everything about linux distros
The previous chapter introduced cloud computing and the NIST definition with its five essential characteristics. This chapter goes deeper into the three service models that definition identifies: Infrastructure as a Service (IaaS), Platform as a Service (PaaS), and Software as a Service (SaaS). These are the categories that determine what the provider manages, what the…
The root password reset is the most common boot recovery procedure and the one most likely to appear on the LFCS exam as a practical task. The procedure has three stages: interrupt the boot to reach a shell that runs before authentication, remount the filesystem so it can be written, and change the password. The…
The previous chapters covered what cloud computing is and how the three service models — IaaS, PaaS, and SaaS — divide responsibility between the provider and the consumer. This chapter is about the three companies that dominate that market: Amazon Web Services (AWS), Microsoft Azure, and Google Cloud Platform (GCP). They are called the “hyperscalers”…
Partitioning is the act of dividing a physical disk into logical regions that the operating system treats as separate block devices. Every filesystem, swap area, and LVM physical volume begins as a partition or a whole disk. The LFCS objective is not about memorizing the fdisk menu; it is about understanding the two partition table…
Virtual machines and containers are both virtualization technologies. Both let you run isolated workloads on shared hardware. Both are fundamental to modern cloud infrastructure. But they operate at different layers of the stack, and the difference determines how much they cost, how fast they start, and how strongly they isolate. The LFCA exam places this…
fdisk is the traditional interactive partition editor for Linux, and it remains the tool the LFCS exam expects you to know for MBR disks. Modern versions of fdisk from util-linux also handle GPT, which means a single tool can inspect and modify both table types, but the menu flow and the partition-numbering rules differ between…
Docker is a platform for packaging, distributing, and running applications in isolated environments called containers. It was released in 2013 and is built on Linux kernel features — namespaces and control groups — that existed long before Docker existed. What Docker did was make those features accessible through a consistent toolchain and a standard packaging…
gdisk is the GPT-aware counterpart to fdisk. It shares the same interactive, menu-driven interface—the same letters for new, delete, type, print, write, and quit—but it operates on GUID Partition Table disks exclusively. Where fdisk asks whether a partition is primary or extended, gdisk does not, because GPT has no such distinction. Every GPT partition is…
In the previous chapter, you learned what Docker is and how containers differ from virtual machines. This chapter puts that theory into practice. You will run your first container, understand exactly what happens at each step, and learn the commands that form the foundation of every Docker workflow. The LFCA exam places containers under DevOps…
The distinction between an image and a container is the foundation of everything Docker does. New users conflate the two, and the confusion persists until they hit a problem that forces them apart: an image that cannot be deleted because a container is using it, a container that loses data because the image is read-only,…