Learn Linux with Dan

Linux, networking, and cybersecurity made simple. Visual eBooks that make hard concepts stick. 100% handcrafted infographics by me in a sea of AI slop: https://study-notes.org

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Last Notes

2026-03-09 13:28:36 GMT

Linux provides special permissions like SUID, SGID, and the Sticky Bit that go beyond basic read, write, and execute permissions, modifying execution behavior and controlling file deletion in shared directories 😎👇
Find high-res pdf ebooks with all my Linux related infographics at https://study-notes.org
#linux #cybersecurity #infosec #informationsecurity #sysadmin
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2025-12-08 14:14:41 GMT

Here is a curated look at popular #opensource #pdf readers and viewing engines, from full applications to lightweight renderers, ranked by the number of #github stars received 😎👇
Find a high-res pdf book with all my #linux related infographics from https://study-notes.org
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2025-11-30 14:31:54 GMT

My underrated Linux pick is the lsof command. It tells you exactly which files are open and which processes are using them. Because Linux treats everything as a file, this tiny command ends up being insanely powerful and useful in everyday troubleshooting.
Here are useful lsof command examples 😎👇 #cybersecurity #infosec #sysadmin
Find high-res pdf books with all my #linux related infographics at https://study-notes.org
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2025-11-07 12:32:16 GMT

Are you trying to figure out which OS is good for you? For those clueless, here is an arbitrarily biased flow chart that can guide you 😎👇 #software #technology
Find high-res pdf books with all my #linux and #devops related infographics from https://study-notes.org
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2025-10-22 12:32:05 GMT

Adobe’s suite of creative tools covers everything from web design and logo creation to video and PDF editing, but you don’t have to stick with proprietary options.
Here are some #opensource alternatives to #adobe #software you can try instead 😎👇
Find high-res pdf books with all my #linux related infographics from https://study-notes.org
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2025-10-12 14:20:50 GMT

Thinking about leaving #windows for Linux? Here is a quick rundown of the pros and cons to help you decide whether to make the switch 😎👇
What is your take? Would you go Linux full-time?
Find high-res pdf books with all my #linux and #cybersecurity related infographics from https://study-notes.org
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2025-10-01 11:52:28 GMT

A FUSE filesystem is a user-space filesystem built on top of the Filesystem in Userspace (FUSE) kernel module, allowing developers to implement custom storage logic without writing kernel code
Here are a categorized list of Linux FUSE filesystems 😎👇 #sysadmin #devops
Find high-res pdf books with all my #linux and #cybersecurity related infographics from https://study-notes.org
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2025-09-11 11:48:03 GMT

OS-level sandboxing provides kernel-enforced isolation that restricts processes, filesystems, and resources, ensuring applications run in contained and controlled environments
Here is a comparison of sandboxing support across different OS 😎👇 #infosec #linux #macos #freebsd #windows
Find a high-res pdf book with all my #cybersecurity related infographics from https://study-notes.org/cybersecurity-ebook.html
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2025-09-05 11:49:45 GMT

This chart compares filesystem support across #windows, #macos and #linux showing which OS can support different filesystems natively without relying on third-party tools like fuse or wsl 😎👇
Find a high-res pdf book with all my Linux related infographics from https://study-notes.org/linux-ebook.html
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2025-07-15 12:02:32 GMT

The Linux /proc filesystem is a virtual interface that exposes live system information and kernel parameters, enabling users to monitor hardware and processes and adjust kernel settings at runtime
Here are a list of useful /proc entries 😎👇 #sysadmin #devops
Find high-res pdf books with all my #Linux related infographics at https://study-notes.org
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2025-07-13 12:46:21 GMT

The pv command is a handy but lesser-known tool that lets you monitor the progress of data through a pipe, displaying transfer speed, ETA, and total size. It’s often used with commands like tar, dd, or gzip to track the progress of file transfers, backups, or compression tasks
Here are useful pv command examples 😎👇 #sysadmin #devops #opensource
Find high-res pdf books with all my #linux related infographics at https://study-notes.org
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2025-07-04 12:52:37 GMT

