☰

无法启动 MariaDB 数据库服务器

tag-icon • tag-icon linux mysql mariadb
无法启动 MariaDB 数据库服务器

由于/分区只有50G，而我的数据比这个大，而且 里面还有500G的空间/home，所以我把MySQL的所有数据都移到了 里面/home，下面是我的操作步骤（在root账户下）：

  1. 关停 MySQL

    # mysql -u root -p shutdown

  2. 创建data目录。

    # cd /home/ && mkdir data

  3. /var/lib/mysql将目录移动到/home/data

    # mv /var/lib/mysql　/home/data/

  4. 编辑my.cnf和/usr/lib64/mysql/mysql_config

    改成 socket=/var/lib/mysql/mysql.sock​socket=/home/data/mysql/mysql.sock

    datadir=/home/data/mysql仅my.cnf在下[mysqldb]节添加

  5. ln-s

    首先我创建了一个名为的目录mysql。/var/lib/并chown mysql:mysql /var/lib/mysql 创建链接：ln -s /home/data/mysql/mysql.sock /var/lib/mysql/mysql.sock

  6. 更改所有者/home/data/mysql

    chown -R mysql:mysql /home/data/mysql/

  7. 启动 MySQL 服务

    # systemctl start mariadb.service

但是，它启动失败了。

[root@localhost]~# systemctl start mariadb.service                               
Job for mariadb.service failed because the control process exited with error code. See "systemctl status mariadb.service" and "journalctl -xe" for details.

详细信息如下：

[root@localhost]~# systemctl status mariadb.service
● mariadb.service - MariaDB database server
   Loaded: loaded (/usr/lib/systemd/system/mariadb.service; enabled; vendor preset: disabled)
   Active: failed (Result: exit-code) since Thu 2016-04-21 19:51:13 HKT; 39s ago
  Process: 7144 ExecStartPost=/usr/libexec/mariadb-wait-ready $MAINPID (code=exited, status=1/FAILURE)
  Process: 7143 ExecStart=/usr/bin/mysqld_safe --basedir=/usr (code=exited, status=0/SUCCESS)
  Process: 7090 ExecStartPre=/usr/libexec/mariadb-prepare-db-dir %n (code=exited, status=0/SUCCESS)
 Main PID: 7143 (code=exited, status=0/SUCCESS)

Apr 21 19:51:12 localhost.localdomain systemd[1]: Starting MariaDB database server...
Apr 21 19:51:12 localhost.localdomain mysqld_safe[7143]: 160421 19:51:12 mysqld_safe Logging to '/home/data/mysql/localhost.localdomain.err'.
Apr 21 19:51:12 localhost.localdomain mysqld_safe[7143]: 160421 19:51:12 mysqld_safe Starting mysqld daemon with databases from /home/data/mysql
Apr 21 19:51:12 localhost.localdomain mysqld_safe[7143]: 160421 19:51:12 mysqld_safe mysqld from pid file /home/data/mysql/localhost.localdomain.pid ended
Apr 21 19:51:13 localhost.localdomain systemd[1]: mariadb.service: control process exited, code=exited status=1
Apr 21 19:51:13 localhost.localdomain systemd[1]: Failed to start MariaDB database server.
Apr 21 19:51:13 localhost.localdomain systemd[1]: Unit mariadb.service entered failed state.
Apr 21 19:51:13 localhost.localdomain systemd[1]: mariadb.service failed.

[root@localhost]~# journalctl -xe
-- The start-up result is done.
Apr 21 19:50:01 localhost.localdomain systemd[1]: Starting Session 7 of user root.
-- Subject: Unit session-7.scope has begun start-up
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- 
-- Unit session-7.scope has begun starting up.
Apr 21 19:50:01 localhost.localdomain CROND[6971]: (root) CMD (/usr/lib64/sa/sa1 1 1)
Apr 21 19:51:12 localhost.localdomain polkitd[900]: Registered Authentication Agent for unix-process:7084:268964 (system bus name :1.80 [/usr/bin/pkttyagent 
Apr 21 19:51:12 localhost.localdomain systemd[1]: Starting MariaDB database server...
-- Subject: Unit mariadb.service has begun start-up
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- 
-- Unit mariadb.service has begun starting up.
Apr 21 19:51:12 localhost.localdomain mysqld_safe[7143]: 160421 19:51:12 mysqld_safe Logging to '/home/data/mysql/localhost.localdomain.err'.
Apr 21 19:51:12 localhost.localdomain mysqld_safe[7143]: 160421 19:51:12 mysqld_safe Starting mysqld daemon with databases from /home/data/mysql
Apr 21 19:51:12 localhost.localdomain mysqld_safe[7143]: 160421 19:51:12 mysqld_safe mysqld from pid file /home/data/mysql/localhost.localdomain.pid ended
Apr 21 19:51:13 localhost.localdomain systemd[1]: mariadb.service: control process exited, code=exited status=1
Apr 21 19:51:13 localhost.localdomain systemd[1]: Failed to start MariaDB database server.
-- Subject: Unit mariadb.service has failed
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- 
-- Unit mariadb.service has failed.
-- 
-- The result is failed.
Apr 21 19:51:13 localhost.localdomain systemd[1]: Unit mariadb.service entered failed state.
Apr 21 19:51:13 localhost.localdomain systemd[1]: mariadb.service failed.
Apr 21 19:51:13 localhost.localdomain polkitd[900]: Unregistered Authentication Agent for unix-process:7084:268964 (system bus name :1.80, object path /org/f
lines 3132-3161/3161 (END)

我的操作系统是CentOS 7，MySQL是MariaDB。

如何修复？谢谢！

答案1

尝试启动时，请观察 /var/log/messages。您可能会发现 SELinux 妨碍了您：

tail -f /var/log/messages

尝试将 MariaDB 留在预期位置 /var/lib/mysql。选项包括：

1）如果性能很重要：缩小 /home 上的文件系统和分区（或逻辑卷），然后创建一个新分区并将其挂载在 /var/lib/mysql

2）如果性能不太重要：在 /home/mysql.img 上创建一个大文件，并通过 losetup 将该文件用作 /dev/loop0 并挂载在 /var/lib/mysql 上。

3）如果性能确实不重要：对一个大的稀疏文件执行losetup，并将“丢弃”传递给你的ext4文件系统以保持文件稀疏。

答案2

当我尝试将 MariaDB 数据库文件移动到 ISCSI 共享时，我遇到了完全相同的问题。当我的共享已安装并正确格式化后，SELinux 将目录标记为system_u:object_r:unlabeled_t。您可以通过运行以下命令来检查目录的标签...ls -Zd

SELinux 不喜欢意外。因此，要在更改数据目录后运行 MariaDB，您必须重新标记新目录。使用以下命令：semanage fcontext -a -e /var/lib/mysql/ <your new directory>。此命令将旧的 mysql 目录标记映射到新的标记。通过在新标记的目录上运行来重新检查ls -Zd。

最后，使用以下命令将更改传播到整个新修改的目录中：restorecon -R <your new directory>。

所有这些都假设您复制了所有的 mysql 文件而没有进行修改，并且您有原始文件的备份，以便需要恢复。

请参阅以下文章以获取有关此解决方案的参考：

https://www.digitalocean.com/community/tutorials/how-to-change-a-mariadb-data-directory-to-a-new-location-on-centos-7

https://www.unixmen.com/selinux-and-non-default-home-directory-locations/

相关内容