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The quiet force,Linux.

The heartbeat of modern infrastructure — cloud servers, Kubernetes clusters, desktops, and embedded devices alike. This guide covers the everyday sysadmin skills the KBVE stack leans on: extending storage with LVM, a productive ZSH shell, and the command-line essentials.

Essential commandsLVM storageZSH setup

Everywhere, often invisible

From the servers powering your favorite websites to the clusters orchestrating entire cloud platforms — understanding Linux means understanding the language of modern computing.

• Storage — resize volumes live with LVM.
• Shell — ZSH with Oh My Zsh and Powerlevel10k.
• Reference — the commands you reach for daily.

LVMStorage layer

ZSHShell

systemdInit system

GPLv2Kernel license

FeaturesFAQRelated

On this page

What this guide covers

Essential commands

The quick-reference toolkit — files, permissions, processes, systemd services, disk usage, and search.

LVM extension

Grow partitions, physical volumes, and logical volumes without disrupting a running system — ideal under Proxmox.

ZSH + Powerlevel10k

A faster, more expressive terminal — Oh My Zsh, themes, fonts, autosuggestions, and syntax highlighting.

Permissions first

Most "works for root, not the app" bugs are ownership problems — fix with chown and chmod, not by running everything as root.

Start here

Information

Linux is more than just an operating system, its the quiet force that keeps the modern world running. From the servers that power your favorite websites to the Kubernetes clusters orchestrating entire cloud platforms, Linux is everywhere, often invisible but always essential. Its open-source roots have created a culture of collaboration and curiosity, where anyone can peek under the hood, make changes, and share improvements with the world. Whether you’re deploying containers, managing infrastructure, or just exploring the command line, understanding Linux means understanding the language of modern computing.

This page focuses on two everyday sysadmin skills — extending storage with LVM and setting up a productive ZSH shell — plus an essential command reference for navigating any Linux system.

Daily drivers

Essential Commands

A quick reference for the commands you reach for constantly on any Linux box:

Command	Purpose
ls -lah	List files with sizes, permissions, and hidden entries
cd / pwd	Change directory / print working directory
cp / mv / rm	Copy, move, remove files
chmod / chown	Change file permissions / ownership
sudo	Run a command as root
ps aux / top	List / monitor running processes
systemctl status <svc>	Inspect a systemd service
journalctl -u <svc> -f	Follow a service’s logs
df -h / du -sh *	Disk free / directory sizes
grep -r "text" .	Recursively search file contents

Tip

Permissions are the most common source of “it works for root but not the app” bugs. ls -l shows the owner and mode; fix access with chown user:group file and chmod rather than running everything as root.

Grow without downtime

LVM

Logical Volume Management (LVM) provides a flexible way to manage storage on Linux, allowing you to resize, extend, or move partitions without disrupting your system. It’s especially useful when running Linux inside virtualized environments like Proxmox, where disk space can be expanded dynamically.

LVM Extension

1. Verify the current layout
   Check the existing disks, partitions, and volume groups to understand your current storage configuration.

           sudo lsblk
           # or
           sudo fdisk -l

2. Grow the partition to fill the disk Assuming your disk is /dev/sda and the partition is 3, extend the partition to use the new space.

           sudo growpart /dev/sda 3
           # Alternatively, open an interactive resizer:
           sudo cfdisk /dev/sda

3. Resize the Physical Volume (PV) After extending the partition, update the LVM physical volume to recognize the new size.

           sudo pvresize /dev/sda3

4. Extend the Logical Volume (LV) Grow the logical volume to use all the available free space.

           sudo lvextend -l +100%FREE /dev/mapper/ubuntu--vg-ubuntu--lv

5. Resize the filesystem Expand the filesystem so it can utilize the newly extended logical volume.

           sudo resize2fs /dev/mapper/ubuntu--vg-ubuntu--lv

6. Verify the result Check that the filesystem now reflects the expected capacity.

           df -h

Note

If you are using XFS instead of EXT4, replace the final resize command with:

    sudo xfs_growfs /

Caution

Always back up critical data before resizing partitions or volumes. You can inspect your volume group information at any time with:

sudo pvs && sudo vgs && sudo lvs

To extend the ubuntu--vg-ubuntu-lv after increasing the size of a physical volume from Proxmox

For the purposes of simplicity, I’m going to assume that the main volume you wish to extend is /dev/sda3.