POSIX Basic Regular Expressions (BRE) define a standardized syntax and behavior for regular expressions to ensure compatibility across Unix-like systems. Tools like grep, sed, and awk on Linux commonly support BRE for text processing
Here are useful examples of POSIX BRE 😎👇 #freebsd #sysadmin #devops #opensource
Find high-res pdf books with all my #linux related infographics at https://study-notes.org
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2025-07-02 12:00:53 GMT

On Linux, file extensions are mostly a matter of convention. They don’t determine how a file is handled. Instead, Linux relies on file permissions and internal metadata (like magic numbers) to identify and process files.
Still, learning common Linux file extensions is useful for understanding file types and managing files more effectively 😎👇 #sysadmin #devops #technology
Find high-res pdf books with all my #linux related infographics at https://study-notes.org
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2025-06-30 13:05:50 GMT

Modern high-speed Ethernet standards often use optical transceivers to transmit data over long distances via fiber optic cables. These transceivers are essential in data centers, enterprise networks, and carrier infrastructure where copper cabling is insufficient for speed or distance requirements
Here are different types of optical transceivers 😎👇 #datacenters #sysadmin #technology
Find high-res pdf books with all my #networking related infographics at https://study-notes.org
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2025-06-28 12:40:45 GMT

OpenSSH is a secure networking toolkit that implements the SSH protocol, enabling encrypted remote logins, file transfers, and secure tunneling
Here are a list of CLI utilities that come with OpenSSH 😎👇 #sysadmin #cybersecurity #infosec #devops
Find high-res pdf books with all my #Linux related infographics at https://study-notes.org
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2025-06-25 11:41:59 GMT

SSD form factors come in various shapes and interfaces, like 2.5”, M.2, and U.2, mSATA, each designed to suit different performance needs, physical constraints, and connection types in computing systems
Here are a quick summary on different types of SSD form factors 😎👇 #ssd #computer #tech
Find high-res pdf books with all my #technology related infographics at https://study-notes.org
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2025-06-20 11:47:23 GMT

The netcat command lets you read from and write to network connections using TCP or UDP. Its flexibility makes it a must-have for infosec professionals, who use it for tasks such as port scanning, banner grabbing, and setting up reverse shells during penetration tests.
Here are useful netstat command examples 😎👇 #sysadmin #devops #infosec #opensource
Find high-res pdf books with all my #Linux related infographics at https://study-notes.org
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2025-06-05 11:43:21 GMT

A DNS amplification attack is a DDoS technique where attackers use vulnerable DNS servers to send large volumes of unsolicited DNS responses to a victim, magnifying the traffic and overwhelming the target’s system 😎👇 #infosec #dns #technology
Find high-res pdf books with all my #cybersecurity related infographics at https://study-notes.org
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2025-05-27 11:43:21 GMT

USB standards define data transfer speeds, while connector types, often reused across versions, support multiple rates depending on the implementation
This infographic shows various USB connector types and the data transfer speeds associated with specific #usb standards 😎👇 #computer
Find high-res pdf books with all my #technology related infographics at https://study-notes.org
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2025-05-24 13:09:03 GMT

Securing Linux environments that run containerized workloads requires safeguarding active containers, scanning base images for vulnerabilities, hardening the host OS, and securing the container orchestrator, such as Kubernetes
Here are a list of container security tools available for #Linux 😎👇 #devops #docker #kubernetes #infosec
Find high-res pdf books with all my #cybersecurity related infographics at https://study-notes.org
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2025-05-18 13:25:18 GMT

Android’s file system is based on #linux and organized into distinct partitions: /system holds the core OS files, /data contains user apps and personal data, and /storage provides access to internal and external storage locations
Here is a description of #android file system hierarchy 😎👇
Find high-res pdf books with all my #technology related infographics at https://study-notes.org
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2025-05-12 11:51:48 GMT

UEFI and Legacy BIOS are two different systems that start up a computer when it powers on. Legacy BIOS is the older, traditional firmware, while UEFI is its modern replacement, offering more features, better security, and support for larger storage devices
Here is a quick comparison between the two 😎👇 #computer #hardware
Find high-res pdf books with all my #technology related infographics at https://study-notes.org
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2025-04-26 11:41:25 GMT

DNS is a distributed naming system that converts human-readable domain names into IP addresses. It works through a hierarchy of name servers, each handling part of the domain space, guiding queries step-by-step until the correct IP is found
Here is an illustration of how DNS works 😎👇 #technology #dns #sysadmin
Find high-res pdf books with all my networking related infographics at https://study-notes.org
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2025-04-16 11:22:52 GMT

