MySQL out of resources on Fedora 20+

If you got this error:

when opening file '/var/tmp/#sql....MAI' (Errcode: 24)

Here is the fix:

In my experience with Fedora 20+, you don’t need to set ulimit, nor /etc/security/limits.conf, nor /etc/my.cnf.

Just set it in systemd.

mkdir /etc/systemd/system/mariadb.service.d/
vim /etc/systemd/system/mariadb.service.d/limits.conf

and add:

[Service]
LimitNOFILE=10000

Run command:

systemctl daemon-reload
systemctl restart mariadb

Verify the value with SQL:

SHOW VARIABLES LIKE 'open%';

This fix is found from /usr/lib/systemd/system/mariadb.service.