• Check the current size with sudo lsblk or sudo fdisk -l
• Run either sudo growpart /dev/sda 3 or use sudo cfdisk to resize the /dev/sda3 to max size
• Extend the PV volume with sudo pvresize /dev/sda3
• Extend the LV to 100% with sudo lvextend -l +100%FREE /dev/mapper/ubuntu--vg-ubuntu--lv
• Resize the filesystem with sudo resize2fs /dev/mapper/ubuntu--vg-ubuntu--lv

A better terminal

ZSH

The Z Shell (ZSH) is a feature-rich shell that builds on Bash, offering improved autocompletion, better history management, and deep customization through plugins and themes.
It is the go to choice for developers who want a faster, more expressive terminal experience.

1. Install ZSH
   Make sure ZSH is installed on your system.

   sudo apt install zsh -y
   # or on Fedora / RHEL
   sudo dnf install zsh -y
   # or on Arch
   sudo pacman -S zsh

2. Set ZSH as the default shell

   chsh -s $(which zsh)

   Log out and back in for the change to take effect.

3. Install Oh My Zsh

   Oh My Zsh is a framework that simplifies managing your ZSH configuration and plugins.

   sh -c "$(curl -fsSL https://raw.githubusercontent.com/ohmyzsh/ohmyzsh/master/tools/install.sh)"

4. Add the Powerlevel10k theme

   Clone the Powerlevel10k theme into your Oh My Zsh themes directory.

   git clone --depth=1 https://github.com/romkatv/powerlevel10k.git ${ZSH_CUSTOM:-$HOME/.oh-my-zsh/custom}/themes/powerlevel10k

   Edit your ~/.zshrc and set:

   ZSH_THEME="powerlevel10k/powerlevel10k"

   Then reload:

   source ~/.zshrc

5. Install recommended fonts Powerlevel10k uses Nerd Fonts or Meslo LGS NF for icons and symbols.

   # Quick download and install for Meslo fonts (Mac/Linux)
   p10k configure

   Follow the prompts to install the suggested font and tweak your prompt style.

6. Enhance with plugins (optional) You can extend functionality with plugins like:

   plugins=(
       git
       zsh-autosuggestions
       zsh-syntax-highlighting
   )

   To install:

   git clone https://github.com/zsh-users/zsh-autosuggestions ${ZSH_CUSTOM:-~/.oh-my-zsh/custom}/plugins/zsh-autosuggestions
   git clone https://github.com/zsh-users/zsh-syntax-highlighting.git ${ZSH_CUSTOM:-~/.oh-my-zsh/custom}/plugins/zsh-syntax-highlighting

   Then reload once more:

   source ~/.zshrc

Tip

If you’re using VS Code’s integrated terminal or Windows Terminal, make sure you set the font to a Nerd Font (like Meslo LGS NF) in your settings for icons and glyphs to render correctly.

• ZSH Shell Official Page
• Oh My Zsh Official Page
• Powerlevel10K Repository
• One of the Best Tutorials by dev.to (Dec 2020)

Questions

Frequently asked

How do I extend a disk partition on Linux with LVM?

Grow the partition with growpart, update the physical volume with pvresize, extend the logical volume using lvextend -l +100%FREE, then resize the filesystem with resize2fs (EXT4) or xfs_growfs (XFS). Verify with df -h.

What is LVM in Linux?

Logical Volume Management is a storage abstraction layer that lets you resize, extend, or move volumes without repartitioning. It is especially useful in virtualized environments like Proxmox where disk size can grow dynamically.

How do I change my default shell to ZSH?

Install ZSH with your package manager, then run chsh -s $(which zsh) and log out and back in. Many users add Oh My Zsh and a theme like Powerlevel10k for autocompletion, history, and prompt customization.

What is the difference between ext4 and XFS when resizing?

Both are Linux filesystems, but they grow with different tools. Use resize2fs to expand an ext4 filesystem and xfs_growfs to expand XFS. XFS can only grow, never shrink, so plan capacity accordingly.

Keep exploring

Related applications

ProxmoxThe virtualization platform where LVM resizing pays off most.KubernetesCluster orchestration on top of the Linux foundation.DockerContainers, images, and Compose on the Linux kernel.