Manually Starting a Daemon without SystemD or SysVinit

So I have been revising service management (SystemD) basics, starting, stopping, enabling and disabling etc.

However I found that I can manually start a daemon without using SystemD or SysVinit.

*How is it possible that you can start a daemon and SystemD is not aware (showing as in active) ? - I was under the impression that all daemons statuses can be seen from SystemD.

Although I cant see the daemon as started and running by SystemD, I can see the process is up and running.

Demo:

1) Install vsftpd - yum install vsftpd

2) Manually start daemon - /usr/sbin/vsftpd /etc/vsftpd/vsftpd.conf &

3) Check process - ps -ef | grep vsftpd

4) Check SystemD - systemctl status vsftpd.service

• From a practical perspective, how is this different than accomplishing with SystemD or SysVinit and is there any advantage ?

• Is manually starting a daemon limited to a few applications or is this a generic method ?

Also check this thread out for more elaborate explanation between daemons, services and processes: http://askubuntu.com/questions/192058/what-is-technical-difference-between-daemon-service-and-process

Key Terms:

Daemon - Background Process (Linux)

Service - Provides services (Generic)

Process - Running programs (Generic)

Thanks in advance!