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, especially important for web servers, proxies, and high-bandwidth applications.
  • Better Memory Management: Properly tuned virtual memory settings can reduce unnecessary swapping and improve system responsiveness, particularly critical for database servers and memory-intensive applications.
  • Enhanced Security: Security hardening options help protect against common network attacks, restrict access to sensitive kernel information, and reduce your server's attack surface.
  • Increased Stability: Appropriate limits for file handles, process counts, and connection queues prevent resource exhaustion and system crashes under heavy load.
  • Workload-Specific Tuning: Different server roles (web servers, databases, file servers, etc.) have unique requirements that can be optimized for better performance.

Our free sysctl.conf optimization tool automatically generates a complete configuration file based on your server's specifications, eliminating the need for manual calculations and research. Simply select your VPS plan, specify your server's role, choose security options, and the tool will create a tailored configuration file ready to use.

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: Select your VPS plan (or enter custom specifications), choose your server's role (web server, database, proxy, etc.), select any security hardening features you want, and optionally specify your kernel type. The tool will generate a complete, ready-to-use sysctl.conf file optimized for your specific configuration.

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.
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 logging of packets with impossible source addresses (martian packets). Helps detect spoofing attacks and network misconfigurations.

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, such as web servers, proxies, and CDN edge nodes.

Key network optimizations include:

  • TCP Buffer Sizes: Controls how much data can be buffered for sending and receiving, directly impacting network throughput.
  • Connection Limits: Maximum number of simultaneous connections and connection queues, important for high-traffic servers.
  • Congestion Control: Algorithms like BBR (Bottleneck Bandwidth and Round-trip) can dramatically improve performance on high-speed networks.
  • TCP Keepalive: Manages idle connection handling, important for maintaining stable connections in load balancers and proxies.

Memory Management Parameters

Virtual memory (VM) parameters control how Linux manages physical RAM, swap usage, and memory allocation. Proper tuning can prevent unnecessary swapping and improve performance for memory-intensive applications.

  • Swappiness: Controls the kernel's tendency to swap pages to disk. Lower values keep more data in RAM, ideal for database servers.
  • Cache Pressure: Determines how aggressively the kernel reclaims memory from filesystem caches, balancing between RAM and disk cache.
  • Dirty Page Ratios: Controls when cached data is written to disk, affecting both performance and data integrity.

Security Hardening Options

Our tool includes comprehensive security hardening options that help protect your server against common attack vectors and reduce information disclosure risks.

Network Security Hardening

Protects against network-based attacks including:

  • SYN Flood Protection: TCP SYN cookies prevent SYN flood attacks that can exhaust connection queues.
  • Reverse Path Filtering: Validates that packets arrive on the expected interface, preventing IP spoofing attacks.
  • ICMP Redirect Protection: Disabling redirect acceptance prevents route hijacking attempts.
  • Source Routing Protection: Blocks source-routed packets that can be used to bypass firewall rules.

Kernel Security Hardening

Additional kernel-level protections:

  • ASLR (Address Space Layout Randomization): Makes memory addresses unpredictable, hindering exploit attempts.
  • Kernel Pointer Restriction: Prevents information disclosure about kernel memory addresses.
  • ptrace Protection: Restricts process tracing capabilities that could be exploited for privilege escalation.
  • dmesg Restrictions: Prevents unprivileged users from viewing sensitive kernel log messages.

Privacy Features

Options to reduce information disclosure and minimize attack surface:

  • IPv6 Disabling: If not needed, disabling IPv6 reduces the attack surface.
  • SysRq Key Disabling: Prevents potential abuse of the magic SysRq key in remote environments.
  • ICMP Echo Ignoring: Hides your server from ping scans and basic network probes.

Server Role-Specific Optimizations

Different server roles have unique performance characteristics and requirements. 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.

Tor Relays

Optimized for long-lived connections with extended keepalive timers, increased port ranges, and settings that support stable, high-volume relay traffic patterns.

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 to handle screen updates and interactive sessions efficiently. Ideal for VNC, RDP, and remote desktop solutions.

Audio/Video Streaming Servers

Optimized for smooth media delivery with large network buffers to prevent buffering issues. Low swappiness and optimized cache retention for media files. Perfect for live streaming, on-demand video platforms, and audio streaming services.

WAF Frontends

Optimized for high connection capacity and security-focused traffic filtering. Very high connection limits similar to CDN servers, with settings optimized for analyzing and filtering web traffic before it reaches backend applications. Ideal for ModSecurity, Cloudflare, and other WAF solutions.

DNS Resolver/Authoritative DNS Servers

Optimized for fast query response times and high query throughput. Low-latency settings with efficient UDP/TCP handling for DNS queries. Ideal for BIND, PowerDNS, Unbound, and other DNS server software serving recursive or authoritative DNS queries.

Monitoring / Metrics Collectors

Optimized for handling many concurrent connections from monitored hosts and efficient time-series data writes. Balanced settings for collecting metrics while maintaining good I/O performance for storing historical data. 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, extended keepalive timers for peer connections, and optimized I/O settings for blockchain database operations. Ideal for Bitcoin, Ethereum, and other cryptocurrency full 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 provide stable, well-tested configurations. Most optimizations apply, but advanced features like BBR may require kernel modules.
  • XanMod Kernel: High-performance kernel with additional patches and schedulers. Supports BBR and other advanced TCP congestion control algorithms out of the box.
  • Liquorix Kernel: Low-latency kernel optimized for responsiveness. Excellent for real-time applications and multimedia workloads. Supports BBR.
  • ELRepo/Mainline Kernels: Alternative kernels for RHEL-based systems with additional hardware support and newer features.
  • pf-kernel: Performance-focused kernel with BFS scheduler, optimized for low-latency workloads on Debian/Ubuntu systems.

When using alternative kernels that support BBR congestion control, our tool automatically enables it for high-speed networks (5Gbps+) or bandwidth-intensive server roles (seedboxes, CDNs, Tor relays, streaming servers, and WAF frontends). BBR can significantly improve throughput and reduce latency compared to traditional congestion control algorithms like CUBIC.

Best Practices for Applying sysctl.conf Changes

  1. Backup First: Always create a backup of your existing /etc/sysctl.conf file before making changes: sudo cp /etc/sysctl.conf /etc/sysctl.conf.bak
  2. Test Gradually: Consider applying changes in stages, testing performance after each modification to identify any issues.
  3. Monitor Performance: Use tools like sysctl -a, netstat, ss, and system monitoring tools to verify changes take effect and observe performance improvements.
  4. Document Changes: Keep notes of any manual modifications you make beyond the generated configuration.
  5. Test After Reboot: Verify that settings persist after system reboot, as some settings may not apply correctly on all systems.
  6. Adjust as Needed: Monitor your server's performance and adjust parameters as your workload evolves or requirements change.

Note: Some sysctl parameters may not be available on all Linux distributions or kernel versions. If you encounter errors when applying the configuration, remove or comment out the problematic lines. The generated configuration is a starting point—fine-tuning may be necessary for your specific environment.