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Linux Journal
Number of Followers: 25  Subscription journalISSN (Online) 1075-3583 Published by Belltown Media, Inc.  [1 journal]
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- Linux Performance Monitoring: Using Tools Like top, vmstat, and iostat
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Authors: George Whittaker
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by George Whittaker IntroductionLinux systems are renowned for their robustness and efficiency, making them a preferred choice for servers, desktops, and embedded systems. However, with great power comes the need for effective monitoring and maintenance. Performance monitoring is a critical aspect of system administration, ensuring that all processes and resources are functioning optimally. In this article, we'll delve into three essential tools for monitoring Linux performance: top, vmstat, and iostat.Understanding Linux Performance MetricsBefore diving into the tools themselves, it's crucial to understand the key metrics that indicate the health of a Linux system. These include CPU utilization, memory usage, disk activity, and network statistics. Monitoring these metrics helps in identifying bottlenecks, understanding resource usage, and troubleshooting performance issues.The top Commandtop is an interactive utility that provides a real-time view of the system's resource usage. It displays information about the most resource-intensive processes, CPU usage, memory usage, and much more.Launching and Reading topTyping top in your terminal will open a dynamic interface. The top portion shows overall system statistics, while the bottom lists individual processes. The CPU statistics show user and system time usage, while memory stats display used and free memory.Tips for Using top
Pressing Shift + F allows sorting processes based on different criteria like CPU or memory usage.
k is used to kill a process.
Shift + M sorts processes based on memory usage.The vmstat Commandvmstat, short for virtual memory statistics, is a tool that provides information about processes, memory, paging, block IO, traps, and CPU activity.Understanding vmstat OutputThe output of vmstat is divided into several columns showing process, memory, swap, io, system, and CPU information. This data is crucial for diagnosing performance issues, especially in cases of memory and swap usage.The iostat Commandiostat is used for monitoring system input/output device loading. It provides detailed reports about disk read/write and CPU utilization.Interpreting iostat OutputThe iostat output includes device utilization, providing insights into how effectively the system's storage subsystem is handling the workload. High wait times could indicate a need for better storage performance. Go to Full Article
PubDate: Thu, 23 Nov 2023 17:00:00 +000
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- Runlevels and the Boot Process in Linux
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Authors: George Whittaker
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by George Whittaker IntroductionLinux, an immensely powerful and versatile operating system, sits at the heart of countless applications, from tiny embedded devices to massive servers. A pivotal aspect for any user, whether a seasoned system administrator or a curious enthusiast, is understanding its boot process and runlevels. This article aims to demystify these concepts, illuminating the path Linux takes from power-on to a fully operational state, and explaining the intricacies of its runlevel system.Understanding the Linux Boot ProcessBIOS/UEFI StageThe journey of a Linux system begins with the Basic Input/Output System (BIOS) or the Unified Extensible Firmware Interface (UEFI). These firmware interfaces are responsible for performing the initial hardware checks and configurations. While BIOS is the traditional firmware used in many older systems, UEFI is its modern counterpart, offering enhanced capabilities such as secure boot and support for larger hard drives.Bootloader StageAfter the initial hardware setup, control is passed to the bootloader, the software responsible for loading the operating system. GRUB (Grand Unified Bootloader) is a common example, known for its flexibility in managing multiple operating systems. This stage involves selecting a kernel to boot and specifying any necessary parameters or options.Kernel InitializationUpon selection, the kernel, the core of the Linux operating system, is loaded into memory. This phase is crucial as the kernel sets up all the necessary drivers and subsystems required for the system's basic operations. During this stage, an initial RAM disk (initrd or initramfs) may be used to temporarily hold drivers and modules needed to boot the system.System InitializationFollowing the kernel initialization, the system’s primary initialization process begins. This stage is managed by an init system like SysVinit or systemd, which starts essential services, mounts filesystems, and ensures that everything required for a fully operational system is up and running.Linux RunlevelsDefinition and PurposeRunlevels in Linux are predefined states that a system can be in, each characterized by a certain set of services and processes that are either running or stopped. Understanding runlevels is crucial for managing a Linux system, especially when it comes to customizing its behavior for different scenarios.Types of RunlevelsLinux typically has seven runlevels, numbered from 0 to 6: Go to Full Article
