数据库连接异常：MariaDB无法启动

执行命令sudo /opt/bitnami/ctlscript.sh restart时，Apache正常启动，但MariaDB启动失败。journalctl -xe日志如下：

Aug 16 16:29:54 ip-172-26-6-254 bitnami[7264]: ## 2022-08-16 16:29:54+00:00 ## INFO ## Starting services...
Aug 16 16:29:55 ip-172-26-6-254 bitnami[7264]: 2022-08-16T16:29:55.550Z - info: Saving configuration info to disk
Aug 16 16:29:55 ip-172-26-6-254 bitnami[7264]: 2022-08-16T16:29:55.915Z - info: Performing service start operation for php
Aug 16 16:29:56 ip-172-26-6-254 bitnami[7264]: php 16:29:56.22 INFO  ==> php-fpm is already running
Aug 16 16:29:56 ip-172-26-6-254 bitnami[7264]: 2022-08-16T16:29:56.225Z - info: Performing service start operation for apache
Aug 16 16:29:56 ip-172-26-6-254 bitnami[7264]: apache 16:29:56.50 INFO  ==> apache is already running
Aug 16 16:29:56 ip-172-26-6-254 bitnami[7264]: 2022-08-16T16:29:56.503Z - info: Skipping service start operation for varnish
Aug 16 16:29:56 ip-172-26-6-254 bitnami[7264]: 2022-08-16T16:29:56.503Z - info: Performing service start operation for mariadb
Aug 16 16:30:56 ip-172-26-6-254 bitnami[7264]: mariadb 16:30:56.82 ERROR ==> mariadb did not start
Aug 16 16:30:56 ip-172-26-6-254 bitnami[7264]: 2022-08-16T16:30:56.831Z - error: Unable to perform start operation Export start for mariadb failed with exit code 1
Aug 16 16:30:56 ip-172-26-6-254 bitnami[7264]: ## 2022-08-16 16:30:56+00:00 ## INFO ## Running /opt/bitnami/var/init/post-start/010_bitnami_agent_extra...
Aug 16 16:30:56 ip-172-26-6-254 bitnami[7264]: ## 2022-08-16 16:30:56+00:00 ## INFO ## Running /opt/bitnami/var/init/post-start/020_bitnami_agent...
Aug 16 16:30:56 ip-172-26-6-254 bitnami[7264]: ## 2022-08-16 16:30:56+00:00 ## INFO ## Running /opt/bitnami/var/init/post-start/030_update_welcome_file...
Aug 16 16:30:56 ip-172-26-6-254 bitnami[7264]: ## 2022-08-16 16:30:56+00:00 ## INFO ## Running /opt/bitnami/var/init/post-start/040_bitnami_credentials_file...
Aug 16 16:30:56 ip-172-26-6-254 bitnami[7264]: ## 2022-08-16 16:30:56+00:00 ## INFO ## Running /opt/bitnami/var/init/post-start/050_clean_metadata...
Aug 16 16:30:56 ip-172-26-6-254 sudo[7255]: pam_unix(sudo:session): session closed for user root
Aug 16 16:30:56 ip-172-26-6-254 systemd[1]: bitnami.service: Control process exited, code=exited, status=1/FAILURE
-- Subject: Unit process exited
-- Defined-By: systemd
-- Support: https://www.debian.org/support
-- 
-- An ExecStart= process belonging to unit bitnami.service has exited.
-- 
-- The process' exit code is 'exited' and its exit status is 1.

单独执行sudo /opt/bitnami/ctlscript.sh restart mariadb时，命令卡顿约1分钟后返回错误：

Failed to restart mariadb: Failed to restart mariadb

1. 查看MariaDB详细日志 #

Bitnami环境下MariaDB的日志文件位于/opt/bitnami/mariadb/logs/mysqld.log，执行以下命令获取最新错误信息：

tail -n 50 /opt/bitnami/mariadb/logs/mysqld.log

日志会明确显示启动失败的具体原因，比如权限问题、磁盘空间不足、配置语法错误或数据库文件损坏。

2. 清理残留进程 #

检查是否有未正常退出的MariaDB进程占用端口：

ps aux | grep mariadb

如果存在残留进程，强制杀死后再尝试启动：

sudo kill -9 <进程ID>
sudo /opt/bitnami/ctlscript.sh start mariadb

3. 修复文件权限 #

确保MariaDB的数据目录和日志目录归bitnami用户所有：

sudo chown -R bitnami:bitnami /opt/bitnami/mariadb/data
sudo chown -R bitnami:bitnami /opt/bitnami/mariadb/logs

4. 检查磁盘空间 #

磁盘满会导致MariaDB无法写入日志或数据，执行以下命令查看磁盘使用率：

df -h

若磁盘接近饱和，清理无用文件后再启动服务。

5. 验证配置文件语法 #

检查MariaDB配置文件是否存在语法错误：

/opt/bitnami/mariadb/bin/mysqld --defaults-file=/opt/bitnami/mariadb/conf/my.cnf --validate-config

根据提示修正配置错误后重启服务。

6. 修复数据库损坏 #

如果日志提示数据库文件损坏，执行以下命令修复：

sudo /opt/bitnami/mariadb/bin/mysqlcheck -u root -p --all-databases --repair

输入MariaDB root密码后等待修复完成，再启动服务。

内容的提问来源于stack exchange，提问作者acs254