lst(8)

✨ lst(8) — the Lustre self-test situation ✨

okay bestie, buckle up 💖 this one lives in the configuration utilities corner of your manual, and it's genuinely iconic. it's giving "I test your network so you don't have to cry about it."

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🌸 NAME 🌸

lst — start the Lustre LNET Self-test

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🎀 SYNOPSIS 🎀

lst
lst --list-commands

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🦋 DESCRIPTION 🦋

so LNET self-test is the whole vibe where site admins go "hey, is Lustre Networking (LNET) actually installed and configured correctly, or am I delulu?" 💅 It confirms that LNET — plus the network software and hardware underneath it — are performing according to expectations. No cap.

Every LNET self-test run happens in the context of a session. and like, a node can only be associated with one session at a time, so that session gets exclusive use of the nodes it's running on. one node, one situationship. periodt. ✨

A session gets created, controlled and monitored from a single node, and that node is called the self-test console. main character energy fr.

Any node can be the self-test console, lowkey anyone can do it. Nodes get named and allocated to a self-test session in groups, which is the slay move because it means you can reference every node in a group with just one single name. group chat, basically. 🫶

Test configurations get built by describing and running test batches. A test batch is just a named collection of tests, and each test is composed of a bunch of individual point-to-point tests running in parallel. Those individual point-to-point tests get instantiated according to the test type, source group, target group and distribution you specified when you added the test to the batch. iykyk.

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✨ OPTIONS ✨

• --list-commands — prints out a list of all the commands the lst utility supports. your menu of options, bestie 📋

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💖 MODULES 💖

To run LNET self-test, you need to load these modules: libcfs, lnet, lnet_selftest, and any one of the klnds (i.e., ksocklnd, ko2iblnd...). To load all the necessary modules in one go, run modprobe lnet_selftest — it recursively loads everything lnet_selftest depends on. one command and done, we love to see it. 😌

There are two node types for LNET self-test: the console node and test nodes. Both types require all those previously-specified modules to be loaded. (The userspace test node does not require these modules — she's built different. 🙈)

A console user can invite a test node to join the test session by running lst add_group NID. cute, an invitation 💌

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👑 UTILITIES 👑

lst is the user interface for the self-test console, and it runs on the console node. It hands you a whole list of commands to control the entire test system — stuff like create session, create test groups, etc. it's the entire control room, bestie.

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🌈 EXAMPLE SCRIPT 🌈

okay so here's a sample LNET self-test script. It simulates the traffic pattern of a set of Lustre servers on a TCP network, accessed by Lustre clients on an IB network (connected via LNET routers), with half the clients reading and half the clients writing. it's giving balanced. it's giving symmetrical. 💅

#!/usr/bin/bash
export LST_SESSION=$$
lst new_session read/write
lst add_group servers 192.168.10.[8,10,12-16]@tcp
lst add_group readers 192.168.1.[1-253/2]@o2ib
lst add_group writers 192.168.1.[2-254/2]@o2ib
lst add_batch bulk_rw
lst add_test --batch bulk_rw --from readers --to servers     brw read check=simple size=1M
lst add_test --batch bulk_rw --from writers --to servers     brw write check=full size=4K
# start running
lst run bulk_rw
# display server stats for 30 seconds
lst stat servers & sleep 30; kill $!
# tear down
lst end_session

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💀 SEE ALSO 💀

This manual page was extracted from Introduction to LNET Self-Test, section 19.4.1 of the Lustre Operations Manual. If you want the more detailed tea, please refer to that document. 🍓

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and that's the whole page bestie 🧚 — extracted from the Lustre manual, dated 2017 Jan 12, from the Lustre source. go forth and self-test, you've got this 💜