Free Linux sysctl.conf Optimization Tool

Generate optimized kernel parameter configurations for your Linux servers with our automated sysctl.conf generator. Tailored configurations based on your server's CPU, RAM, network speed, and workload type.

What is sysctl.conf and Why Should You Optimize It?

The /etc/sysctl.conf file contains kernel parameters that control various aspects of Linux system behavior, including network performance, memory management, file system operations, and security settings. By default, Linux uses conservative values suitable for general-purpose systems, but these may not be optimal for your specific server configuration and workload.

Key Benefits of Optimizing sysctl.conf:

  • Improved Network Performance: Optimized TCP/IP buffer sizes and connection handling can significantly improve network throughput and reduce latency.
  • Better Memory Management: Properly tuned virtual memory settings can reduce unnecessary swapping and improve system responsiveness.
  • Enhanced Security: Security hardening options help protect against common network attacks and reduce your server's attack surface.
  • Increased Stability: Appropriate limits for file handles, process counts, and connection queues prevent resource exhaustion.
  • Workload-Specific Tuning: Different server roles have unique requirements that can be optimized for better performance.
How to Use This Tool

This tool generates optimized sysctl.conf configurations tailored to your server's specifications and use case. All calculations are done automatically based on your CPU cores, RAM, network port speed, server role, and kernel type.

Steps:

  1. Select your VPS plan (or enter custom specifications)
  2. Choose your server's role (web server, database, proxy, etc.)
  3. Select any security hardening features you want
  4. Optionally specify your kernel type

The tool will generate a complete, ready-to-use sysctl.conf file optimized for your specific configuration. Simply copy the output and paste it into your /etc/sysctl.conf file.

System Configuration
Choose from one of our default plans or enter your own CPU and RAM allocations.

Stock Kernel
Default kernel provided by your Linux distribution. Recommended for most users. BBR congestion control may require loading the tcp_bbr module.
Compatible with: All distributions
What is the role of the server?

Choose from several pre-defined role profiles that best match the use case of your server.

General Purpose: Balanced settings for mixed workloads

Web Server: Optimized for HTTP traffic and many concurrent connections

Database Server: Optimized for data integrity and query performance

Proxy/Load Balancer: Optimized for forwarding traffic and connection handling

File Server: Optimized for disk I/O and throughput

Mail Server: Optimized for SMTP/IMAP/POP3 traffic patterns

Seedbox/Torrent Server: Optimized for high connection counts and file transfers

Tor Relay/Traffic Relay: Optimized for long-lived connections and privacy-focused networking

VPN Server: Optimized for stable, long-lasting connections

Game Server: Optimized for low latency and fast connection handling

CDN/Edge Server: Optimized for maximum throughput and connection scalability

Remote Desktop Server: Optimized for responsive screen sharing and remote access

Audio/Video Streaming Server: Optimized for smooth media delivery with large buffers

WAF Frontend: Optimized for high connection capacity and security-focused traffic filtering

DNS Resolver/Authoritative DNS Server: Optimized for fast query response and high query throughput

Monitoring / Metrics Collector: Optimized for many concurrent connections and time-series data writes

Blockchain Node: Optimized for stable peer connections and efficient blockchain data synchronization
Security & Privacy Features
Enable comprehensive network security features including reverse path filtering, disabling ICMP redirects, source routing, and other protections against network-based attacks. Essential for servers exposed to the internet.
Enable advanced kernel security features including Address Space Layout Randomization (ASLR), kernel pointer restriction, and core dump protections. Recommended for production servers.
Completely disable IPv6 on all interfaces if not needed. Reduces attack surface and prevents IPv6-related security issues. Only disable if you are certain IPv6 is not required.
Disable the SysRq key which can be used to send commands directly to the kernel, even from console. Disabling prevents potential security risks in shared or remote environments.
Prevent unprivileged users from viewing kernel log messages via dmesg. This protects sensitive system information and kernel addresses from non-root users.
Restrict process tracing capabilities to reduce risk of privilege escalation attacks. Prevents processes from attaching to other processes via ptrace, which can be exploited.
Disable the use of Berkeley Packet Filter (BPF) by unprivileged users. BPF can be exploited for privilege escalation. Only disable if no legitimate unprivileged BPF usage is required.
Ignore all ICMP echo requests (ping). Hides your server from ping scans and basic network probes. May affect legitimate monitoring tools.
Enable protections against symlink/hardlink attacks in world-writable directories. Prevents unprivileged users from exploiting race conditions with symbolic and hard links.

Understanding sysctl.conf Parameters

Network Parameters

Network-related sysctl parameters control TCP/IP stack behavior, connection handling, and buffer management. These settings are crucial for servers that handle high volumes of network traffic.

  • TCP Buffer Sizes: Controls how much data can be buffered for sending and receiving.
  • Connection Limits: Maximum number of simultaneous connections and connection queues.
  • Congestion Control: Algorithms like BBR can dramatically improve performance on high-speed networks.
  • TCP Keepalive: Manages idle connection handling for stable connections.

Memory Management Parameters

Virtual memory (VM) parameters control how Linux manages physical RAM, swap usage, and memory allocation.