Linux TUI (Text User Interface) software offers a user-friendly way to interact with applications directly from the terminal, using text-based menus and interfaces instead of a graphical desktop environment
Here are a categorized list of useful TUI software available on Linux 😎👇 #sysadmin #opensource
Find pdf books with all my #Linux related infographics at https://study-notes.org
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2025-04-13 13:56:28 GMT

WiFi mainly uses the 2.4 GHz and 5 GHz frequency bands, with 6 GHz gaining traction. Each band balances speed and range differently. Lower frequencies offer better coverage, while higher ones deliver faster data rates
Here is a quick comparison of 2.4 GHz and 5 GHz WiFi frequency bands 😎👇 #wifi #wireless #technology
Find high-res pdf books with all my networking related infographics at https://study-notes.org
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2025-04-10 11:47:48 GMT

Managed switches provide advanced control, monitoring, and traffic management features, allowing network admins to optimize performance and security—capabilities not available in unmanaged switches
Here are a list of common features found in managed network switches 😎👇 #technology
Find high-res pdf books with all my #networking related infographics at https://study-notes.org
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2025-04-08 11:44:41 GMT

Network monitoring is the process of capturing and analyzing traffic across OSI layers 2 to 4, offering visibility into how data moves through the network and how different protocols interact during communication
Here are Linux-based network monitoring tools, categorized by the OSI layer they operate on 😎👇 #sysadmin
Find high-res pdf books with all my #Linux related infographics at https://study-notes.org
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2025-04-07 11:41:16 GMT

Ethernet cables are classified into “CAT-N” categories (“CAT” meaning Category) based on their performance specifications, primarily bandwidth (MHz), maximum data rate (Mbps or Gbps), and transmission distance
Here are the different CAT types of Ethernet cables 😎👇 #datacenter
Find pdf books with all my #technology related infographics at https://study-notes.org
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2025-04-03 11:54:59 GMT

Ads in your web browser can be blocked using browser extensions, DNS filtering, or firewall rules, each working at different layers of the browser or network stack. These tools aim to stop ads from rendering on web pages, improving #privacy, reducing load times, and enhancing the browsing experience
Here are a list of ad blocking software 😎👇
Find high-res pdf books with all my #Linux and #cybersecurity related infographics at https://study-notes.org
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2025-03-29 11:52:31 GMT

How SSD wear leveling works
SSD wear leveling is a technique that distributes write and erase cycles evenly across memory cells to extend the lifespan and reliability of the drive 😎👇
Find high-res pdf books with all my #technology infographics at https://study-notes.org
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2025-03-26 11:43:49 GMT

A password manager helps you safely store and organize your passwords by locking them behind one master password, making it easy to access your accounts without sacrificing security.
Here is how a typical password manager works behind the scene 😎👇 #technology
Find high-res pdf books with all my #cybersecurity infographics at https://study-notes.org
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2025-03-25 11:44:19 GMT

Public DNS servers are freely accessible resolvers that offer DNS services with varying levels of security, including features like content filtering, DNS-over-TLS, and DNS-over-HTTPS
Here is a quick comparison of public DNS servers 😎👇 #technology
Find high-res pdf books with all my #cybersecurity infographics at https://study-notes.org
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2025-03-19 11:43:03 GMT

Wireshark’s packet filters make it easy to zero in on specific network traffic, whether you are looking at protocols, IP addresses, ports, or even packet contents
Here are useful Wireshark filter examples 😎👇
Find high-res pdf books with all my #linux and #cybersecurity related infographics at https://study-notes.org
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2025-03-14 11:55:25 GMT

Explore a collection of open-source privacy tools designed to enhance data security, encrypt communications, and protect online anonymity 😎👇 #opensource #privacy
Find high-res pdf books with all my #Linux and #cybersecurity related infographics at https://study-notes.org
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2025-03-13 11:54:14 GMT

A router performs Layer 3 packet forwarding based on destination IP addresses, enabling inter-network communication while also supporting auxiliary functions such as NAT, firewalling, VPN termination, and DHCP
Here is a quick overview of common router functions 😎👇 #technology
Find high-res pdf books with all my networking related infographics at https://study-notes.org
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2025-03-11 11:51:51 GMT