PubDate: Tue, 21 Nov 2023 17:00:00 +000
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- Understanding the Next Wave of Desktop Environment Innovations
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Authors: George Whittaker
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by George Whittaker IntroductionLinux, the cornerstone of open source operating systems, has always been synonymous with flexibility and choice, particularly through its diverse range of desktop environments (DEs). These DEs are more than just user interfaces; they are gateways that define user interaction with the vast world of Linux. This article delves into the future trajectory of Linux DEs, exploring upcoming trends and innovations that are poised to redefine the Linux user experience.Historical ContextThe journey of Linux DEs has been a remarkable evolution, from rudimentary window managers like twm to sophisticated, feature-rich environments such as GNOME, KDE, and XFCE. Each step in this evolution has brought more intuitiveness, customization, and efficiency, catering to a broad spectrum of user preferences and system capabilities.Current Landscape of Linux Desktop EnvironmentsAs of 2023, the Linux DE landscape is vibrant and varied. GNOME and KDE Plasma lead in popularity, offering a blend of aesthetic appeal and functional richness. XFCE and LXQt remain favorites for those seeking lightweight alternatives, while Cinnamon and MATE cater to users who prefer a more traditional desktop feel. The common thread among these DEs is their commitment to customization, allowing users to tailor their computing experience to their liking.Emerging Trends in Linux Desktop Environments
AI and Machine Learning Integration: Future Linux DEs might leverage AI to automate tasks and provide personalized user experiences. Imagine a desktop that organizes your workflow based on your habits or offers suggestions to improve productivity.
Enhanced Graphics and Animations: The use of modern GPUs is not just for gaming. Linux DEs are increasingly incorporating sophisticated graphical elements and animations, making the desktop experience more visually engaging.
Touchscreen and Gesture Support: With the rise of touch-enabled devices, Linux DEs are evolving to support gesture controls and touchscreen inputs, making them more versatile in different hardware setups.
Cloud Integration and Remote Desktops: As the world moves towards cloud-based services, Linux DEs are expected to offer seamless integration with cloud storage and applications, and enhanced capabilities for remote desktop access. Go to Full Article
PubDate: Thu, 16 Nov 2023 17:00:00 +000
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- File Sharing on Linux Using NFS and Samba
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Authors: George Whittaker
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by George Whittaker IntroductionFile sharing is a fundamental aspect of networked computing, and in Linux environments, two of the most prevalent protocols facilitating this are NFS (Network File System) and Samba. This article aims to offer a quick view on using these systems, outlining their setup, configuration, and best practices.Understanding NFS (Network File System)NFS, developed by Sun Microsystems in 1984, is a distributed file system protocol that allows a user on a client computer to access files over a network much like local storage is accessed. NFS is particularly noted for its high performance and compatibility with various operating systems, making it a popular choice in Linux environments.Exploring SambaSamba, on the other hand, is a free software re-implementation of the SMB (Server Message Block) networking protocol, providing file and print services for various Windows clients. It plays a crucial role in integrating Linux/Unix servers and desktops into Active Directory environments, making file and print sharing between Linux and Windows seamless.Setting Up NFS on LinuxTo set up NFS, one needs a Linux server and client. The process involves installing NFS kernel server on the server, creating and exporting the directory to be shared, and then mounting that directory on the client machine.Setting Up Samba on LinuxSetting up Samba involves installing the necessary packages, configuring the smb.conf file to define shared directories and their permissions, and then managing access and security settings. Samba also allows for a wide range of configurations to cater to different network environments.NFS vs Samba: Comparing the Two SystemsWhile NFS is typically faster and more straightforward for Linux-to-Linux file sharing, Samba is indispensable for environments where Linux and Windows machines coexist. Both have robust security features, though their implementation differs.Advanced Tips and TricksAdvanced users can optimize NFS and Samba for better performance through various techniques such as adjusting the rsize and wsize parameters in NFS, or tuning the socket options in Samba. Automating tasks and integrating these systems with other services can also enhance their functionality.Future of File Sharing in LinuxThe landscape of file sharing is continuously evolving, with new protocols and technologies emerging. NFS and Samba are also being actively developed, with improvements in security, performance, and compatibility. Go to Full Article
