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Kernel: The Heart of Linux

The kernel is the core of Linux. It manages everything.

Here's the thing: You'll rarely touch the kernel. But understanding it helps you understand Linux.

What the Kernel Does​

The kernel:

  • Manages hardware
  • Controls processes
  • Handles memory
  • Provides system calls

My take: The kernel is like the engine. You don't see it. But everything depends on it.

Kernel Information​

View Version​

uname -r                         # Kernel release
uname -a                         # All system info

Output: 5.15.0-91-generic

Format: major.minor.patch-build

My take: uname -r shows kernel version. That's what you need to know.

Kernel Modules​

# List loaded modules
lsmod

# Module information
modinfo module_name

# Load module
sudo modprobe module_name

# Remove module
sudo modprobe -r module_name

My take: Modules extend kernel. Load them when needed.

Kernel Parameters​

sysctl: View/Set Parameters​

# View all
sysctl -a

# View specific
sysctl kernel.hostname

# Set parameter
sudo sysctl -w kernel.hostname=newhost

My take: sysctl controls kernel parameters. Use it to tune system.

When You'll Touch the Kernel​

You'll touch kernel when:

  • Loading drivers
  • Tuning parameters
  • Troubleshooting
  • Performance optimization

Most of the time: You won't touch it. It just works.

My take: Kernel usually works. Touch it when you need to.

Common Mistakes (I've Made These)​

  1. Changing parameters without understanding: Kernel parameters affect system. Understand before changing.

  2. Removing wrong modules: Removing modules can break things. Be careful.

  3. Not checking version: Kernel version matters. Check it.

  4. Too many parameters: Don't change too many parameters. Change what you need.

  5. Not testing: Test kernel changes. They affect the whole system.

Real-World Examples​

Check Kernel Version​

uname -r

Load Module​

sudo modprobe nvidia

View Parameters​

sysctl kernel.hostname

What's Next?​

Now that you understand the kernel, you understand Linux better. Or learn about Kernel Modules to extend functionality.

Personal note: The kernel seemed mysterious at first. Then I learned it. Now I understand Linux better. The kernel is the foundation. Learn it.