opashowmc(8)

💖 opashowmc — the multicast group tea-spiller 💖

okay bestie, so opashowmc is from the IFSFFCLIRG manual crew, and it lives in section 8 of the manual. It's a Linux thing, and here's the whole vibe: it shows you all the Intel(R) Omni-Path Multicast groups that got created for the fabric, plus which Intel(R) Omni-Path Host Fabric Interface (HFI) ports are members of each one of those multicast groups. 🦋

Basically, if you're trying to analyze or debug Intel(R) Omni-Path multicast usage — whether it's some application doing it or a ULP like IPoIB — this is the tool that gives you the receipts. no cap. 💅

✨ Syntax ✨

opashowmc [-v] [-m  mgid] [-t  portsfile] [-p  ports]

🌸 Options 🌸

• --help — gives you the full help text. the whole thing. all of it. 💖
• -v — verbose mode, bestie. It hands back verbose output and shows you the name of each member. 🔥
• -m mgid — narrows it all the way down and shows the membership of the group <mgid> only. just that one group. iconic behavior honestly. 👑
• -t portsfile — picks the file that holds the list of local HFI ports used to access fabric(s) for analysis. The default is the /etc/opa/ports file. 🎀
• -p ports — gives the list of local HFI ports used to access fabric(s) for analysis.

The default is the first active port. Some ground rules so you don't get lost: the first HFI in the system is 1, and the first port on an HFI is 1. The format is hfi:port, so for example:

• 0:0 — first active port in system.
• 0:y — port y within system.
• x:0 — first active port on HFI x.
• x:y — HFI x, port y.

🌈 Examples 🌈

opashowmc

opashowmc -p '1:1 1:2 2:1 2:2' opashowmc -m
0xff12401b80010000:0x00000000ffffffff

🧚 Environment Variables 🧚

these env vars are also used by this command, periodt:

• PORTS — list of ports, used in absence of -t and -p. 💜
• PORTS_FILE — file containing list of ports, used in absence of -t and -p. 🍓

heads up bestie: that -p default is only the first active port, and PORTS / PORTS_FILE only kick in when you haven't passed -t and -p yourself. iykyk 💅

and that's the whole page, mwah 💋 — this gem came to you courtesy of Copyright(C) 2015-2019 Intel Corporation, straight out of the IFSFFCLIRG (Man Page) collection, with opashowmc(8) living its best life in section 8. go read your multicast groups, main character. 🫶✨