how long does it take to make a backup?

[Losina]

I bought a Synology NAS to store my backups because my website has about 300GB of data.

I configured the remote backups by sftp but I've been waiting for 5 days and I still don't have the backup, I only get a tmp.xxxx in / backups of my server with vesta

Is there a solution to this? Switch to ftp, compress the backups in some way or I have no choice but to wait