meta/architecture-docs/2024-12-09 storage.md

Storage architecture with Garage

Attendees: Koen, Valentin, Nicolas

• (some historical/technical background discussion on object storage and file systems)
• Koen: 1.5 y ago looked into available FOSS solutions, only minio and Garage
  • Garage was NGI-funded and located in France and responsive
    • Targeted at self-hosting, minimal hardware requirements
  • Ideally would have used a W3C standard protocol, but "S3-compatible" is the closest thing
• Should have a few big, replicated, well-monitored storage clusters instead of many small ones
  • Currently have 3x4Ux32drive storage boxes; would replicate them over 3 locations
• (discussion of ZFS performance characteristics)
• Koen presented a storage architecture based on ZFS
  • Main feature (not clear on the details) is to add a NVMe-based primary write target to Garage
    • e.g. 45TB NVMe + (2x?) 560 TB (1PB raw) HDD
    • According to independent reviews[citation needed] Garage handles this sort of setup better than minio
• Requirement estimates:
  • mastodon.nl has 50k users, 5k active users, 200GB database (ever-growing, launched Nov 2022), 1.5 TB of files
    • Hot data is <~5 days old, most of the rest is never looked up
  • Most of the usage profiles intel will have to come from our university partners
  • Will scale the physical storage to the actual write capacity requirements at the spindle layer (add more vdevs as needed)
• Additional object storage replication can be configured at the S3 (Garage) layer by setting another target at a different provider
  • We expect this to happen rarely; replication will likely take a lot of performance out of the application
  • By default we already have 3-way replication internally (i.e. 3 RAIDZ2 machines per Garage instance)
• There are already three sites in NL to rack the hardware
  • This is why we need to connect NetherLight so NORDUnet universities have a low-latency connection
• Koen: Ideally at the end of next year you'd have three sites set up with machines to run Proxmox on and the storage machines, and run a NixOS ISO to set everything up and then control it via NixPanel
• Nicolas: We should talk to Garage developers, because they run it on NixOS but not sure how exactly
  • Koen: Ideally before FOSDEM 2025
• Valentin: Need reference documentation for the storage architecture discussed (so we can point to something when making implementation decisions), and a slide deck to tell the story of how it came into being (as a sales device for the project), and eventually derive business plans for hosting providers and operators from that

Hand-drawn sketches posted to the internal private repo