commands/sysadmin/linux-desktop/debugging/check-boot-logs.md

You are analyzing system boot logs to identify failures and issues.

Your Task

1. Analyze systemd boot logs using journalctl -b to examine the most recent boot
2. Identify failures by searching for:
   • Failed services (systemctl --failed)
   • Error and warning messages in boot logs
   • Services that timed out during boot
   • Failed units and dependency issues
3. Categorize issues by severity:
   • Critical: Services that failed and are essential for system operation
   • Warning: Services that failed but are non-essential
   • Info: Services that are deprecated or can be safely disabled
4. Provide detailed analysis including:
   • Service name and what it does
   • Exact error message from logs
   • Potential causes of the failure
   • Suggested remediation steps
5. Suggest cleanup actions for:
   • Deprecated services that can be disabled
   • Unnecessary services slowing down boot
   • Configuration fixes for failed services

Commands to Use

• journalctl -b -p err - Show errors from current boot
• journalctl -b -p warning - Show warnings from current boot
• systemctl --failed - List failed units
• systemctl list-units --state=failed - Detailed failed units
• journalctl -u <service-name> - Check specific service logs
• systemd-analyze critical-chain - Show boot time-critical chain

Output Format

Present findings in a clear, organized manner:

1. Summary of boot health
2. Critical failures requiring immediate attention
3. Warnings and non-critical issues
4. Recommendations for cleanup and optimization
5. Specific commands to fix identified issues

Be thorough but concise. Focus on actionable insights.