just some feed for thoughts, only rsync the /var/lib/nethserver, might not be enough since some additional modules put a link in /etc/backup-data.d/ to save their data with the backup module.
[root@NS7DEVAllModules ~]# cat /etc/backup-data.d/*
so if you want a full backup solution, these paths must be saved also.
Therefore a solution like this should be better, supposed that you have a linux client at your home with a port 22 opened in your home firewall
rsync -avzR $(cat /etc/backup-data.d/*) lsd@YourIP:/home/lsd/toto
the -R rsync option save the full path, it will ease your restoration