I have a few decisions I can make on the primary server side which affect the backup options in the backup server, such as: I have tried the software below, each has its own longer blog post on the topic and a short summary is listed here (More may be added in the future as I test more):

Ideally, the backup server will contain mostly lower cost spinning rust, store the complete contents of both the TrueNAS and Proxmox servers, and manage the long term archival and offsite backup. I’d like to back up bulk data stored in TrueNAS, as well as virtual machines and their associated storage stored in Proxmox. Ideally, I can also get a functional offsite backup working, but that might be a future project. It’s definitely an important and often overlooked part of a homelab, or even small business networks. This project included a lot of testing, and will eventually culminate in actually building and setting up a proper backup system. As I outlined in my first blog post on the topic, I want to build a new backup server, and I want to explore the different options I have.

Proxmox backup to backblaze