When I start SSH server, my Debian automatically start the SFTP server as well - why is it design in such way?
- Linux 5.10.0-14-amd64 Debian 5.10.113-1 (2022-04-29) x86_64 GNU/Linux
- ssh.service - OpenBSD Secure Shell server
Today I realized:
- when I want to handle http requests, I start a web server - Apache(2), Node.js, etc.
- when I want to handle SSH, I start an SSH server
- when I want to handle SFTP... Debian already started SFTP server for me
So I researched, and according to this post 378313/default-sftp-server-in-debian-9-stretch, I found out SFTP is started as "part of (Open)SSH" which makes perfect sense but also feels strange for reasons such as separation of concerns.
Unlike Windows, I have never felt Debian doing something unexpected or extra on my behalf. But today I felt it - after all I said
systemctl restart ssh, not
systemctl restart ssh-and-also-ftp (the latter command is made-up).
As I am new to Unix/Linux and its philosophy, I would appreciate if there are any good explanations for this situation.