从Ubuntu 18.04升级到20.04后启动MySQL服务器出现问题

在从Ubuntu 18.04升级到20.04（MySQL 5.7到8）之后，我在启动MySQL时遇到了一个问题。当我试图启动mysql服务包时，它会在“启动mysql社区服务器…”处停止

《华尔街日报》还给了我以下信息

USER@SERVER:~$ journalctl -xe


--
-- The job identifier is 24060.
Aug 19 11:38:17 boris-dev systemd[1]: mysql.service: Main process exited, code=exited, status=1/FAILURE
-- Subject: Unit process exited
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support
--
-- An ExecStart= process belonging to unit mysql.service has exited.
--
-- The process' exit code is 'exited' and its exit status is 1.
Aug 19 11:38:17 boris-dev systemd[1]: mysql.service: Failed with result 'exit-code'.
-- Subject: Unit failed
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support
--
-- The unit mysql.service has entered the 'failed' state with result 'exit-code'.
Aug 19 11:38:17 boris-dev systemd[1]: Failed to start MySQL Community Server.
-- Subject: A start job for unit mysql.service has failed
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support
--
-- A start job for unit mysql.service has finished with a failure.
--
-- The job identifier is 24060 and the job result is failed.
Aug 19 11:38:17 boris-dev systemd[1]: mysql.service: Scheduled restart job, restart counter is at 139.
-- Subject: Automatic restarting of a unit has been scheduled
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support
--
-- Automatic restarting of the unit mysql.service has been scheduled, as the result for
-- the configured Restart= setting for the unit.
Aug 19 11:38:17 boris-dev systemd[1]: Stopped MySQL Community Server.
-- Subject: A stop job for unit mysql.service has finished
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support
--
-- A stop job for unit mysql.service has finished.
--
-- The job identifier is 24126 and the job result is done.
Aug 19 11:38:17 boris-dev systemd[1]: Starting MySQL Community Server...
-- Subject: A start job for unit mysql.service has begun execution
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support
--
-- A start job for unit mysql.service has begun execution.
--
-- The job identifier is 24126.

有一些数据库，保留它们会很好，但不是必需的

你知道最好做什么吗

提前谢谢

---

Bo

您还可以检查

/var/log/mysql/error.log

。要备份mysql数据库，您可以执行

rsync-av/var/lib/mysql//var/lib/mysql-bak/

。然后可以

apt清除mysql服务器

和

apt安装mysql服务器

重新安装。根据我的经验，purge没有删除

/var/lib/mysql/*

，因此我不需要恢复备份。您也可以检查

/var/log/mysql/error.log

。要备份mysql数据库，您可以执行

rsync-av/var/lib/mysql//var/lib/mysql-bak/

。然后可以

apt清除mysql服务器

和

apt安装mysql服务器

重新安装。根据我的经验，purge没有删除

/var/lib/mysql/*

，所以我不需要恢复备份。

USER@SERVER:~$ journalctl -xe


--
-- The job identifier is 24060.
Aug 19 11:38:17 boris-dev systemd[1]: mysql.service: Main process exited, code=exited, status=1/FAILURE
-- Subject: Unit process exited
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support
--
-- An ExecStart= process belonging to unit mysql.service has exited.
--
-- The process' exit code is 'exited' and its exit status is 1.
Aug 19 11:38:17 boris-dev systemd[1]: mysql.service: Failed with result 'exit-code'.
-- Subject: Unit failed
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support
--
-- The unit mysql.service has entered the 'failed' state with result 'exit-code'.
Aug 19 11:38:17 boris-dev systemd[1]: Failed to start MySQL Community Server.
-- Subject: A start job for unit mysql.service has failed
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support
--
-- A start job for unit mysql.service has finished with a failure.
--
-- The job identifier is 24060 and the job result is failed.
Aug 19 11:38:17 boris-dev systemd[1]: mysql.service: Scheduled restart job, restart counter is at 139.
-- Subject: Automatic restarting of a unit has been scheduled
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support
--
-- Automatic restarting of the unit mysql.service has been scheduled, as the result for
-- the configured Restart= setting for the unit.
Aug 19 11:38:17 boris-dev systemd[1]: Stopped MySQL Community Server.
-- Subject: A stop job for unit mysql.service has finished
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support
--
-- A stop job for unit mysql.service has finished.
--
-- The job identifier is 24126 and the job result is done.
Aug 19 11:38:17 boris-dev systemd[1]: Starting MySQL Community Server...
-- Subject: A start job for unit mysql.service has begun execution
-- Defined-By: systemd
-- Support: http://www.ubuntu.com/support
--
-- A start job for unit mysql.service has begun execution.
--
-- The job identifier is 24126.