π ~1 min read
Table of contents
Symptom & Impact
Security updates arrive but kernel packages remain pending, leaving critical fixes unapplied.
Environment & Reproduction
Observed on systems with conservative unattended-upgrades origins or pending reboot requirements.
Root Cause Analysis
Policy settings or package holds prevent automatic kernel installation and activation.
Quick Triage
Check pending upgrades with apt list –upgradable and held packages via apt-mark showhold.
Step-by-Step Diagnosis
Inspect /var/log/unattended-upgrades/unattended-upgrades.log and confirm allowed origins in config files.
Solution – Primary Fix
Adjust unattended-upgrades policy, clear package holds, run sudo apt full-upgrade, and reboot into the new kernel.
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Solution – Alternative Approaches
Schedule periodic manual maintenance windows for kernel updates on systems requiring controlled reboots.
Verification & Acceptance Criteria
uname -r matches newly installed kernel version and no pending kernel updates remain.
Rollback Plan
Boot previous kernel from GRUB if compatibility issues appear after reboot.
Prevention & Hardening
Track reboot-required events and automate compliance checks for kernel patch latency.
Automate patch management and compliance across your fleet with our DevOps services.
Related Errors & Cross-Refs
Related notices include ‘/var/run/reboot-required’ and unmet dependencies blocking full-upgrade.
Related tutorial: View the step-by-step tutorial for Ubuntu 26.04 LTS.
View all Ubuntu 26.04 LTS tutorials on the Tutorials Hub β
Browse all common problems & solutions on the Tutorials Hub.
References & Further Reading
Ubuntu unattended-upgrades documentation and kernel lifecycle guidance for Ubuntu LTS.
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