Ethernet speed evolution is driven by increasing demands for higher bandwidth, lower latency, and improved network efficiency to support data-intensive applications, cloud computing, and AI workloads
Here is how Ethernet standards have evolved over time 😎👇 #datacenters
Find high-res pdf books with all my #technology related infographics at https://study-notes.org
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2025-03-01 19:20:56 GMT

VisiData is a super handy terminal tool for exploring, analyzing and wrangling tabular data. It lets you load and manipulate huge datasets, CVS, JSON, Excel, you name it, right from the command line. You can sort, filter, aggregate and even visualize data on the fly, all in a slick spreadsheet-like interface.
VisiData is written in Python, so you can easily install it on #Linux, #macOS, #windows and BSD, anywhere Python can run 😎👇 #dataanalytics
https://www.visidata.org/
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2025-02-27 12:52:47 GMT

Data centers are the backbone of modern digital infrastructure, offering the computing power and storage needed for cloud services, enterprise applications, and global connectivity
Here are the top 10 data center providers based on the number of locations they operate worldwide 😎👇
Find high-res pdf books with all my #technology infographics at https://study-notes.org #datacenter
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2025-02-23 14:33:09 GMT

While the ps command is one of the most often used Linux utilities, many of you may not fully utilize its capabilities due to its complex and often confusing syntax
Here are a list of useful ps command examples 😎👇
Find high-res pdf books with all my #Linux related infographics at https://study-notes.org
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2025-02-15 13:11:09 GMT

The vast array of Linux distros reflects the diversity of user needs, offering solutions for everything from minimal setups to complex, specialized tasks
Which Linux distro is your choice?
Find high-res pdf books with all my #linux related infographics at https://study-notes.org
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2025-01-24 13:18:50 GMT

Linux PAM (Pluggable Authentication Modules) provides a flexible framework for managing authentication and access control policies for users and applications on Linux
Here is an overview of the Linux PAM architecture 😎👇
Find high-res pdf books with all my #linux and #cybersecurity related infographics at https://study-notes.org
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2025-01-21 13:10:17 GMT

Thinking about a new Linux laptop to run Linux on? Going with Linux laptop vendors can be a good option as they offer seamless hardware-software integration, pre-installed Linux distros, and guaranteed driver compatibility. Here are available Linux laptop vendors 😎👇
Find high-res pdf books with all my #linux and #cybersecurity related infographics at https://study-notes.org
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2025-01-12 12:52:07 GMT

Data center network topologies are designed to optimize scalability, fault tolerance, and efficient data flow between servers and devices, ensuring high availability and performance
Here are well-known network topologies deployed in today’s data centers 😎👇
Find high-res pdf books with all my networking related infographics at https://study-notes.org
#technology #datacenters #sysadmin
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2024-12-21 14:10:01 GMT

LVM is a disk management system of Linux that combines physical disks into a storage pool, enabling the creation of flexible logical volumes that can be resized or modified dynamically without rebooting the system
Here is a visual illustration of Linux LVM 😎👇
#linux #sysadmin
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2024-12-20 15:08:08 GMT

Layer 2 Ethernet security focuses on protecting network traffic within a local LAN from threats like unauthorized access, data interception, tampering, and flooding attacks by implementing various defensive measures 😎👇
#cybersecurity #infosec #sysadmin #networksecurity
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2024-12-15 15:08:31 GMT

Want more control and privacy without breaking the bank? Self-hosted alternatives to AWS let you customize your infrastructure to fit your needs while potentially cutting down on costs
Here are a list of self-hosted alternatives to AWS cloud services 😎👇
#aws #selfhosting #devops
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2024-11-25 12:47:29 GMT

In Linux, file permissions determine what access users, groups, and others have—whether they can read, write, or execute files. Since “everything is a file” in Linux, mastering file permissions is an essential step toward becoming a proficient Linux user
Here is a basic overview of Linux file permissions 😎👇
#linux #cybersecurity #infosec
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2024-11-17 14:16:12 GMT

RaspAP is a user-friendly, feature-rich software that transforms Debian-based devices, like the Raspberry Pi, into wireless access points with a customizable web interface
Here is the main highlight of RaspAP 😎👇
#linux #raspberrypi #opensource
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