  • Swappiness: Controls the kernel's tendency to swap pages to disk.
  • Cache Pressure: Determines how aggressively the kernel reclaims memory from filesystem caches.
  • Dirty Page Ratios: Controls when cached data is written to disk.
Security Hardening Options

Our tool includes comprehensive security hardening options that help protect your server against common attack vectors.

Network Security Hardening

  • SYN Flood Protection: TCP SYN cookies prevent SYN flood attacks.
  • Reverse Path Filtering: Validates that packets arrive on the expected interface.
  • ICMP Redirect Protection: Disabling redirect acceptance prevents route hijacking.
  • Source Routing Protection: Blocks source-routed packets.

Kernel Security & Privacy

  • ASLR: Makes memory addresses unpredictable, hindering exploit attempts.
  • Kernel Pointer Restriction: Prevents information disclosure about kernel addresses.
  • ptrace Protection: Restricts process tracing capabilities.
  • dmesg Restrictions: Prevents unprivileged users from viewing kernel logs.

Filesystem Protection

  • Protected Symlinks/Hardlinks: Prevents attacks in world-writable directories.
  • Protected FIFOs/Regular Files: Prevents opening files not owned by the user.

Server Role-Specific Optimizations

Different server roles have unique performance characteristics. Our tool automatically applies role-specific optimizations:

Web Servers
Optimized for high concurrent connection handling with increased SYN backlog, connection queues, and faster connection cleanup. Ideal for Apache, Nginx, and other web server software.
Database Servers
Emphasizes memory retention with low swappiness, optimized buffer sizes, and conservative memory overcommit policies. Best for MySQL, PostgreSQL, MongoDB, and similar databases.
Proxy/Load Balancers
Maximum connection handling capacity with large connection queues, aggressive timeout settings, and optimized for forwarding traffic efficiently between clients and backend servers.
File Servers
Larger network buffers for bulk transfers, optimized dirty page ratios for throughput, and increased filesystem cache retention for better file operation performance.
Seedbox/Torrent Servers
High connection limits with extended port ranges for numerous peer connections. Optimized for sustained high-throughput file transfers. Ideal for rtorrent, Deluge, and qBittorrent.
Tor Relays
Optimized for long-lived connections with extended keepalive timers, increased port ranges, and settings that support stable, high-volume relay traffic patterns.
VPN Servers
Configured for stable, long-lasting connections with IP forwarding enabled. Extended keepalive timers maintain tunnel connections. Ideal for OpenVPN, WireGuard, and other VPN solutions.
Game Servers
Low-latency optimizations with minimal swapping, fast connection handling, and optimized UDP buffers. Reduced network budget settings for faster packet processing.
CDN/Edge Servers
Maximum throughput and scalability settings with very high connection limits, optimized for serving cached content to large numbers of simultaneous clients.
Remote Desktop Servers
Optimized for responsive screen sharing and remote access protocols. Balanced memory settings with increased network buffers. Ideal for VNC, X2Go, and other Linux remote desktop solutions.
Audio/Video Streaming
Optimized for smooth media delivery with large network buffers to prevent buffering issues. Low swappiness and optimized cache retention for media files.
WAF Frontends
Optimized for high connection capacity and security-focused traffic filtering. Very high connection limits with settings for analyzing and filtering web traffic.
DNS Servers
Optimized for fast query response times and high query throughput. Low-latency settings with efficient UDP/TCP handling. Ideal for BIND, PowerDNS, and Unbound.
Monitoring / Metrics
Optimized for handling many concurrent connections and efficient time-series data writes. Perfect for Prometheus, InfluxDB, Graphite, and other monitoring solutions.
Blockchain Nodes
Optimized for stable peer connections and efficient blockchain data synchronization. Low swappiness for data integrity. Ideal for Bitcoin, Ethereum, and other cryptocurrency nodes.

Kernel Type Considerations

The Linux kernel type you're running can affect available optimization options, particularly for advanced features like BBR congestion control:

  • Stock Kernels: Default distribution kernels. BBR may require loading the tcp_bbr module.
  • XanMod Kernel: High-performance with BBR2/BBRv3 and BORE scheduler. Excellent for high-throughput servers.
  • Liquorix Kernel: Low-latency with BORE scheduler, optimized for responsiveness. Includes BBR support.
  • ELRepo/Mainline: Alternative kernels for RHEL-based systems with BBR support.
  • pf-kernel: Performance-focused with BORE scheduler for low-latency workloads. Includes BBR support.

When using alternative kernels, our tool automatically enables BBR for high-speed networks (5Gbps+) or bandwidth-intensive server roles.
Best Practices for Applying Changes
  1. Backup First: Create a backup with sudo cp /etc/sysctl.conf /etc/sysctl.conf.bak
  2. Test Gradually: Apply changes in stages, testing performance after each modification.
  3. Monitor Performance: Use sysctl -a, ss, and monitoring tools to verify changes.
  4. Document Changes: Keep notes of any manual modifications you make.
  5. Test After Reboot: Verify settings persist after system reboot.
  6. Adjust as Needed: Monitor and adjust parameters as your workload evolves.

Note: Some parameters may not be available on all distributions or kernel versions. Remove or comment out problematic lines if you encounter errors.