Device offline in mycloud.com - firmware v03.04.01-230

Depends how you want to work; standalone auto-backup controlled by the NAS, or using a host computer.

I use the latter, using FreeFileSync to backup and synchronise selected folders on my PC, and to backup the NAS to external USB HDDs on my PC.

If you want to let the NAS do automatic backups, look into using rsync; for instance:

Or just have a look at some of the things Google suggests:

https://www.google.co.uk/search?q=nas+backup+tools