CentOS Stream 10 – Common Problem 075 – Diagnosis and Fix

📖 ~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

System reboots after a crash but /var/crash contains no vmcore image.

Environment & Reproduction

Common when kdump fails to reserve crashkernel memory or target FS is full.

Root Cause Analysis

crashkernel kernel parameter missing or kdump service inactive.

Quick Triage

Check `systemctl status kdump` and `cat /proc/cmdline | grep crashkernel`.

Step-by-Step Diagnosis

Confirm reserved memory and target filesystem space.

Solution – Primary Fix

Set crashkernel via `grubby –update-kernel=ALL –args=crashkernel=2G-:512M` and reboot.

Solution – Alternative Approaches

Configure remote vmcore target if local disk is constrained.

Verification & Acceptance Criteria

After a forced `echo c > /proc/sysrq-trigger` test, vmcore appears in /var/crash.

Rollback Plan

Revert crashkernel size if it impacts host memory headroom.

Prevention & Hardening

Validate kdump after every kernel upgrade.

Related Errors & Cross-Refs

Linked to kernel oops and memory pressure events.

Related tutorial: View the step-by-step tutorial for centos-stream-10.

View all centos-stream-10 tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

kdump and crash analysis documentation for CentOS Stream 10.