KernelKure.sh

Linux System Diagnostic & Repair Tool

Production-grade, interactive, root-privileged Bash script for diagnosing and repairing common Linux system failures — from boot issues to package corruption, disk errors, and log analysis.

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Overview

kernelkure.sh is a comprehensive, modular, and safe-to-use diagnostic and repair tool designed for Debian/Ubuntu, RHEL/Fedora/CentOS/Rocky/AlmaLinux, and Arch-based systems. It provides guided, step-by-step repairs with user confirmation before any destructive action, automatic configuration backups, detailed logging, and color-coded terminal output for clarity.

Whether you're facing:

• A black screen or GRUB failure
• Broken packages or lock files
• Full disks or corrupted filesystems
• Mysterious system crashes or service failures

…this script helps you diagnose, fix, and recover — safely and systematically.

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Supported Distributions

Family	Distributions
Debian	Ubuntu, Debian, Linux Mint, Pop!_OS, Kali, MX Linux, Raspberry Pi OS, etc.
RHEL	RHEL, CentOS, Rocky Linux, AlmaLinux, Oracle Linux, Fedora
Arch	Arch Linux, Manjaro, EndeavourOS, Garuda, Artix
Limited	openSUSE, Gentoo, Void (basic detection only — full support in future releases)

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Requirements

• Root privileges (sudo)
• Bash 4.0+
• Common system utilities: lsblk, grep, awk, sed, findmnt, journalctl, dmesg, etc.
• Package managers: apt, dnf/yum, or pacman (depending on distribution)
• Disk tools: fsck, blkid
• Optional: lspci, nvidia-xconfig (for GPU diagnostics)

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Quick Start

# Download or create the script
chmod +x kernelkure.sh

# Run interactively (recommended for beginners)
sudo ./kernelkure.sh

# Or run specific modules directly:
sudo ./kernelkure.sh --boot      # Fix boot/display issues
sudo ./kernelkure.sh --packages  # Repair broken packages
sudo ./kernelkure.sh --disk      # Check disk health
sudo ./kernelkure.sh --logs      # Extract critical logs
sudo ./kernelkure.sh --all       # Run everything (interactive prompts)

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Modules

1. Boot / Display Repair

• GRUB Reinstallation — Auto-detects boot device (UEFI/BIOS), backs up configs, reinstalls bootloader.
• GPU Conflict Detection — Checks for NVIDIA vs. Nouveau driver conflicts, AMD vs. Radeon, Intel i915.
• Black Screen Fixes — Audits Xorg/Wayland configs, checks display manager status, suggests kernel parameters.
• X11/Wayland Configuration — Regenerates configs, disables problematic overrides, enables DRM modesetting.

Ideal for when your system boots but shows a black screen or fails to start the GUI.

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2. Package Manager Fixes

• Lock Cleanup — Removes stale apt/dpkg, dnf/yum/rpm, or pacman locks safely.
• Dependency Repair — Runs --fix-broken, distro-sync, pacman -Sy, etc.
• Orphaned Packages — Identifies and optionally removes unused packages.
• Cache Cleanup — Frees space by cleaning package caches.

Never manually delete /var/lib/dpkg/lock again — let the script handle it safely.

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3. Disk & Filesystem Health

• Space Analysis — Highlights partitions above 80% usage, suggests cleanup commands.
• Inode Usage — Warns if inode tables are exhausted.
• fstab Validator — Checks for invalid UUIDs, missing mount points, and syntax errors.
• Filesystem Check (fsck) — Scans unmounted partitions for corruption, auto-fixes where possible.
• Read-only Root FS Alert — Detects emergency read-only mounts indicating serious errors.

Essential for servers or workstations running out of space or showing I/O errors.

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4. Critical Log Extraction

• System Journal Errors — Extracts the last 50 critical systemd journal entries.
• Kernel Issues — Searches for panics, oops, and segfaults in dmesg.
• OOM Events — Finds Out-of-Memory killer activity.
• Failed Services — Lists systemd units that failed to start.
• Service Error Summary — Shows the top 10 services generating errors.

Essential for post-mortem analysis or preparing bug reports.

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Backup & Logging

Automatic Backups

Before modifying any configuration file, the script creates timestamped backups under:

/var/backup/sys-repair-YYYYMMDD_HHMMSS/

Example structure:

/var/backup/sys-repair-20250405_143022/
├── etc/
│   ├── default/grub
│   └── grub.d/
├── boot/
│   └── grub/
│       └── grub.cfg
└── etc/X11/xorg.conf.d/

Restoring a backup:

cp /var/backup/sys-repair-*/etc/default/grub /etc/default/grub

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Detailed Logging

All actions are logged to:

/var/log/sys-repair.log

The log includes:

• Timestamps
• Operation type (INFO, SUCCESS, WARNING, ERROR)
• Commands executed
• User confirmations
• Module headers for easy navigation

Enable debug logging:

DEBUG=true sudo ./kernelkure.sh --boot

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Terminal UI Features

Feature	Description
Color-coded output	Red = Error, Green = Success, Yellow = Warning, Blue = Info
Bold headers and dividers	Visual separation between modules and sections
Interactive menus	Clear options with numbered selections
Confirmation prompts	Required before any destructive operation
Progress tracking	Avoids redundant operations within the same session

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Safety Features

Feature	Detail
User confirmation required	Before GRUB reinstall, lock removal, or any destructive action
Idempotent design	Will not re-run completed operations in the same session
Automatic config backup	Before every modification
Distribution-aware logic	Uses correct package manager and file paths per distro
Error trapping and cleanup	Removes temp files on exit or interrupt (via trap)

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Command-Line Options

Usage: sudo ./kernelkure.sh [OPTION]

OPTIONS:
    --all          Run all diagnostics and repairs interactively
    --boot         Run boot/display repair module only
    --packages     Run package manager fixes module only
    --disk         Run disk & filesystem health module only
    --logs         Extract critical system logs only
    --help, -h     Show this help message
    --version, -v  Show script version

EXAMPLES:
    sudo ./kernelkure.sh                 # Interactive menu
    sudo ./kernelkure.sh --all           # Full system check (with prompts)
    sudo ./kernelkure.sh --boot          # Fix boot issues only
    sudo ./kernelkure.sh --logs          # Extract error logs for review

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For Advanced Users

Customize Behavior

Set environment variables before running:

# Enable verbose debug logging
DEBUG=true sudo ./kernelkure.sh --boot

# Change backup directory (default: /var/backup/...)
export BACKUP_DIR="/opt/backups/sys-repair-$(date +%Y%m%d_%H%M%S)"
sudo ./kernelkure.sh --all

Extend Support

The script's modular structure makes it straightforward to add support for:

• Other init systems (runit, s6)
• Additional package managers (apk, pkg)
• Cloud-specific diagnostics (AWS, Azure metadata checks)
• Hardware RAID or LVM diagnostics

Contributions are welcome. Fork the repository and submit a pull request.

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License

MIT License — Free to use, modify, and distribute, including for commercial purposes.

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Support & Feedback

Found a bug or have a feature request? Open an issue on GitHub.

Author: Senior Linux Systems Engineer
Designed for production environments. Tested in crisis recovery scenarios.

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Final Notes

• Always reboot after major repairs, especially GRUB or driver changes.
• Review /var/log/sys-repair.log if something goes wrong.
• Keep recovery media ready when repairing bootloaders.
• Use --logs first to understand the problem before applying fixes.

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"An ounce of prevention is worth a pound of cure — but when your system breaks at 3 AM, this script is your emergency toolkit."

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Save this README alongside kernelkure.sh for quick reference during emergencies.