8.0.19-0ubuntu0.19.10.3) (Ubuntu).
2020-03-02T06:35:28.897213Z 0 [System] [MY-010116] [Server] /usr/sbin/mysqld (mysqld 8.0.19-0ubuntu0.19.10.3) starting as process 2584
2020-03-02T06:35:28.936771Z 1 [ERROR] [MY-012576] [InnoDB] Unable to create temporary file; errno: 2
2020-03-02T06:35:28.936890Z 1 [ERROR] [MY-012930] [InnoDB] Plugin initialization aborted with error Generic error.
2020-03-02T06:35:28.936993Z 1 [ERROR] [MY-010334] [Server] Failed to initialize DD Storage Engine
2020-03-02T06:35:28.937251Z 0 [ERROR] [MY-010020] [Server] Data Dictionary initialization failed.
2020-03-02T06:35:28.937371Z 0 [ERROR] [MY-010119] [Server] Aborting
2020-03-02T06:35:28.938002Z 0 [System] [MY-010910] [Server] /usr/sbin/mysqld: Shutdown complete (mysqld 8.0.19-0ubuntu0.19.10.3) (Ubuntu).
2020-03-02T06:35:29.648486Z 0 [System] [MY-010116] [Server] /usr/sbin/mysqld (mysqld 8.0.19-0ubuntu0.19.10.3) starting as process 2594
2020-03-02T06:35:29.678815Z 1 [ERROR] [MY-012576] [InnoDB] Unable to create temporary file; errno: 2
2020-03-02T06:35:29.678904Z 1 [ERROR] [MY-012930] [InnoDB] Plugin initialization aborted with error Generic error.
2020-03-02T06:35:29.678993Z 1 [ERROR] [MY-010334] [Server] Failed to initialize DD Storage Engine
2020-03-02T06:35:29.679249Z 0 [ERROR] [MY-010020] [Server] Data Dictionary initialization failed.
2020-03-02T06:35:29.679369Z 0 [ERROR] [MY-010119] [Server] Aborting
2020-03-02T06:35:29.679973Z 0 [System] [MY-010910] [Server] /usr/sbin/mysqld: Shutdown complete (mysqld 8.0.19-0ubuntu0.19.10.3) (Ubuntu).
2020-03-02T06:35:30.461882Z 0 [System] [MY-010116] [Server] /usr/sbin/mysqld (mysqld 8.0.19-0ubuntu0.19.10.3) starting as process 2604
2020-03-02T06:35:30.511456Z 1 [ERROR] [MY-012576] [InnoDB] Unable to create temporary file; errno: 2
2020-03-02T06:35:30.511544Z 1 [ERROR] [MY-012930] [InnoDB] Plugin initialization aborted with error Generic error.
2020-03-02T06:35:30.511625Z 1 [ERROR] [MY-010334] [Server] Failed to initialize DD Storage Engine
2020-03-02T06:35:30.511892Z 0 [ERROR] [MY-010020] [Server] Data Dictionary initialization failed.
2020-03-02T06:35:30.512013Z 0 [ERROR] [MY-010119] [Server] Aborting
2020-03-02T06:35:30.512646Z 0 [System] [MY-010910] [Server] /usr/sbin/mysqld: Shutdown complete (mysqld 8.0.19-0ubuntu0.19.10.3) (Ubuntu).
2020-03-02T06:35:31.151708Z 0 [System] [MY-010116] [Server] /usr/sbin/mysqld (mysqld 8.0.19-0ubuntu0.19.10.3) starting as process 2614
2020-03-02T06:35:31.182743Z 1 [ERROR] [MY-012576] [InnoDB] Unable to create temporary file; errno: 2
2020-03-02T06:35:31.182831Z 1 [ERROR] [MY-012930] [InnoDB] Plugin initialization aborted with error Generic error.
2020-03-02T06:35:31.182940Z 1 [ERROR] [MY-010334] [Server] Failed to initialize DD Storage Engine
2020-03-02T06:35:31.183182Z 0 [ERROR] [MY-010020] [Server] Data Dictionary initialization failed.
2020-03-02T06:35:31.183314Z 0 [ERROR] [MY-010119] [Server] Aborting
2020-03-02T06:35:31.184000Z 0 [System] [MY-010910] [Server] /usr/sbin/mysqld: Shutdown complete (mysqld 8.0.19-0ubuntu0.19.10.3) (Ubuntu).
有谁知道所显示的错误吗？这是service mysql status
● mysql.service - MySQL Community Server
Loaded: loaded (/lib/systemd/system/mysql.service; enabled; vendor preset: enabled)
Active: failed (Result: exit-code) since Mon 2020-03-02 06:35:31 UTC; 1h 44min ago
Process: 2606 ExecStartPre=/usr/share/mysql/mysql-systemd-start pre (code=exited, status=0/SUCCESS)
Process: 2614 ExecStart=/usr/sbin/mysqld (code=exited, status=1/FAILURE)
Main PID: 2614 (code=exited, status=1/FAILURE)
Status: "Server startup in progress"
Mar 02 06:35:31 localhost systemd[1]: mysql.service: Main process exited, code=exited, status=1/FAILURE
Mar 02 06:35:31 localhost systemd[1]: mysql.service: Failed with result 'exit-code'.
Mar 02 06:35:31 localhost systemd[1]: Failed to start MySQL Community Server.
Mar 02 06:35:31 localhost systemd[1]: mysql.service: Service RestartSec=100ms expired, scheduling restart.
Mar 02 06:35:31 localhost systemd[1]: mysql.service: Scheduled restart job, restart counter is at 5.
Mar 02 06:35:31 localhost systemd[1]: Stopped MySQL Community Server.
Mar 02 06:35:31 localhost systemd[1]: mysql.service: Start request repeated too quickly.
Mar 02 06:35:31 localhost systemd[1]: mysql.service: Failed with result 'exit-code'.
Mar 02 06:35:31 localhost systemd[1]: Failed to start MySQL Community Server.
现在我已经打开了允许评论的最大数据包。