I want to use it only for synology server backup. Is it possible?
Have you looked at Synology’s Cloud Station package to see if you can configure it to backup the Synology to another local network NAS?
On the My Cloud one can access the My Cloud using SSH to issue the rsync command. Use the forum search feature, if you haven’t done so already, and search for rsync. There are several past discussions on using rsync to copy data from the My Cloud to another location.
Edit to add: See the Synology Backup Packages as there are several backup packages. Perhaps one of them will backup the Synology to another NAS.
https://www.synology.com/en-us/dsm/packages?group=Backup&search=
Yes, the synology server is doing a backup on another Synology NAS server.
I found some advice how to run rsync on mycloud but it doesn’t work for me. After restart all settings will be reset. In order to keep it permanently you need to upload some crack files? I’m not going to play this game but I’ll sell this ■■■■■■ mycloud and buy a second synology for backup.
Thank you 
