How to disable swap on FriendlyCore

[artofdestroy]

I'm using FriendlyCore xenial 4.14 image with NanoPi neo and I'm trying to disable a swap file by
- sudo swapoff -v /mnt /mnt/512MB.swap
- sudo rm /mnt/512MB.swap
- delete its from /etc/fstab

but every time I reboot NanoPi, this swap file will keep reappearing again.

Anyway to permanently disable a swap file?

[artofdestroy]

"add_swap" service will check and create swap file every time when bootup. After disable swap file, disable "add_swap" service and swap file will not appear anymore.