docs: Add doc for nano-v3

[yfw]

What does this PR do ?

Adds instructions for training nano-v3 with nemo rl.

Issues

List issues that this PR closes (syntax):

Usage

• You can potentially add a usage example below

# Add a code snippet demonstrating how to use this

Before your PR is "Ready for review"

Pre checks:

• Make sure you read and followed Contributor guidelines
• Did you write any new necessary tests?
• Did you run the unit tests and functional tests locally? Visit our Testing Guide for how to run tests
• Did you add or update any necessary documentation? Visit our Document Development Guide for how to write, build and test the docs.

Additional Information

• ...

Summary by CodeRabbit

Documentation

• Added comprehensive guide for post-training Nemotron 3 Nano model using NeMo RL.
• Includes step-by-step instructions for data preparation, repository setup, launch script configuration with required parameters, and training execution.
• Details resource requirements and environment configuration.

_{✏️ Tip: You can customize this high-level summary in your review settings.}

[coderabbitai]

📝 Walkthrough

Walkthrough

New documentation file introducing a guide for post-training the Nemotron 3 Nano model using NeMo RL. The guide covers data preparation, repository setup, launch script configuration with resource specifications, and execution instructions.

Changes

Cohort / File(s)	Summary
Documentation docs/guides/nemotron-3-nano.md	New guide file with step-by-step instructions for post-training Nemotron 3 Nano including data setup, NeMo RL repository cloning, launch script creation with environment variables and SLURM configuration, and training execution.

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~5 minutes

Pre-merge checks and finishing touches

❌ Failed checks (1 inconclusive)

Check name	Status	Explanation	Resolution
Title check	❓ Inconclusive	The title 'Add doc for nano-v3' is vague and generic, using non-descriptive terms that don't convey the specific content or purpose of the documentation being added.	Use a more descriptive title that clarifies what the documentation covers, such as 'Add guide for post-training Nemotron 3 Nano with NeMo RL' to better convey the documentation's scope and purpose.

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Test Results For Major Changes	✅ Passed	PR contains only documentation changes (71-line instructional guide) with no code modifications, features, or breaking changes.

✨ Finishing touches

• 📝 Generate docstrings

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch yifu/nano-v3-docs

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands and usage tips.}

[coderabbitai]

Actionable comments posted: 1

📜 Review details

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 669e70c and 08cc727.

📒 Files selected for processing (1)

• docs/guides/nemotron-3-nano.md

🧰 Additional context used

📓 Path-based instructions (2)

docs/**/*.md

📄 CodeRabbit inference engine (CODING_GUIDELINES.md)

Update docs/index.md when a new markdown doc is added under docs/**/*.md or a markdown file is renamed, ensuring the document appears in the most appropriate section

Files:

• docs/guides/nemotron-3-nano.md

!(**/tests/**|**/test_*.py|**/test_*.sh)

📄 CodeRabbit inference engine (CODING_GUIDELINES.md)

Add the NVIDIA copyright header to all Python files and shell scripts (excluding tests). The header should include the current year

Files:

• docs/guides/nemotron-3-nano.md

⏰ Context from checks skipped due to timeout of 90000ms. You can increase the timeout in your CodeRabbit configuration to a maximum of 15 minutes (900000ms). (4)

• GitHub Check: build-container / main
• GitHub Check: Lint check
• GitHub Check: Post automodel integration comment / Comment on PR
• GitHub Check: Post submodule check comment / Comment on PR

🔇 Additional comments (3)

docs/guides/nemotron-3-nano.md (3)

1-71: Verify that docs/index.md has been updated to include this new guide.

Per the coding guidelines, when a new markdown documentation file is added under docs/**/*.md, the docs/index.md file must be updated to ensure the document appears in the most appropriate section. Since this file is not included in the review context, please confirm that it has been updated to reference docs/guides/nemotron-3-nano.md.

🔎 How to verify

Check that docs/index.md contains an entry linking to the new guide. It should appear in a section like "Guides" or similar. For example:

- [Nemotron 3 Nano Post-Training Guide](guides/nemotron-3-nano.md)

---

64-64: Clarify the ray.sub script reference.

Line 64 references ray.sub without a full path or explanation. This file is not created or described in the documentation. Please clarify whether ray.sub is:

1. A file that users should have in their repository root
2. A file provided elsewhere in the NeMo RL repository
3. Something that needs to be created by the user

Adding a brief explanation or a link to the relevant documentation would improve clarity.

---

3-71: Documentation content looks solid.

The guide provides clear step-by-step instructions for data preparation, code checkout, launch script configuration, and training execution. The bash commands are syntactically correct, the data splitting logic is sound (using head -n -1000 for training and tail -n 1000 for validation), and the SLURM configuration is well-documented with helpful placeholders.

[terrykong]

nice. can we also have the front page readme news bullet for nano v3 point to this doc?

[yfw]

nice. can we also have the front page readme news bullet for nano v3 point to this doc?

Updated the existing bullet point to point to these instructions.

[terrykong]

@lbliii can you review?

[terrykong]

@lbliii is out currently, so we'll merge and can always do tech edit afterwards