Permissions errors when trying to install mariadb using mariadb-install-db

MySQL & MariaDB MariaDB Server & Utilities
1

I have kubuntu 26.04 and I’m trying to install 3 instances of mariadb using mariadb-install-db. I went through several tutorials, which are all slightly different:

I don’t want to install these instances on my main partition, as the file size could be hundreds of GB and my main drive/partition isn’t big enough. I have a 2TB drive/partition I want to put them on. These tutorials mostly recommend putting the instances in /var/run on the main partition, so I’m not sure if that could be part of the problem.

I created 2 folders on the 2TB drive:

/media/Crucial2TB/mariadb1/
/media/Crucial2TB/mariadb2/

I set both to 755 permissions and the owner and group to “mysql”

When I get to the step where I install/initialize the mariadb folders using mariadb-install-db I keep getting these permissions errors:

raphael@server1:/media/Crucial2TB/mariadb1$ sudo /usr/bin/mariadb-install-db --defaults-file=/etc/mysql/my_multi.cnf --datadir=/media/Crucial2TB/mariadb1/ --verbose --user=mysql
Installing MariaDB/MySQL system tables in '/media/Crucial2TB/mariadb1/' ...
2026-10-01 12:59:01 0 [Warning] Can't create test file '/media/Crucial2TB/mariadb1/linuxserver.lower-test' (Errcode: 13 "Permission denied")
/usr/sbin/mariadbd: Cannot change uid/gid (errno: 1)
2026-10-01 12:59:01 0 [ERROR] Aborting

Installation of system tables failed!  Examine the logs in
/media/Crucial2TB/mariadb1/ for more information.

The problem could be conflicting information in an external
my.cnf files. You can ignore these by doing:

    shell> /usr/bin/mariadb-install-db --defaults-file=~/.my.cnf

You can also try to start the mariadbd daemon with:

    shell> /usr/sbin/mariadbd --skip-grant-tables --general-log &

and use the command line tool /usr/bin/mariadb
to connect to the mysql database and look at the grant tables:

    shell> /usr/bin/mariadb -u root mysql
    MariaDB> show tables;

Try '/usr/sbin/mariadbd --help' if you have problems with paths.  Using
--general-log gives you a log in /media/Crucial2TB/mariadb1/ that may be helpful.

The latest information about mariadb-install-db is available at
https://mariadb.com/kb/en/installing-system-tables-mysql_install_db
You can find the latest source at https://downloads.mariadb.org and
the MariaDB discuss email list at https://lists.mariadb.org/postorius/lists/discuss.lists.mariadb.org/

Please check all of the above before submitting a bug report
at https://mariadb.org/jira

It says

Examine the logs in /media/Crucial2TB/mariadb1/ for more information.

but there are no files in that folder.

This is the config file in /etc/mysql/my_multi.cnf (that I basically copied & pasted from the mariadb website mariadbd-multi | Server | MariaDB Documentation):

[mysqld]
# This file should probably be in your home dir (~/.my.cnf)
       # or /etc/my.cnf
       # Version 2.1 by Jani Tolonen
       [mariadbd-multi]
       mariadbd   = /usr/bin/mariadbd-safe
       mysqladmin = /usr/bin/mysqladmin
       user       = multi_admin
       password   = multipass
       [mariadbd1]
       socket     = /tmp/mysql.sock1
       port       = 3306
       pid-file   = /media/Crucial2TB/mariadb1/server1.pid1
       datadir    = /media/Crucial2TB/mariadb1
       language   = /usr/local/share/mysql/english
       user       = raphael
       tmpdir     = /tmp
       [mariadbd2]
       socket     = /tmp/mysql.sock2
       port       = 3307
       pid-file   = /media/Crucial2TB/mariadb2/server1.pid2
       datadir    = /media/Crucial2TB/mariadb2
       language   = /usr/local/share/mysql/english
       user       = raphael

There are a lot of moving parts here and I don’t know where the issue is. Could it be the “–user” parameter? The user/group/permissions on the folders? The user in the my_multi.cnf file? The user I’m running as? Missing files? Something else?

I also tried editing the /etc/mysql/mariadb.conf.d/50-server-multi.cnf file as mentioned in Ubuntu 22.04 Multi Mariadb install - HackMD but I still got permissions errors.

I would have thought that running mariadb-install-db with sudo would have overridden any permissions issues, so the problem must be somewhere deeper in either Linux/Ubuntu or in the mariadb configs, but I don’t know where to look.

2

In fact, you have been misled. Actually, many codes of mariadbD-Multi of Maria DB point to mysql, so there will be problems when reading files. The simplest method is to manage each instance with an independent my.cnf