FreeBSD 12 – Common Problem 016 – devd Rules Do Not Trigger on USB Events

📖 ~1 min read

Table of contents

1. Symptom & Impact
2. Environment & Reproduction
3. Root Cause Analysis
4. Quick Triage
5. Step-by-Step Diagnosis
6. Solution – Primary Fix
7. Solution – Alternative Approaches
8. Verification & Acceptance Criteria
9. Rollback Plan
10. Prevention & Hardening
11. Related Errors & Cross-Refs
12. References & Further Reading

Symptom & Impact

Expected scripts do not run when USB devices are attached or removed.

Environment & Reproduction

Rules were recently added under `/etc/devd/` but no automation fires.

Root Cause Analysis

Rule match fields are wrong, or `devd` was not reloaded after changes.

Quick Triage

Confirm daemon is active and config files load.

service devd status
devd -d -f /etc/devd.conf
ls /etc/devd

Step-by-Step Diagnosis

Observe live events and verify match variables.

service devd stop
devd -d
usbconfig

Solution – Primary Fix

Correct rule conditions and restart daemon.

vi /etc/devd/usb-auto.conf
service devd restart
service devd status

Solution – Alternative Approaches

Use periodic polling for non-critical tasks if event matching is too device-specific.

Verification & Acceptance Criteria

Attach/remove tests trigger expected script and logging entries.

Rollback Plan

Revert to prior `devd` rule file and restart service.

Prevention & Hardening

Keep event tests for each hardware class and use explicit vendor/product matches.

Related Errors & Cross-Refs

No entries in daemon logs, scripts never invoked, incorrect `match` variables.

Related tutorial: View the step-by-step tutorial for freebsd-12.

View all freebsd-12 tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

`devd.conf(5)`, `devd(8)`, `usbconfig(8)`.