Overview
The Login Failure Daemon (LFD) may terminate unexpectedly when monitoring a high volume of domains in Plesk due to exceeding the server's open file descriptor limit. Increasing this limit prevents service interruptions and ensures stable firewall operations.
Prerequisites
- Root or sudo access to the server
Procedure
Follow these steps to increase the open file limit for the LFD service:
- Create a systemd override configuration for the login failure daemon by executing the following command:
systemctl edit lfd.service - In the text editor that opens, add the following lines to configure the LimitNOFILE parameter under the [Service] section:
[Service] LimitNOFILE=65536 - Save and close the editor.
- Apply the updated configuration by reloading the systemd manager:
systemctl daemon-reload - Restart the LFD service to apply the changes:
systemctl restart lfd.service
Troubleshooting
If the service fails to start after applying these changes, verify that the override file was saved correctly and check the current status of the lfd.service unit:
systemctl status lfd.service