A standalone emulated datacenter for testing the software that runs real datacenters.
dc-twin builds a datacenter out of emulated devices: BMCs, servers, accelerators, DPUs, switches, fabric managers, power shelves, PDUs, CDUs and leak sensors. Every device speaks the protocol its real counterpart speaks, so software installed on top can be tested unmodified. That software includes bare-metal lifecycle managers, fabric managers, fleet-health agents, Kubernetes operators and facility integrations.
The first stack it targets is NVIDIA DSX OS: Infra Controller (NICo), DOCA Platform Framework, NVSentinel, Fleet Intelligence, DSX Exchange, AI Cluster Runtime and KAI Scheduler. The core is vendor-neutral. AMD Instinct, Intel Gaudi, other OEMs and other rack formats are added as packs of device profiles and stack definitions, without changing the engine.
Status: specification (draft 0.2, reviewed), plus a console prototype. The twin itself does not run yet. Start with the spec; the review that produced draft 0.2 and the gaps it still names are in docs/reviews/. The console prototype runs in a browser over an in-memory estate and a simulated stack.
- Testing a datacenter stack before the hardware arrives. Rack ingestion, firmware baselines, tenant hand-over and sanitisation, fault remediation, leak response, power capping.
- Running the failures you can't safely stage on real machines. A leak in rack A07, a switch tray dying mid-allocation, a BMC that stops answering, a GPU that falls off the bus. Each one is injected into the model and shows up consistently on every interface that would reveal it.
- Scale. Thousands of emulated BMCs and Kubernetes nodes on one machine, at reduced fidelity.
- Comparing stacks. The same estate and the same scenarios, run against different vendors' software.
- Seeing and steering it. A web console shows the estate from hall floor to rack elevation to a single GPU. It adds racks and machines, injects faults and technician acts, and follows every request the software under test makes in response (UI).
- Not a performance simulator. No CUDA or ROCm kernels run, no NCCL bandwidth exists, and no packet in the twin says anything about what real silicon would do.
- Not a security proof. Hardware-rooted guarantees, such as DPU-enforced isolation, confidential-computing attestation and real firmware signing, cannot be proven in emulation. The twin says so wherever a result depends on them (fidelity).
- Not a replacement for hardware. Whatever the twin cannot model is listed, and its hardware-in-the-loop mode exists to keep the emulators honest.
- RafaySystems/brave — virtual bare metal for EKS Anywhere on one cloud instance. It inspired the "one big box" deployment model here.
- The mocks NVIDIA ships inside its own components. dc-twin reuses them where they fit (NVIDIA DSX OS stack).
- DMTF's Redfish mockups.
- containerlab.
Apache-2.0. dc-twin never redistributes vendor binaries or images that their licences don't allow to be redistributed. A stack pack says how to obtain them (D13).