PubDate: Tue, 14 Nov 2023 17:00:00 +000
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- Combining Configurable Button Widgets With Kwin's Shortcuts to Transform
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Authors: Doug Roberts
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by Doug Roberts If you are a KDE poweruser, you may already know and use one of KDE's most useful widgets: the configurable button. If you have never used these you will soon know how and if you apply all of what I am about to present, your experience of KDE will be smoother and more refined than it has ever been -- especially if your system (like mine) uses multiple displays.The first time I ever used the configurable button widget for something was to insert an xrandr command in one of these buttons. I was amazed at how wonderfully it worked, changing my external monitor's screen display with just a click. Here it is:xrandr --output VGA-1 --gamma .45:.50:.66.On my dual monitor setup, my 13 inch Dell laptop monitor needed to be brightened up considerably. But this made my external monitor way to bright and I needed to tone it down. Every boot, I had to open a Konsole and run that command. Now all I have to do is click the button as soon as the desktop loads.In this article I will take you way beyond that. I will show you how to use a plasma qdbus command to trigger with a mouse click any Kwin keyboard shortcut. I will even show you how to combine two or more shortcuts together and activate them with a mouse click. The one with three commands is my favorite:
Move the window to the next monitor.
Expand the window horizontally to the right.
Vertically maximize that window. All done with one click.Now that I have your attention let me show you how easy this is. All you need to know is a couple of qdbus commands.First you need to visit the KDE Store, download and install the configurable buttons widget. Just click to install. Then at your desktop click on the menu to add a widget and type "Configurable". See it' Good. That is what you are going to be doing a lot of.I am not a programmer. I got the qdbus commands courtesy of Luis Bocanegra via KDE Discuss. The first command is what you will need to find the names of all the possible Kwin keyboard shortcuts. Here it is:qdbus org.kde.kglobalaccel /component/kwin org.kde.kglobalaccel.Component.shortcutNamesOpen Konsole and put that command in it. When the huge list is generated, copy it to an editor for future reference.I my case I was asking Luis how to move a window to the next screen. He replied I could trigger that shortcut by its Kwin shortcut name, inserted into a similar qdbus command. You do it like this:qdbus org.kde.kglobalaccel /component/kwin org.kde.kglobalaccel.Component.invokeShortcut "Window to Next Screen";0You can try this one to get you started. I like to add an ;0 at the end of all these, as suggested by the button itself. That is the whole command you put into a configurable window button. There are two places to enter the command. Use them both. Go to Full Article
PubDate: Mon, 13 Nov 2023 17:00:00 +000
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- How to Monitor Your System with Zabbix
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Authors: George Whittaker
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by George Whittaker IntroductionIn the ever-evolving world of technology, system monitoring stands as the vigilant sentinel against potential downtimes and performance issues. For Linux systems, which are the bedrock of countless applications and services, monitoring is not just a preventative measure; it's an absolute necessity. Enter Zabbix, an open-source monitoring solution tailor-made for the expansive and versatile nature of Linux environments. This article delves into the intricacies of Zabbix, demonstrating why it is an indispensable tool for administrators seeking to harness the full potential of Linux system monitoring.Understanding ZabbixZabbix is not a newcomer on the monitoring scene. Since its inception in 2001, it has matured into a robust, feature-rich platform that boasts flexibility, scalability, and ease of integration. At its core, Zabbix offers real-time monitoring of servers, virtual machines, and cloud services. But what sets it apart is its ability to monitor all aspects of your