Overkill Linux Documentation

Complete reference for installing, configuring, and mastering Overkill Linux v2.0 Katana.

Overview

Overkill Linux is a Debian-based Linux distribution that uses the KDE Plasma desktop environment. It offers customized editions tailored to every user type and need -- developers, gamers, multimedia creators, scientists, crypto users, engineers, and students.

Through the Overkill System Manager, all required packages for each edition are downloaded and kernel settings are applied with a single click. The System Manager also provides ZRAM support, NVIDIA driver installation, package management, DNS configuration, browser installation, and general system administration tools.

The goal of Overkill is to provide an effortless and fast workstation setup for every user. One ISO, install your preferred edition after boot, and your system is ready.

Project History

Overkill Linux was formerly known as Linux Megamix. The project was evolved and renamed due to several factors:

• Installer issues -- The original debian-installer and squashfs copy mechanism caused reliability problems during installation
• Low usability -- The old system lacked a graphical management tool, requiring manual configuration
• Maintenance overhead -- Maintaining separate ISO images for each edition was unsustainable; the new single-ISO approach with post-install edition selection greatly reduces maintenance burden
• Limited flexibility -- The old system did not support combining editions; the new Mix system allows combining Developer + Gaming, Developer + AI, and other combinations

What changed in 2.0 "Katana"

• Single ISO architecture -- editions are installed after boot, not baked into separate images
• Overkill System Manager (PyQt6 GUI) for graphical system management
• Kernel tuning profiles updated and expanded (gaming, multimedia, AI, hardened)
• New editions: Lite variants (Gaming Lite, Dev Lite, Dev+Gaming Lite), Gamebox, and Mix combinations
• New KDE Plasma desktop configuration
• Conky desktop monitor showing system info, edition, performance, storage, network, and battery
• Conky Manager tool for enabling/disabling the desktop monitor from terminal

System Requirements

Installation

1. Download the ISO

Download overkill-2.0-amd64.iso from SourceForge. After downloading, verify the file integrity:

sha256sum overkill-2.0-amd64.iso

Expected checksum:

349c1ee8d1fda9c94dc098420e75a0f587e5e5adb3876c2e9ce8a8162fc245dd

2. Create a Bootable USB

Flash the ISO to a USB drive (8 GB minimum). The USB contents will be erased.

Linux:

sudo dd if=overkill-2.0-amd64.iso of=/dev/sdX bs=4M status=progress oflag=sync

Replace /dev/sdX with your USB device (use lsblk to identify it). Do not point to a partition (e.g., /dev/sda1), use the whole disk (e.g., /dev/sda).

Windows: Use Rufus or balenaEtcher.

macOS: Use balenaEtcher, or dd in Terminal.

3. Boot from USB

Reboot your machine and enter the BIOS/UEFI boot menu (typically F12, F2, Del, or Esc during POST). Select your USB device. The Debian installer will launch.

4. Complete the Installer

The Debian installer will guide you through disk partitioning, user account creation, timezone, and locale setup. The KDE Plasma desktop and core system packages are pre-installed on the ISO -- no additional desktop selection is needed.

First Boot

After installation, log in to KDE Plasma. The system ships with the base desktop and Overkill System Manager pre-installed. No edition is active by default.

To set up your workstation:

1. Open the Applications Menu and launch Overkill System Manager.
2. Browse the 20 available editions in the Editions tab and select the one that matches your workflow.
3. Click the Install button. The system will download and configure all packages automatically.
4. Reboot to apply kernel tuning profiles (if applicable to your edition).

Edition System

The edition system is the core feature of Overkill Linux. Each edition defines:

• APT Packages -- System-level software from Debian stable repositories (compilers, libraries, CLI tools, drivers)
• Flatpak Applications -- Sandboxed desktop apps from Flathub (IDEs, games, wallets, browsers, AI clients)
• Tuning Profile -- Optional kernel-level configuration (sysctl parameters, GRUB settings, module blacklisting, firewall rules)

Only one edition can be installed at a time. The system enforces this by checking for an existing edition before allowing a new installation. The edition state is stored in /usr/share/edition/edition.conf.

Full Edition List

Tuning Profiles

Tuning profiles modify kernel parameters, boot configuration, and system services to optimize performance for specific workloads.

