MinIO was initially spec'd to what MinIO calls a Toy Setup (3 servers, 3 data disks each) see:

https://github.com/minio/minio/blob/master/docs/distributed/SIZING.md
https://min.io/docs/minio/linux/operations/concepts/architecture.html

While this setup is functional, it has poor availability since losing a single server stops MinIO writes. A small-scale production environment should have one additional data disk to per server for better resiliency, and one additional server per cluster (eqiad vs codfw).

We decided to add one server to each cluster, and one disk to each server.