The thing is that every Samba shared folder created has only 20 GB storage capacity. So far 3 users have been successfully created. I am planning to create as much Unix/Samba users as workstations and servers in LAN in a way that for every machine there will be a unique Samba shared folder for backup in the NAS.
I set up a WD USB external drive as a NAS on Ubuntu Server 18.04 to use it as file backup server, and I also successfully set Samba server. UUID=usb_drive_id /mnt/usb_drive1 exfat defaults,usrquota,_netdev 0 0
