diff --git a/2026/day-01/learning-plan.md b/2026/day-01/learning-plan.md new file mode 100644 index 0000000000..a31bd4415b --- /dev/null +++ b/2026/day-01/learning-plan.md @@ -0,0 +1,26 @@ +## 90-day personal DevOps learning plan + +# What is your understanding of DevOps and Cloud Engineering? +Devops is the bridge between developers and operation. + +The main goals are: +- Faster software delivery +- Higher deployment reliability +- Automation of repetitive tasks +- Better collaboration between teams +- Continuous monitoring and improvement + +Cloud Computing engineering focuses on designing, building, securing, and maintaining cloud-based infrastructure and services. +The cloud platforms like: AWS, Azure, GCP, utho + +# Why you are starting learning DevOps & Cloud? +- To switch and get more package +- To work on big startup, product base compnay, MNCs which help me to grow. +- Skilled to become good Devops Engineer + +# Where do you want to reach? +- I will work on big startup, product base compnay, MNCs. + +# How you will stay consistent every single day? +- I will commit daily in this repo +- I will win \ No newline at end of file diff --git a/2026/day-02/linux-architecture-notes.md b/2026/day-02/linux-architecture-notes.md new file mode 100644 index 0000000000..27ba304376 --- /dev/null +++ b/2026/day-02/linux-architecture-notes.md @@ -0,0 +1,91 @@ + +## The core components of Linux (kernel, user space, init/systemd) + +# Kernel +The kernel is the core(heart) of the operating system. +kernel is the bridge between software and hardware. + +It directly interacts with the hardware and manages: +- CPU scheduling +- Memory management +- Disk and file systems +- Device drivers +- Networking +- Security and permissions + +# User Space +User space is where normal applications run. +Examples: +- Bash shell +- Nginx +- Docker +- Python programs +- Editors like Vim + +Applications cannot directly access hardware. +They must request services from the kernel using system calls. + +Flow : User command ==> Shell ==> System Call ==> Kernel ==> Hardware + +# init System (systemd) +When Linux boots, the kernel starts the first process: +systemd: + +- Starts services during boot +- Manages background daemons +- Handles logging +- Restarts failed services +- Tracks dependencies between services + + + +## How processes are created and managed +A process is a running instance of a program. + +# Process Creation +Linux commonly creates processes using: + +fork() ==> creates a copy of the current process +exec() ==> replaces the copied process with a new program. + +# Process IDs (PID) +Every process has a unique number: + +You can inspect processes using: +ps aux +top +htop + +# Process States +Running, Sleeping, Stopped, Zombie + +# Signals +Linux controls processes using signals. +SIGTERM , SIGKILL , SIGSTOP , SIGCONT + + +## What systemd does and why it matters +systemd is the service manager used by most modern Linux systems. + +# Service Management +Start/stop/restart services. + +systemctl start nginx +systemctl stop docker +systemctl restart ssh + +# Boot Management + +systemctl enable nginx + +# Logging +systemd includes centralized logging. + +journalctl -u nginx + +# Automatic Recovery +systemd can restart failed services automatically. + +Restart=always + +