Deleted and Redo, problems solved.
unRaid Version: 6.6.6
HP Microserver n54l
5 HDD 4 + 1 Parity 3TB X 5 Build (No Cache)
I have recently set up a Rsync server on unRaid, it worked like an 1 hour until I moved some files on the destination folder, I don't know why and how this affects the server but now terminal couldn't read rsyncd.conf, it returns cat: /etc/rsyncd.conf: No such file or directory
rsyncd.conf is already placed, the client side couldn't communicate unRaid neither.
The guideline I followed https://forums.unraid.net/…/24282-solved-problem-with-sync…/