Fixed interaction of limit_rate and sendfile_max_chunk. It's possible that configured limit_rate will permit more bytes per single operation than sendfile_max_chunk. To protect disk from takeover by a single client it is necessary to apply sendfile_max_chunk as a limit regardless of configured limit_rate. See here for report (in Russian): http://mailman.nginx.org/pipermail/nginx-ru/2010-March/032806.html