Gaming Tuning

• Reduced vm.swappiness to keep games in RAM
• Increased vm.max_map_count for large game maps
• Optimized I/O scheduler and writeback settings
• Network latency optimization (TCP nodelay, reduced keepalive)
• Hugepages configuration for memory-intensive games
• GRUB parameters for performance-oriented boot

Multimedia Tuning

• Low-latency audio configuration (reduced buffer sizes)
• Balanced I/O writeback for sustained read/write
• Optimized memory management for large media files
• PipeWire/JACK-friendly kernel parameters

AI Tuning

• Maximized vm.max_map_count for large dataset mapping
• GPU memory allocation optimization
• Increased file descriptor and inotify limits
• Large I/O buffer configuration for model loading

Hardened Tuning

• Sysctl kernel lockdown parameters (see Sysctl Tuning)
• GRUB boot security parameters (see Hardening Overview)
• Vulnerable kernel module blacklisting (see Module Blacklisting)
• nftables firewall (Hardened Edition only, see nftables Firewall)

Switching Editions

To switch from one edition to another:

1. Open System Manager and click Uninstall Current Edition, or run sudo overkill-setup-cli uninstall-edition
2. The system will purge all edition-specific APT packages and Flatpak apps, and revert any kernel tuning changes
3. Install the new edition
4. Reboot to apply the new tuning profile

GUI Overview (Recommended)

The Overkill System Manager is the primary and recommended way to manage your Overkill Linux system. It is a full-featured PyQt6 graphical application with a modular interface -- left sidebar for navigation and a main content area with real-time console output for each operation.

The GUI is designed to be the single point of control for your entire system. All edition installations, package management, driver setup, DNS configuration, ZRAM management, browser installation, and log viewing can be done through the graphical interface without ever touching a terminal.

Modules

CLI Reference (Alternative)

The CLI backend is located at /usr/bin/overkill-setup-cli. It must be run as root. Without arguments, it launches an interactive TUI menu. With a subcommand, it runs non-interactively.

sudo overkill-setup-cli [subcommand] [arguments...]

CLI Examples

# Install the Gaming Edition
sudo overkill-setup-cli install-edition 5

# Check which edition is installed
sudo overkill-setup-cli status

# Uninstall the current edition
sudo overkill-setup-cli uninstall-edition

# Switch DNS to Cloudflare
sudo overkill-setup-cli set-dns cloudflare

# Set custom DNS servers
sudo overkill-setup-cli set-dns custom 1.1.1.1 9.9.9.9

# Enable ZRAM compressed swap
sudo overkill-setup-cli zram install
sudo overkill-setup-cli zram enable

# Install NVIDIA drivers
sudo overkill-setup-cli install-nvidia

# Install a Flatpak application
sudo overkill-setup-cli install-flatpak com.valvesoftware.Steam

# View last 50 lines of kernel log
sudo overkill-setup-cli view-log kernel 50

# Full system update
sudo overkill-setup-cli sys-update

DNS Configuration

Overkill Linux configures DNS persistently by combining two mechanisms:

1. Writing nameserver entries to /etc/resolv.conf
2. Creating a NetworkManager drop-in config at /etc/NetworkManager/conf.d/90-dns-manual.conf with dns=none

This prevents NetworkManager from overwriting your DNS settings when network connections change, reconnect, or when the system reboots.

Available Presets

Reverting DNS

To restore NetworkManager-managed DNS, remove the drop-in and restart:

sudo rm /etc/NetworkManager/conf.d/90-dns-manual.conf
sudo systemctl restart NetworkManager

ZRAM Setup

ZRAM creates a compressed block device in RAM that functions as swap space. This is faster than disk-based swap and particularly beneficial on systems with limited RAM.

# Install the zram-tools package
sudo overkill-setup-cli zram install

# Enable ZRAM swap (starts the systemd service)
sudo overkill-setup-cli zram enable

# Check current ZRAM status and usage
sudo overkill-setup-cli zram status

# Disable ZRAM swap
sudo overkill-setup-cli zram disable

NVIDIA Drivers

The System Manager provides one-click NVIDIA proprietary driver installation:

sudo overkill-setup-cli install-nvidia

This will:

• Detect your NVIDIA GPU model
• Install the appropriate nvidia-driver package from Debian non-free repositories
• Configure kernel modules for the NVIDIA driver
• A reboot is required after installation

Browser Management

Overkill ships with 12 browser options, installable and removable through System Manager:

Conky Manager

Overkill Linux ships with a Conky desktop monitor that displays real-time system information (OS, edition, kernel, uptime, CPU, RAM, storage, network, battery). The Conky Manager is a terminal tool for enabling or disabling the Conky autostart.

