To find the error logs of Nginx when using FastCGI with Django, you need to check both the Nginx error logs and the Django application logs. Here's how you can locate these logs:

Nginx Error Logs:
The Nginx error logs are usually located in the / var / log / nginx    / directory. The specific log file you need to check depends on your server configuration. By default, the error log file is often named error.log. You can use the tail command to view the last few lines of the log file in the terminal:

tail -f /var/log/nginx/error.log

This command will show the last few lines of the error log, and the -f flag will keep the command running and display new log entries as they occur.

Django Application Logs:
Django has its own logging mechanism that allows you to customize the logging configuration. By default, Django logs are sent to the console, but you can configure them to be written to a file as well.

In your Django project's settings file (settings.py), you can specify the logging configuration. Look for the LOGGING configuration dictionary, which contains various loggers and handlers. You can add a new handler to write logs to a file:
import logging

LOGGING = {
    'version': 1,
    'handlers': {
        'file': {
            'level': 'ERROR',
            'class': 'logging.FileHandler',
            'filename': '/path/to/your/log/file.log',
        },
    },
    'loggers': {
        'django': {
            'handlers': ['file'],
            'level': 'ERROR',
            'propagate': True,
        },
    },
}

Replace / path / to / your / log / file.log with the actual path where you want to store the logs. With this configuration, Django will write error-level logs to the specified file.
After configuring the logging, you can use a text editor or a terminal command to view the log file:
tail -f /path/to/your/log/file.log

This will show the last few lines of the log file, and the -f flag will keep the command running and display new log entries as they occur.

Remember to adjust the file paths and filenames according to your specific setup and preferences.