I take backup on portable hard-disk, but I wanted online backup/file sync as well.
My requirements were very simple.
Steps I followed to install Mega.nz Linux client on my laptop (OS is Ubuntu 16.04 LTS)
$sudo apt update
$sudo apt install gdebi
$sudo gdebi megasync_4.3.3-2.1_amd64.deb
Search for App called Mega and install it on Ubuntu laptop.