The Linux kernel is the core of the Linux operating system. It acts as the intermediary between applications and the hardware, managing CPU, memory, devices, filesystems, networking, and security. Think of the kernel as the operating system's control center. High-Level Architecture +------------------------------------------------------+ | User Space | |------------------------------------------------------| | Applications (Chrome, F

Introduction Docker is more than just a tool for running containers. To use Docker effectively in production, you need to understand how its architecture, networking, storage, orchestration, and troubleshooting work together. Think of Docker as a modern apartment complex: The Docker Engine is the building manager. Images are apartment blueprints. Containers are occupied apartments. Networks are the roads connecting apartments. Volumes are personal storage lockers. Docker Comp

Overview Modern applications need to run consistently across laptops, test environments, data centres, and public clouds. In the past, developers often heard: "It works on my machine!" This happened because applications depended on specific operating systems, libraries, and configurations that differed from one environment to another. Docker solves this problem by packaging an application and everything it needs into a single, portable unit called a container. Docker has beco

Introduction Kubernetes is designed to be self-healing, but that doesn't mean problems never occur. Applications may fail to start, Pods may keep restarting, nodes can become unavailable, or users may not be able to access services. The good news? Kubernetes provides powerful tools to diagnose almost every issue. Think of Kubernetes troubleshooting like a doctor diagnosing a patient: Check the symptoms. Identify the root cause. Apply the correct treatment. Verify recovery. Th

What is Kubernetes? Imagine you own a food delivery company with 500 restaurants across multiple cities. Each restaurant has: Chefs (Applications) Kitchen (Servers) Delivery staff (Networking) Store manager (Monitoring) Inventory (Storage) Now imagine thousands of customer orders arriving every minute. Questions arise: Which restaurant should prepare the order? What if one restaurant closes? What if demand suddenly doubles? How do you ensure customers always get their food? M

Upgrade and Patching Best Practices Regular upgrades keep the environment secure and compatible with vSphere and NSX. 🔹 Pre-Upgrade Checklist ✅ Verify compatibility matrix (vCD ↔ vCenter ↔ NSX ↔ VCF). ✅ Backup DB and config. ✅ Pause tenant tasks and notify customers. ✅ Snapshot vCD Cell VMs. ✅ Check free space (/opt and /tmp ≥ 5 GB). 🔹 Upgrade Process Stop vCD Service systemctl stop vcloud-director Install New Package rpm -Uvh vmware-vcloud-director-10.x.y.rpm Run DB Upgr