Longhorn#
Longhorn provides distributed block storage with replicated volumes and snapshots.
v1 data engine#
The cluster runs with the v1 (iSCSI-based) data engine. The v2 engine (SPDK) is not in use.
Resource tuning#
On the DGX Spark nodes (20 cores each), the default Longhorn instance manager CPU reservation was too aggressive. The setting guaranteedInstanceManagerCPU is tuned to 5 to reduce per-instance-manager reservation.
Consumers#
Stateful workloads using Longhorn PVCs:
| Workload | Storage per replica |
|---|---|
| Kafka (Strimzi, 3 brokers) | 50 GiB |
| NATS (3 nodes) | 20 GiB |
| RabbitMQ (3 replicas) | 20 GiB |
| Grafana | varies |
Web UI#
The Longhorn dashboard is available at longhorn.wcloud.sh for volume management, snapshot creation, and monitoring.