I have about 8TB of storage that is currently only replicated through a raid array. I occasionally sync that to another USB drive and leave that in a fireproof safe (same location).
I'd really like to do an offsite backup, but I only have 10Mbps upload. We are literally talking months to do a full backup.
How do others handle situations like this?
I don't know whether it's important to do a full backup for performance, but you'd need to do that if you wanted to remove old backups. It looks like the term for a full backup that reuses already pushed-over data is a "synthetic full" backup, and duplicity can't do those – when it does a full, it pushes all the data over again.
I have never used it, but Borg Backup does appear to support this, if you wanted an alternate that can do this.
EDIT: However, Borg requires code that runs on the remote end, which may not be acceptable for some; you can't just aim it at a fileserver. duplicity can do this.
I have also never used it, but duplicati looks to my quick glance to be able to work without code running on the remote end and also to do synthetic full backups.