Ubuntu 20.04 - 已停止 MySQL。现在无法启动（错误 13，权限被拒绝）

Question

在 Ubuntu 20.04 上运行 DigitalOcean LAMP Stack (1GB VPS)，上传媒体文件时，我在 Wordpress 中遇到间歇性的“错误建立数据库连接”错误。 这引发了以下 Apache 错误：

WordPress database error MySQL server has gone away for query...

发生此问题时，MySQL 日志重复打印以下内容，此后没有其他内容：

    2020-12-19T12:14:43.708558Z 0 [System] [MY-013602] [Server] Channel mysql_main configured to support TLS. Encrypted connections are now supported for this channel.
    2020-12-19T12:14:43.992793Z 0 [System] [MY-010931] [Server] /usr/sbin/mysqld: ready for connections. Version: '8.0.22-0ubuntu0.20.04.3'  socket: '/var/run/mysqld/mysqld.sock'  port: 3306  (Ubuntu).
    2020-12-19T12:14:59.498001Z 0 [System] [MY-010116] [Server] /usr/sbin/mysqld (mysqld 8.0.22-0ubuntu0.20.04.3) starting as process 190645
    2020-12-19T12:14:59.512933Z 1 [System] [MY-013576] [InnoDB] InnoDB initialization has started.
    2020-12-19T12:15:00.093514Z 1 [System] [MY-013577] [InnoDB] InnoDB initialization has ended.
    2020-12-19T12:15:00.448326Z 0 [System] [MY-011323] [Server] X Plugin ready for connections. Bind-address: '127.0.0.1' port: 33060, socket: /var/run/mysqld/mysqlx.sock
    2020-12-19T12:15:00.524531Z 0 [System] [MY-010229] [Server] Starting XA crash recovery...
    2020-12-19T12:15:00.543848Z 0 [System] [MY-010232] [Server] XA crash recovery finished.
    2020-12-19T12:15:00.652394Z 0 [Warning] [MY-010068] [Server] CA certificate ca.pem is self signed.

我试过这个修复： WordPress 数据库错误 MySQL 服务器已经离开查询

网站仍然显示错误，所以我想我应该重新启动 MySQL，但它不会重新启动。

随着sudo service MySQL start ，我得到

Job for mysql.service failed because the control process exited with error code. See "systemctl status mysql.service" and "journalctl -xe" for details.

运行第一个命令：

● mysql.service - MySQL Community Server
 Loaded: loaded (/lib/systemd/system/mysql.service; enabled; vendor preset: enabled)
 Active: failed (Result: exit-code) since Sat 2020-12-19 12:45:50 UTC; 1min 3s ago
Process: 192068 ExecStartPre=/usr/share/mysql/mysql-systemd-start pre (code=exited, status=0/SUCCESS)
Process: 192076 ExecStart=/usr/sbin/mysqld (code=exited, status=1/FAILURE)
Main PID: 192076 (code=exited, status=1/FAILURE)
 Status: "Server startup in progress"
  Error: 13 (Permission denied)

