December 18, 2025
Super Mario? Nope—Super-Speed SMB
SMB Direct – SMB3 over RDMA – The Linux Kernel Documentation
Linux unlocks warp-speed file sharing; devs debate AI, video editing, and Super Mario vibes
TLDR: Linux adds faster SMB file sharing via RDMA, promising speed boosts if you’re on kernel 5.15+ and use the “rdma” mount option. Comments split between dreamers wanting rapid AI model and video workflows, skeptics questioning soft RDMA gains, and jokers bringing the Super Mario memes—because of course.
Linux’s SMB (shared folders) just got a nitro boost: SMB Direct lets computers sling files using RDMA (a shortcut that skips the usual internet plumbing) for lower lag and high throughput. The doc says if you’re on kernel 5.15+ and flip the right switch, you can mount shares with the “rdma” option and party with KSMBD (the kernel SMB server). But the comments? Pure popcorn. bjackman wonders if folks are literally “using samba to sync model weights” across AI clusters—cue visions of GPUs passing 70 GB blobs like hot potatoes. Meanwhile, geerlingguy’s hyped that Apple’s RDMA over Thunderbolt could make editing video straight off another Mac a reality, not just shuffling LLMs, and asks if Ethernet might join the fun. Skeptics crash the hype train: ohthehugemanate demands real numbers—does soft RDMA (a software emulator) actually beat old-school SMB over IP, or is this just fancy acronym cosplay? And of course, the meme energy arrives: hejira swears SMB3 is Super Mario Bros 3, which is… not wrong on vibes. The drama centers on whether this is a lab-only flex or a real-world speed upgrade. If SMB Direct delivers, expect storage nerds and AI wranglers to go full send. If not, back to TCP and tears. Linux docs SMB Direct
Key Points
- •SMB Direct enables SMB3 over RDMA on Linux for higher throughput and lower latency by bypassing TCP/IP.
- •Linux kernel 5.15 or later is required for SMB Direct support on both client and server sides.
- •RDMA devices can be hardware (InfiniBand, RoCE, iWARP) or software emulators (soft RoCE, soft iWARP), configured via kernel options and iproute2.
- •Server (KSMBD) and client must enable SMB Direct in kernel configs; building installs support into cifs.ko and ksmbd.ko.
- •Clients mount SMB shares with the rdma option and SMB version 3.0+; verification is done via dmesg logs or /proc/mounts.