We are a free/open source project. We are having problems determining why MariaDB 5.5.58 on CentOS 7 is not starting. The start problems happened after we enabled CentOS Software Collections (SCL) and performed a MediaWiki upgrade.

Lack of useful error information is making it hard for us to troubleshoot the issue. I found CentOS’s Issue 9519, /usr/libexec/mariadb-prepare-db-dir fails (and Mariadb won’t start – Failed at step EXEC spawning), but the permissions on / seem OK (see below). We also have the PID file discussed in Red Hat’s Issue 1082018, systemctl start mariadb.service wouldn’t start.

We rent our VM so there is no dmesg or syslog to inspect. It is empty.

If anyone could provide more information on the cause of the failure or additional steps to troubleshoot, then we would be grateful.

MariaDB Conf

# grep -v '#' /etc/my.cnf [mysqld] datadir=/var/lib/mysql socket=/var/lib/mysql/mysql.sock symbolic-links=0  [mysqld_safe] log-error=/var/log/mariadb/mariadb.log pid-file=/var/run/mariadb/mariadb.pid  !includedir /etc/my.cnf.d 

And then:

# echo "" > /var/log/mariadb/mariadb.log 

Other Directories

# ls -al / total 64 dr-xr-xr-x 20 root root 4096 Dec 23 15:46 . dr-xr-xr-x 20 root root 4096 Dec 23 15:46 ..  # ls -al /var/run/mariadb/ total 0 drwxr-xr-x  2 mysql mysql  40 Dec 23 15:46 . drwxr-xr-x 26 root  root  680 Dec 23 18:26 .. 

Data Directory

# ls -al /var/lib/mysql total 35060 drwxr-xr-x  5 mysql mysql     4096 Dec 23 15:45 . drwxr-xr-x 30 root  root      4096 Dec 23 18:52 .. -rw-rw----  1 mysql mysql    16384 Dec 23 15:45 aria_log.00000001 -rw-rw----  1 mysql mysql       52 Dec 23 15:45 aria_log_control -rw-rw----  1 mysql mysql 35651584 Dec 23 15:45 ibdata1 -rw-rw----  1 mysql mysql  5242880 Dec 23 15:45 ib_logfile0 -rw-rw----  1 mysql mysql  5242880 Dec 23 15:31 ib_logfile1 drwx------  2 mysql mysql     4096 Sep 18  2016 mysql drwx------  2 mysql mysql    16384 Dec 23 01:14 my_wiki drwx------  2 mysql mysql     4096 Sep 18  2016 performance_schema 

Attempt to Start

# ls /usr/libexec/mariadb-prepare-db-dir /usr/libexec/mariadb-prepare-db-dir  # 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. 

mariadb.log

# cat /var/log/mariadb/mariadb.log # 

systemctl status

# systemctl -l 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 Sat 2017-12-23 18:29:28 EST; 23s ago   Process: 14537 ExecStartPre=/usr/libexec/mariadb-prepare-db-dir %n (code=exited, status=1/FAILURE)  Dec 23 18:29:28 ftpit systemd[1]: Starting MariaDB database server... Dec 23 18:29:28 ftpit systemd[1]: mariadb.service: control process exited, code=exited status=1 Dec 23 18:29:28 ftpit systemd[1]: Failed to start MariaDB database server. Dec 23 18:29:28 ftpit systemd[1]: Unit mariadb.service entered failed state. Dec 23 18:29:28 ftpit systemd[1]: mariadb.service failed. Oct 27 19:05:23 ftpit systemd[1]: Stopping MariaDB database server... Oct 27 19:05:28 ftpit systemd[1]: Stopped MariaDB database server. Nov 16 12:48:44 ftpit systemd[1]: Stopping MariaDB database server... Nov 16 12:48:54 ftpit systemd[1]: Stopped MariaDB database server. 

journalctl -xe

# journalctl -xe -- Subject: Unit sysinit.target has finished shutting down -- Defined-By: systemd -- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel -- -- Unit sysinit.target has finished shutting down. Nov 16 12:48:57 ftpit systemd[1]: Stopping System Initialization. -- Subject: Unit sysinit.target has begun shutting down -- Defined-By: systemd -- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel -- -- Unit sysinit.target has begun shutting down. Nov 16 12:48:57 ftpit systemd[1]: Stopped target Swap. -- Subject: Unit swap.target has finished shutting down -- Defined-By: systemd -- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel -- -- Unit swap.target has finished shutting down. Nov 16 12:48:57 ftpit systemd[1]: Stopping Swap. -- Subject: Unit swap.target has begun shutting down -- Defined-By: systemd -- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel -- -- Unit swap.target has begun shutting down.