So I've gotten to the point where my homelab has moved to a fun way to mess around with tech to starting to replace things like google photos and OneDrive. So as my next project I plan to add resiliency and backup solutions as low-cost/efficiently as I can. I'm thinking that 3 physical machines is a good and safe next step.

I purchased 7 used 4TB SAS drives for my planned storage as I was able to get them for a pretty good deal.

I plan to have a second machine in another state with family that I can setup to run as an off-site backup while the third can run at home or encrypted and put in the cloud (existing OneDrive or b2/S3 glacier) but cloud is obviously a long term cost/subscription.

Ente, a encrypted Google photos replacement, wants three S3 buckets in a production environment, I currently have 1. Until now I've been mirroring photos to Google photos and I have manual exports on my PC/external drives.

So my questions are:

1. What's the most cost effective way to backup proxmox VMs and the trueNAS storage while at the same time being able to move ente from "development" single S3 to the recommended S3 buckets?
2. Hardware is expensive, inefficient and/or loud. What can I get away with that's sub $100 and will be quiet enough to exist in living spaces?
3. Should I add resiliency for networking/DNS/etc on another device or just focus on making these devices just backups?
4. Automation and deployment of additional software. I'm comfortable with docker-compose and see recommendations for kubernetes/Ansible/k3s but I'm not sure if those are worth doing vs just unattended upgrades for security and manual upgrades that I've been doing.
5. Exposing and linking the devices. I have a consumer router w/o layer 3 and ipv6 still scares me with big numbers. So far, I've just exposed wireguard but eventually I need to start exposing ente and other services... For now, and the backups should I create a separate wireguard VPN service as a site-to-site or is there a better option?
6. If I host an S3 bucket at another location, ente needs it to be exposed to the internet as the app communicates directly with the S3 buckets: https://ente.com/help/self-hosting/administration/object-storage?

For hardware: Last I checked arm has some catching up when it comes to proxmox and trueNAS so I'm thinking an old tiny/mini office PC however there's the added complexity of getting SAS drives connected to them and looking decent. If I can source a midsized office PC locally I can probably recreate my existing setup with the off-site backup. I do have a 8GB CM4 thats underutilized since all it's doing is making my ancient printer work wirelessly via cupsd.

My current setup is a single ancient optiplex running proxmox. Within proxmox I have a debian VM running my docker stack and trueNAS with my "large" storage pool

• Dell optiplex 7010
  • Proxmox
    • Debian - docker/portainer - smb mounted TrueNAS
      • Ente Photos w/ S3 object storage via Garage
      • network stack (Adguard, nginx proxy manager, wireguard easy)
      • other services with mounted DB or media stored on trueNAS
    • TrueNAS - 2x4TB HDD via pcie passthrough/HBA card
      • SMB fileshare
      • Garage S3 bucket
    • Windows sever/AD (mostly for learning and managing windows devices)

TL;DR how do I securely/cheaply implement backups and S3 redundancy across multiple locations now that my homelab has important stuff.