fastcgi_max_temp_file_size

When buffering of responses from the FastCGI server is enabled, and the whole response does not fit into the buffers set by the fastcgi_buffer_size and fastcgi_buffers directives, a part of the response can be saved to a temporary file. This directive sets the maximum size of the temporary file. The size of data written to the temporary file at a time is set by the fastcgi_temp_file_write_size directive.

The zero value disables buffering of responses to temporary files.

This restriction does not apply to responses that will be cached or stored on disk.