ulimit

editing /etc/security/limits.conf might not result in anything you’re looking for. Go ahead:

create the folder /etc/systemd/system.conf.d/ and edit the following file:

sudo mkdir -p /etc/systemd/system.conf.d/
sudo vi /etc/systemd/system.conf.d/limits.conf

put this in here, you might want to adopt the numbers

[Manager]
DefaultLimitNOFILE=1048576:2097152
DefaultLimitNPROC=262144:524288

you need to restart the systems afterwards.