The history syncers write to the database. A slow DB will cause broken pipes.

Edit the systemd service file: systemctl edit zabbix-server (or zabbix-proxy ). Add the following lines: [Service] LimitNOFILE=65535 Use code with caution. Copied to clipboard Reload and restart: systemctl daemon-reload systemctl restart zabbix-server Use code with caution. Copied to clipboard

tail -n 500 /var/log/zabbix/zabbix_server.log | grep -B 5 -A 5 "broken pipe"

: Ensure the main service is running with ps ax | grep zabbix_server .