Run your first COSMOS/ORBIT experiment end to end — reserve nodes, image them,
execute a built-in "Hello World" wireless experiment, and (optionally) save your image.
Almost every COSMOS/ORBIT experiment follows the same six-step life cycle:
reserve resources, log into the domain, load a disk image onto the nodes, power
the nodes on, run the experiment, and optionally save the modified image. This
tutorial walks through each step once so the pattern becomes second nature; later
tutorials assume you know it.
After completing this tutorial you will be able to:
omf load and power them on.| Difficulty | Beginner |
| Estimated time | 30 min |
| Domain / sandbox | Any sandbox (examples use sb1.cosmos-lab.org) |
| Topic group | Getting Started |
| Last verified | Not re-tested (migrated 2026-06-20) |
Background knowledge
Account & access
Devices / nodes
| Resource | Role | Qty | Notes |
|---|---|---|---|
| node1-1 | First experiment node | 1 | any sandbox node |
| node1-2 | Second experiment node | 1 | used by the hello-world-wireless experiment |
Disk images
| Image | Load onto | Provides |
|---|---|---|
| baseline.ndz | all reserved nodes | standard COSMOS baseline OS + OMF |
Software components
| Component | Version | Source |
|---|---|---|
| OMF (ORBIT Management Framework) | current | preinstalled on the console and in the baseline image |
Two nodes in one sandbox, controlled from the sandbox console over the control
network. The hello-world-wireless experiment uses one node as sender and one
as receiver over their wireless interfaces.
ssh <username>@console.sb1.cosmos-lab.org
omf load -i baseline.ndz -t all
omf tell -a on -t all
omf stat -t all
The six-step life cycle, start to finish:
Reserve a set of nodes from a domain to run your experiment on. See
Make a reservation. Wait for the approval email.
ssh <username>@console.sb1.cosmos-lab.org
See SSH access — set up keys and log into a console.
omf load -i baseline.ndz -t all
Installs the image on the nodes' disks. Nodes turn off automatically after imaging.
omf tell -a on -t all
Give them a moment to boot, then check with omf stat -t all before proceeding.
omf exec test:exp:tutorial:hello-world-wireless -- --res1 node1-1 --res2 node1-2
Runs the built-in "Hello World" wireless experiment using node1-1 and node1-2.
For analyzing the results, see
Tutorial 3 — Analyzing experiment results.
For the full command set, see the
OMF commands reference.
omf save -n node1-1
If you modified an image, save it before your time slot ends — otherwise your
changes are lost when the node is re-imaged.
omf stat -t all shows your nodes powered on, and omf exec completes without
errors and prints the experiment's output. The hello-world experiment reports
messages sent/received between the two nodes.
omf save -n node1-1 # only if you changed the image and want to keep it
omf tell -a offh -t all
| Symptom | Likely cause | Fix |
|---|---|---|
omf stat shows a node not POWERON after omf tell -a on |
node still booting | wait ~1 min and re-check before running the experiment |
omf exec can't reach a node |
node not imaged/on | re-run Steps 3–4; confirm with omf stat |
Author(s): COSMOS team · Last verified: Not re-tested (migrated 2026-06-20) · Tested image/release: baseline.ndz · Tags: getting-started, omf, basics