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Linux Server Performance Tuning

🚀 Linux Server Performance

Maximize throughput, concurrency & responsiveness for high-performance workloads

📖 Overview

This guide focuses on performance tuning of AlmaLinux / RHEL / CentOS servers, optimized for:

  • 🧠 High-memory & high-CPU usage workloads (PHP, Nginx, MySQL, etc.)
  • 🌐 Optimized network throughput
  • ⚙️ Better process and file handling
  • 💻 Server-side web applications or APIs

⚖️ 1. tuned: Dynamic Performance Profile

tuned is a system tuning daemon that adapts kernel and system settings automatically based on usage patterns.

🧰 Step-by-Step

📦 Install tuned:

dnf install tuned -y

🚀 Enable and activate the best profile:

systemctl enable --now tuned
tuned-adm profile throughput-performance

📊 Verify the active profile:

tuned-adm active

🔍 Other profiles:
Use tuned-adm list to view all available profiles like:

  • balanced (default)
  • latency-performance
  • throughput-performance ✅ (best for web/database servers)
  • network-latency, virtual-guest, etc.

⚙️ 2. Kernel Tweaks (/etc/sysctl.conf)

Tuning the kernel enhances file descriptors, network stack, and TCP behavior.

✍️ Add the following to /etc/sysctl.conf: 

# 🔢 Max open files
fs.file-max = 2097152

# 🧵 Network queue & backlog
net.core.somaxconn = 65535
net.core.netdev_max_backlog = 65535
net.ipv4.tcp_max_syn_backlog = 65535
net.ipv4.ip_local_port_range = 1024 65000

# 📡 TCP tuning
net.ipv4.tcp_congestion_control = bbr
net.ipv4.tcp_rmem = 4096 87380 67108864
net.ipv4.tcp_wmem = 4096 65536 67108864
net.core.rmem_max = 67108864
net.core.wmem_max = 67108864

# 📈 Window scaling & sync settings
net.ipv4.tcp_window_scaling = 1
net.ipv4.tcp_timestamps = 1
net.ipv4.tcp_sack = 1
net.ipv4.tcp_syncookies = 1

# 🚫 Disable IPv6 (if unused)
net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1

✅ Apply immediately:

sysctl -p

💡 Tip: BBR congestion control improves latency and throughput significantly on modern kernels.

🔐 3. Security Limits (/etc/security/limits.conf)

Linux uses ulimit values to define how many files, processes, and memory a user can use.

✍️ Edit /etc/security/limits.conf: 

# 🔓 File descriptor and process limits
* soft nofile 1048576
* hard nofile 1048576
* soft nproc 65535
* hard nproc 65535

# 🧠 Memory locking (disable swapping)
* soft memlock unlimited
* hard memlock unlimited

# 👤 Root user overrides
root soft nofile 1048576
root hard nofile 1048576

📁 Optionally create or edit /etc/security/limits.d/99-custom.conf to make these changes persistent for all sessions.

🧪 4. Verify Limits & Current Settings

Use these commands to verify applied limits:

ulimit -n # 🔍 Max open files
ulimit -u # 🔍 Max user processes
ulimit -a # 📜 View all current limits

✅ Expected output (after reboot or re-login):

  • open files: 1048576
  • max user processes: 65535

📌 Notes & Best Practices

🔎 Monitor your server regularly:

  • htop, top, glances – CPU/RAM/processes
  • iotop – Disk I/O
  • iftop, nload – Network usage
  • vmstat, iostat, netstat

🚩 Don’t over-tune blindly. Every server behaves differently based on its workload.

💡 Combine these settings with optimized web server configs (e.g., Nginx, PHP-FPM, MariaDB).

🗓️ Reboot your server after applying these changes to fully activate all system-level tweaks.