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| wiki:ai:gaudi-cluster-setup [2026/07/21 17:41] – swilson | wiki:ai:gaudi-cluster-setup [2026/07/21 17:45] (current) – swilson | ||
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| * **Compute nodes:** bare-metal servers, 8 Gaudi accelerators each. | * **Compute nodes:** bare-metal servers, 8 Gaudi accelerators each. | ||
| - | * **Node-to-node networking: | + | * **Node-to-node networking: |
| - | * **Management network, storage, monitoring stack:** identical to our NVIDIA setup — same tools, same team. | + | * **Management network, storage, monitoring stack:** identical to our NVIDIA setup, same tools, same team. |
| * **Job scheduling: | * **Job scheduling: | ||
| + | |||
| + | ===== Architecture Diagram ===== | ||
| + | |||
| + | < | ||
| + | +-------------------------+ | ||
| + | | | ||
| + | | (BCM, Prometheus, | ||
| + | | | ||
| + | +------------+------------+ | ||
| + | | | ||
| + | | ||
| + | | | ||
| + | +----------------------------+----------------------------+ | ||
| + | | | | | ||
| + | +-----v-----+ | ||
| + | | Gaudi | ||
| + | | Node 1 | | ||
| + | | 8x Gaudi | | ||
| + | | cards | ||
| + | +-----+-----+ | ||
| + | | | | | ||
| + | +----------------------------+----------------------------+ | ||
| + | | | ||
| + | | ||
| + | mesh for small clusters, leaf-spine | ||
| + | | ||
| + | | | ||
| + | +------------v------------+ | ||
| + | | | ||
| + | | | ||
| + | +----------------------------+ | ||
| + | </ | ||
| ===== Networking Topology ===== | ===== Networking Topology ===== | ||
| - | * **Gaudi 2:** 24 RoCEv2 ports per card — 21 used for scale-out (node-to-node) and 3 for scale-up (intra-node all-to-all mesh between the 8 accelerators). | + | * **Gaudi 2:** 24 RoCEv2 ports per card, 21 used for scale-out (node-to-node) and 3 for scale-up (intra-node all-to-all mesh between the 8 accelerators). |
| * **Gaudi 3:** same port layout, doubled per-port bandwidth (roughly 2x Gaudi 2 fabric throughput). | * **Gaudi 3:** same port layout, doubled per-port bandwidth (roughly 2x Gaudi 2 fabric throughput). | ||
| * **Small clusters** (typically up to 32 nodes / 256 cards) can often wire nodes directly card-to-card in a mesh without external switches, cutting hardware cost. | * **Small clusters** (typically up to 32 nodes / 256 cards) can often wire nodes directly card-to-card in a mesh without external switches, cutting hardware cost. | ||
| - | * **Larger clusters** need a leaf-spine Ethernet fabric with RoCEv2-capable switches (e.g. Arista, NVIDIA Spectrum, or similar 400GbE-class gear). Standard Ethernet, not a proprietary interconnect | + | * **Larger clusters** need a leaf-spine Ethernet fabric with RoCEv2-capable switches (e.g. Arista, NVIDIA Spectrum, or similar 400GbE-class gear). Standard Ethernet, not a proprietary interconnect; this is the main operational difference from an InfiniBand-based NVIDIA fabric. |
| - | * Lossless Ethernet configuration (PFC/ECN) on the switches matters for RoCEv2 performance | + | * Lossless Ethernet configuration (PFC/ECN) on the switches matters for RoCEv2 performance; treat this the same way you'd tune an NVIDIA RoCE fabric, since there' |
| ===== Host & Storage Considerations ===== | ===== Host & Storage Considerations ===== | ||
| - | * **Host CPU/ | + | * **Host CPU/ |
| * **Local NVMe:** recommended per node for checkpoint/ | * **Local NVMe:** recommended per node for checkpoint/ | ||
| - | * **Shared storage:** reuse the existing parallel filesystem (Lustre/ | + | * **Shared storage:** reuse the existing parallel filesystem (Lustre/ |
| ===== Job Scheduling Notes ===== | ===== Job Scheduling Notes ===== | ||
| * Tag Gaudi nodes with a distinct partition/ | * Tag Gaudi nodes with a distinct partition/ | ||
| - | * HCCL (Habana Collective Communications Library) is the NCCL equivalent | + | * HCCL (Habana Collective Communications Library) is the NCCL equivalent; set `HCCL_*` env vars analogous to how `NCCL_*` vars are tuned today, particularly around scale-out topology hints if nodes aren't in a simple mesh. |
| * Health checks: monitor for downed RoCE links and card resets the same way GPU health checks are wired into scheduler drain logic today. | * Health checks: monitor for downed RoCE links and card resets the same way GPU health checks are wired into scheduler drain logic today. | ||