To launch Conky Manager, open a terminal and run:

conky-manager

The tool presents an interactive menu:

==================================
  Overkill Conky Manager
==================================

Overkill Conky: Enabled
Conky Reanchor: Enabled

==================================
1) Enable Conky (with Reanchor)
2) Disable Conky (with Reanchor)
3) Exit
==================================

• Option 1 -- Enables both the Conky widget and the Reanchor service (which repositions Conky on resolution changes). Both will start automatically on next boot.
• Option 2 -- Disables both. Neither will start on next boot.
• Option 3 -- Exit the tool.

Hardening Overview

The Hardened Edition (ID 6) and Hardened Mix editions apply a comprehensive security stack consisting of four layers:

1. Sysctl Parameters -- Kernel-level security settings applied via /etc/sysctl.d/
2. GRUB Boot Parameters -- Security-focused kernel command-line parameters
3. Module Blacklisting -- Blocking vulnerable or unnecessary kernel modules via /etc/modprobe.d/
4. nftables Firewall -- Network-level filtering (Hardened Edition only, not applied to "Hardened No FW" profiles)

Additionally, the Hardened Edition installs the following security applications:

• KeePassXC -- Offline password manager with TOTP support
• Kleopatra -- GPG key management and certificate manager
• Cryptomator -- Transparent client-side encryption for cloud storage (Flatpak)
• Warp -- Encrypted file transfer (Flatpak)

nftables Firewall

The nftables firewall is applied only by the Hardened Edition (ID 6). It replaces any existing iptables rules and configures a stateful packet filter.

Key Rules

• INPUT chain: Default policy DROP. Only established/related connections and explicitly allowed ports are accepted.
• OUTPUT chain: Default policy ACCEPT. All outbound traffic is unrestricted.
• FORWARD chain: Default policy DROP.
• Bogon filtering: Drops packets from known non-routable source IPs.
• SYN flood protection: Rate-limited SYN packet acceptance.
• ICMP rate limiting: Prevents ping floods while allowing normal ICMP.

Allowed Inbound Ports

Sysctl Tuning

Hardened editions apply the following sysctl parameters (non-exhaustive):

• net.ipv4.tcp_syncookies = 1 -- SYN flood protection
• net.ipv4.conf.all.accept_redirects = 0 -- Block ICMP redirects
• net.ipv4.conf.all.rp_filter = 1 -- Reverse-path filtering (anti-spoofing)
• net.ipv4.conf.all.log_martians = 1 -- Log suspicious packets
• kernel.core_pattern = /dev/null -- Disable core dumps
• kernel.kptr_restrict = 2 -- Hide kernel pointers
• kernel.yama.ptrace_scope = 2 -- Restrict ptrace

Module Blacklisting

Hardened editions block the following kernel module categories via /etc/modprobe.d/:

• USB Storage -- usb-storage, uas (prevents unauthorized USB data exfiltration)
• FireWire -- firewire-core, firewire-ohci, firewire-sbp2 (DMA attack vector)
• Bluetooth -- bluetooth, btusb (wireless attack surface reduction)
• Legacy Network -- dccp, sctp, rds, tipc (rarely-used protocols with known vulnerabilities)
• Miscellaneous -- thunderbolt, cramfs, freevxfs, jffs2, hfs, hfsplus, udf

File Locations

Contact

For bug reports, feature suggestions, or any other inquiries, please visit Nixovena Labs website:

You can find our community forums, social media links, and direct contact methods there.

Troubleshooting

Edition install fails

Ensure you have an active internet connection and that APT repositories are reachable. Run sudo apt update manually to check. If a previous edition is installed, uninstall it first.

nftables service fails to start

Check the ruleset syntax: sudo nft -c -f /etc/nftables.conf. If the rules are corrupt, restore the backup: sudo cp /etc/nftables.conf.bak /etc/nftables.conf && sudo systemctl restart nftables.

DNS resets after reboot

Verify that the NetworkManager drop-in exists: cat /etc/NetworkManager/conf.d/90-dns-manual.conf. It should contain [main] and dns=none. If missing, re-apply DNS through System Manager.

NVIDIA driver not loading

Reboot after installation. If the driver still does not load, ensure Secure Boot is disabled in your UEFI settings and try reinstalling through System Manager (Drivers module).

Conky shows "None" for edition

This is normal if no edition has been installed yet. Install an edition through System Manager and the Conky display will update automatically.

Flatpak apps not appearing in menu

Log out and back in. KDE caches the application menu and requires a session restart to detect newly installed Flatpak applications.

ZRAM not activating

Open System Manager, go to the ZRAM module, and click INSTALL first, then ENABLE. Click STATUS to verify it is active.