In the world of Linux, system tuning plays a crucial role in optimizing performance and efficiency. Whether you are a system administrator or a power user, understanding how to fine-tune your Linux system can greatly enhance its overall performance. This article aims to provide a factual and instructive guide on system tuning in the Linux environment, highlighting its importance and suggesting viable alternatives or equivalents when applicable.

Examples:

1. CPU Tuning:

   • Adjusting CPU frequency scaling: The Linux kernel provides various governors to control the CPU frequency scaling. By modifying the scaling governor, you can optimize the CPU's performance based on your system's needs. For example, to set the governor to "performance" mode, use the following command:

     $ echo performance | sudo tee /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor

   • Limiting CPU usage with cgroups: Control groups (cgroups) allow you to allocate resources, such as CPU and memory, to specific processes or groups of processes. By limiting CPU usage for certain processes, you can prevent them from consuming excessive resources and impacting system performance. To create a cgroup and limit CPU usage to 50% for a specific process, use the following commands:

     $ sudo cgcreate -g cpu:/my_cgroup
     $ echo 50000 | sudo tee /sys/fs/cgroup/cpu/my_cgroup/cpu.cfs_quota_us
     $ sudo cgexec -g cpu:my_cgroup <command>

2. Memory Tuning:

   • Adjusting swappiness: Swappiness determines how aggressively the Linux kernel swaps memory pages to disk. By modifying the swappiness value, you can control the balance between using swap space and keeping more data in physical memory. To set a lower swappiness value (e.g., 10), use the following command:

     $ echo 10 | sudo tee /proc/sys/vm/swappiness

   • Optimizing disk I/O with I/O schedulers: Linux provides different I/O schedulers that determine how the kernel handles disk I/O requests. By selecting the appropriate scheduler for your disk type (e.g., SSD, HDD), you can improve disk performance. For example, to set the CFQ (Completely Fair Queuing) scheduler for a specific block device, use the following command:

     $ echo cfq | sudo tee /sys/block/<device>/queue/scheduler