Convert MariaDB Settings with mariadb-service-convert

Moving MariaDB from old mysqld_safe settings to systemd gets a lot less scary once mariadb-service-convert does the translation for you. You will generate a systemd drop-in from the settings currently visible to the tool, review the result, install it without touching the packaged unit, and verify the service. Allow about fifteen minutes, plus a restart window if MariaDB is already serving applications.

The examples use MariaDB 10.11.14 from the installed mariadb-server package. The command's manual page is dated 15 May 2020, so the generated text and the installed unit on your own host are the real authority for this run. You need shell access and, for installation, an account allowed to use sudo.

1. Check the installed command

First confirm which binary and package version you are about to use. These are ordinary read-only commands:

$ command -v mariadb-service-convert
/usr/bin/mariadb-service-convert
$ mariadb --version
mariadb  Ver 15.1 Distrib 10.11.14-MariaDB, for debian-linux-gnu (x86_64) using  EditLine wrapper
$ dpkg-query -W -f='${Package} ${Version}\n' mariadb-server
mariadb-server 1:10.11.14-0ubuntu0.24.04.1

2. Generate a temporary file

The utility takes no documented options. It writes a service configuration to standard output, so redirect that to a temporary file first rather than writing straight into /etc:

$ work_dir=$(mktemp -d /tmp/mariadb-service-convert.XXXXXX)
$ mariadb-service-convert > "$work_dir/migrated-from-my.cnf-settings.conf"
$ printf 'exit status: %s\n' "$?"
exit status: 0
$ sed -n '1,120p' "$work_dir/migrated-from-my.cnf-settings.conf"
# converted using /usr/bin/mariadb-service-convert
#

[Service]

StandardOutput=syslog
StandardError=syslog
SyslogFacility=daemon
SyslogLevel=err
SyslogIdentifier=mysqld

Your own output can list different settings. The important shape is a systemd [Service] section preceded by a conversion comment. A successful exit status means the generator ran; it does not mean every setting belongs in production.

3. Review the generated settings

Read the whole temporary file before installing anything. Compare each setting against the current MariaDB service and against the reason you are migrating off mysqld_safe settings in the first place:

$ sed -n '1,240p' "$work_dir/migrated-from-my.cnf-settings.conf"
$ systemctl cat mariadb.service
$ systemctl show mariadb.service --property=DropInPaths --no-pager

The generated file is a drop-in, not a full replacement for mariadb.service. In particular, do not assume it carries ExecStart, user and group settings, limits, or hardening from the packaged unit. Leave the package's unit file untouched so upgrades can still replace it safely.

4. Install the reviewed drop-in

Only this step changes system state, and it needs elevated privileges. The manual recommends a path under /etc/systemd/system/mariadb.service.d/. Create the directory and copy the reviewed file with a fixed mode:

$ sudo install -d -m 0755 /etc/systemd/system/mariadb.service.d
$ sudo install -o root -g root -m 0644 \
    "$work_dir/migrated-from-my.cnf-settings.conf" \
    /etc/systemd/system/mariadb.service.d/migrated-from-my.cnf-settings.conf

Check what actually got installed before asking systemd to reread unit files:

$ sudo sed -n '1,240p' /etc/systemd/system/mariadb.service.d/migrated-from-my.cnf-settings.conf
$ systemctl show mariadb.service --property=DropInPaths --no-pager
DropInPaths=/etc/systemd/system/mariadb.service.d/migrated-from-my.cnf-settings.conf

If the destination already exists, install replaces it. Preserve the old version first if you might want a quick rollback:

$ sudo cp --preserve=all \
    /etc/systemd/system/mariadb.service.d/migrated-from-my.cnf-settings.conf \
    /etc/systemd/system/mariadb.service.d/migrated-from-my.cnf-settings.conf.bak

5. Reload and validate without restarting

Ask systemd to reread unit files, then inspect the merged result. This step does not restart MariaDB:

$ sudo systemctl daemon-reload
$ systemctl cat mariadb.service
$ systemd-analyze verify mariadb.service

6. Apply the change during a maintenance window

A reload only updates systemd's view of the configuration. To make a service property take effect for a running MariaDB process, schedule a restart and check the result:

$ sudo systemctl restart mariadb.service
$ systemctl is-active mariadb.service
active
$ systemctl status mariadb.service --no-pager

7. Undo the drop-in if needed

To return to the packaged unit, remove only the file created for this migration, then reload systemd. Removing a drop-in changes state and needs sudo:

$ sudo rm /etc/systemd/system/mariadb.service.d/migrated-from-my.cnf-settings.conf
$ sudo systemctl daemon-reload
$ systemctl show mariadb.service --property=DropInPaths --no-pager