Thanks for the response. The reason why I want to implement this is because I have dedicated server and thanks to nginx everything is work perfectly so I don't need to check server everyday. I don't want to locate logs on ssd main (hardrive /var/log/nginx/) which is obviously smaller hard disk than my external sata hdd (/externalhdd/log/nginx/). I am afraid if something happens to external hard drive time to time, I still want my website to operate after restart because every week server restart by itself due to some limitation of some programs. I guess it will give me error message nginx couldn't found access.log if external hard disk dies prior to restart nginx. I want to avoid this problem.

thanks.