How to Automatically Free Up Storage Space with macOS Sierra http://www.howtogeek.com/272765/how-to-automatically-free-up-storage-space-with-macos-sierra/
The Best New Features in macOS Sierra (and How to Use Them) http://www.howtogeek.com/263543/the-best-new-features-in-macos-sierra/
How To Configure ProFTPd To Use SFTP Instead of FTP https://www.digitalocean.com/community/tutorials/how-to-configure-proftpd-to-use-sftp-instead-of-ftp