Community
Where to ask what
| You want to | Go to |
|---|---|
| Ask how to do something | GitHub Discussions or Discord |
| Discuss FEMU usage by email | The mailing list, femu@googlegroups.com. Ask to join on the group page; an owner approves requests, and the archive is visible to members |
| Report something broken | Issues |
| Propose a change | Pull requests |
| Report a potential vulnerability privately | Report a vulnerability on GitHub, as the security policy describes; never in a public issue |
Before opening an issue, include the mode, source commit, full device arguments, guest kernel and tools, the command that failed, and the expected and actual results. Remove credentials and private workload data from attachments.
Tell us you use FEMU
If FEMU is part of your research, course or product, post a short note in Show and tell: who you are, what you emulate, and what you wish FEMU did. It tells us which modes and features matter, and it is the evidence an open-source project needs to keep its funding. Papers also go on the papers page.
Project policies
These files live in the repository and are the authority when this site and they differ.
| File | What it covers |
|---|---|
| CONTRIBUTING.md | How to propose, test and submit a change |
| CODE_OF_CONDUCT.md | Expected behavior in every project space |
| SECURITY.md | Private reporting, response times and scope |
| MAINTAINERS | Who reviews which part of the tree |
| ROADMAP.md | What landed recently and what is planned |
| CITATION.cff | Machine-readable citation for the FAST '18 paper |
Licences for the code, the manual and this site are on the licensing page. How decisions are made is on the governance page.
Start contributing
The first model test is a small, runnable exercise with a downloadable patch. It needs a C compiler and Make, without a guest or KVM.
The developer learning path takes you from a standalone test through tracing a write, comparing policies, and preparing a change for review. You can contribute a clearer example or a reproducible bug report before changing the emulator.
For a course or reading group, Teach with FEMU organizes these activities by learning objective, prerequisites, and student deliverables.
What we could use help with
The project's own gaps are not a secret, and several are good entry points:
- Run the published configuration recipes in a guest and report the exact software versions and results.
- Add regression cases for command errors, namespace isolation, and interactions among supported policies.
- Improve examples that explain how to interpret counters and reproduce an experiment.
- Check mode documentation against guest-visible behavior and report differences.
Funding
FEMU's ecosystem work is supported by the U.S. National Science Foundation under Award No. 2550145, POSE Phase I: Toward a Community-Driven Fast Emulator (FEMU) Ecosystem for Next-Generation Storage Systems Research and Innovation, from June 1, 2026 to May 31, 2027.
The award funds scoping and planning for a sustainable, community-governed FEMU ecosystem, not new emulator features. Its three objectives:
- Ecosystem discovery and community engagement: learn who uses FEMU, for which use cases, and what keeps people from contributing.
- Contributor infrastructure and training: onboarding paths, continuous integration and testing.
- Governance and security: a transparent governance charter and security policies.
Any opinions, findings and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.