运行第二个命令

 Hint: You are currently not seeing messages from other users and the system.
  Users in groups 'adm', 'systemd-journal' can see all messages.
  Pass -q to turn off this notice.
 -- Defined-By: systems
 -- Support: http://www.ubuntu.com/support
 --
 -- A start job for unit UNIT has finished successfully.
 --
 -- The job identifier is 8.
 Dec 19 12:13:48 server systemd[189372]: Listening on REST API socket for snapd user session agent.
 -- Subject: A start job for unit UNIT has finished successfully
 -- Defined-By: systems
 -- Support: http://www.ubuntu.com/support
 --
 -- A start job for unit UNIT has finished successfully.
 --
 -- The job identifier is 11.
 Dec 19 12:13:48 server systemd[189372]: Listening on D-Bus User Message Bus Socket.
 -- Subject: A start job for unit UNIT has finished successfully
 -- Defined-By: systems
 -- Support: http://www.ubuntu.com/support
 --
 -- A start job for unit UNIT has finished successfully.
 --
 -- The job identifier is 9.
 Dec 19 12:13:48 server systemd[189372]: Reached target Sockets.
 -- Subject: A start job for unit UNIT has finished successfully
 -- Defined-By: systems
 -- Support: http://www.ubuntu.com/support
 --
 -- A start job for unit UNIT has finished successfully.
 --
 -- The job identifier is 5.
 Dec 19 12:13:48 server systemd[189372]: Reached target Basic System.
 -- Subject: A start job for unit UNIT has finished successfully
 -- Defined-By: systems
 -- Support: http://www.ubuntu.com/support
 --
 -- A start job for unit UNIT has finished successfully.
 --
 -- The job identifier is 2.
 Dec 19 12:13:48 server systemd[189372]: Reached target Main User Target.
 -- Subject: A start job for unit UNIT has finished successfully
 -- Defined-By: systems
 -- Support: http://www.ubuntu.com/support
 --
 -- A start job for unit UNIT has finished successfully.
 --
 -- The job identifier is 1.
 Dec 19 12:13:48 server systemd[189372]: Startup finished in 168ms.
 -- Subject: User manager start-up is now complete
 -- Defined-By: systems
 -- Support: http://www.ubuntu.com/support
 --
 -- The user manager instance for user 1000 has been started. All services queued
 -- for starting have been started. Note that other services might still be starting
 -- up or be started at any later time.
 --
 -- Startup of the manager took 168965 microseconds.
 Dec 19 12:15:07 server sudo[190726]: pam_unix(sudo:auth): Couldn't open /etc/securetty: No such file or directory
 Dec 19 12:15:09 server sudo[190726]: pam_unix(sudo:auth): Couldn't open /etc/securetty: No such file or directory
 Dec 19 12:30:17 server sudo[191518]: pam_unix(sudo:auth): Couldn't open /etc/securetty: No such file or directory
 Dec 19 12:30:19 server sudo[191518]: pam_unix(sudo:auth): Couldn't open /etc/securetty: No such file or directory
 Dec 19 12:32:25 server sudo[191686]: pam_unix(sudo:auth): Couldn't open /etc/securetty: No such file or directory
 Dec 19 12:32:27 server sudo[191686]: pam_unix(sudo:auth): Couldn't open /etc/securetty: No such file or directory

第一个错误让我想到了这个： https://askubuntu.com/questions/1228827/mysql-error-13-permission-denied

然而 MySQL 已经拥有 /var/lib/mysql。 /usr/sbin/mysqld 的所有者是 root。 这与 MySQL 工作正常的另一台服务器相同。 我真的应该改变这个吗？

Answer 1

问题是我已经让我的用户拥有 /var/log/mysql 来读取文件。 sudo chown mysql:mysql -R /var/log/mysql允许我启动 mysql。

Answer 2

简单运行更新命令
apt-get 更新
apt-get 升级
它会自动更新 mysql 所需的权限。
它解决了我的问题

Answer 3

Had the same issue system status mysql Main PID: 178577 (code=exited, status=1/FAILURE) Status: "Server startup in progress" Error: 13 (Permission denied) solution for me chown mysql:mysql -R /var/lib/mysql/ /var/log/mysql/启动正常

Answer 4

如果您手动删除binlog文件，也可能会发生这种情况。 检查/var/log/mysql/error.log以及问题是否与最后一个 binlog 文件有关。 在这种情况下，清除文件/var/lib/mysql/binlog.index的内容然后重新启动 mysql 对我有帮助。

Answer 5

我也遇到了同样的问题。 我将 mysql 数据目录从/var/lib/mysql移动到/media/anand/databank/mysql 。 我将所有读写权限授予所有用户/组，但 mysql 服务器无法重新启动， Error: 13 (Permission denied) 。 在反复阅读这个和其他线程之后，我可以弄清楚文件夹anand没有授予其他人（包括用户 mysql）的访问权限。 因此，即使用户（在我的例子中是 mysql）具有对mysql文件夹的完全访问权限，但在该用户获得访问anand文件夹的权限之前，该用户不会访问mysql文件夹。 有一次，我在 foledr anand上授予 mysql 用户只读权限，mysql 服务器启动无误。

简而言之，如果您授予用户对某个文件夹的权限。 请检查此类用户是否至少对所有父文件夹具有只读/访问文件权限