SMC-R protocol in Storage Software

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" summary

SMC‑R implements RDMA for TCP sockets on Linux, integrated into SMC tools and the kernel net/smc tree, and is used in IBM Storage Scale on Linux on Z with Rocky adapters and a 100 Gbit switch. Implementation uses AF_SMC sockets or an SMC preload LD_PRELOAD path. With default 128 KB buffers one stream is slower than TCP; increasing to 512 KB yields ~34 Gbit/s and multiple parallel streams reach ~74 Gbit/s. Notes: TCP fallback occurs if peers lack SMC, UDP is unsupported, and kernel patches fix a high‑connection bottleneck not yet merged.

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" chapters (10)

1. 0:00SMC-R in software-defined storage
2. 1:07SMCR enables RDMA connections
3. 2:34Open-source SMCR implementation
4. 3:19Enabling SMC in apps
5. 4:04SMCR tools for monitoring
6. 6:37Software-defined storage overview
7. 8:23SMCR in IBM Storage Scale
8. 9:08SMCR performance bottlenecks
9. 11:14SMCR hardware benchmarks
10. 12:38Summary and Q&A

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