network, from server health to application performance.A glance at Zabbix’s architecture reveals several key components working in tandem: the server, which is the central repository for data collection; the agents, which reside on the monitored hosts and gather operational data; the database, which stores all the monitoring statistics; and the web frontend, which presents a user-friendly interface for configuration and visualization of data.Setting up Zabbix for Linux MonitoringTo embark on the journey with Zabbix, one must first navigate through the installation process. While Zabbix supports numerous platforms, this article focuses on Linux, where it finds a natural complement in the operating system's open-source spirit.The installation process begins with ensuring your Linux server meets the necessary prerequisites, such as having a LAMP stack (Linux, Apache, MySQL/MariaDB, PHP) or equivalent technologies like Nginx or PostgreSQL. Next, you’ll download and install the Zabbix package suited for your Linux distribution, whether it be Ubuntu, CentOS, or another flavor.Once installed, the next steps involve setting up your Zabbix server, configuring the Zabbix agent on the hosts you wish to monitor, and fine-tuning the settings to begin data collection.Configuring and Customizing ZabbixWith Zabbix installed, you are now the master of your monitoring domain. The Zabbix dashboard serves as your mission control, providing a customizable interface from which you can oversee your Linux fleet. Here, you can create a personalized view that includes graphs, maps, and charts, all designed to give you a quick yet comprehensive overview of your system’s health. Go to Full Article
PubDate: Thu, 09 Nov 2023 17:00:00 +000
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- Navigating the Linux Textscape using Vim and Emacs
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Authors: George Whittaker
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by George Whittaker IntroductionIn the vast landscape of Linux, the prowess of a user is often measured by their fluency in text editing. Two titans dominate this realm: Vim and Emacs. These editors are not merely tools; they are ecosystems, philosophies, and communities that embody the essence of Linux's flexibility and power. This article dives deep into the intricacies of both, providing a roadmap for mastery over these keystroke kingdoms.History and PhilosophyThe tale of Vim begins with Bram Moolenaar's quest for an Amiga editor in 1991, which blossomed into the Vim we know today—a charitable software dedicated to improving the world one edit at a time. Emacs's saga, however, dates back to the 1970s with Richard Stallman, growing from a set of macros into an extensive self-documenting real-time display editor.Vim, derived from Vi IMproved, is the embodiment of efficiency. Its modal nature, where each mode serves a distinct purpose, is designed for minimal keystroke waste. Emacs, conversely, is an expansive workspace—a "do-it-all" environment where text editing is but the beginning.Getting Started with VimUpon entering the world of Vim, one finds themselves in Normal mode, a landscape of commands and shortcuts. Moving through text in Vim eschews the mouse in favor of h, j, k, and l. Inserting text requires a sojourn into Insert mode, achieved with a press of i, while Visual mode allows for text selection and manipulation.Editing in Vim is akin to choreographing a dance: x deletes a character, dw dispatches a word, and yy copies a line. Saving (:w) and exiting (:q) are but brief incantations away.Advancing with VimThe seasoned Vim user navigates files like a swift wind. Search and replace becomes a powerful gale with %s/old/new/g, while the .vimrc file and plugins transform Vim into a personalized fortress of efficiency.Getting Started with EmacsEmacs greets newcomers with a buffer—a canvas waiting for text. Navigation, though not modal like Vim, is keyboard-centric, with C-p, C-n, C-b, and C-f moving the cursor in familiar directions. Editing is immediate, with C-k cutting lines and C-/ for undoing missteps. Go to Full Article
PubDate: Tue, 07 Nov 2023 17:00:00 +000
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- Locating Leviathan Files in Linux
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Authors: George Whittaker
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by George Whittaker IntroductionIn the realm of Linux, where the command line is often the compass by which we navigate, the efficient management of disk space is crucial. Whether you’re sailing through personal projects or steering the ship of enterprise servers, large and forgotten files can be like hidden icebergs, threatening to sink your system's performance. This article serves as a detailed chart to help you uncover these lurking data giants. By mastering a few essential tools and commands, you’ll be able to not only find large files but also make informed decisions about how to handle them.Understanding File Sizes and Disk Usage in LinuxBefore embarking on our voyage to track down large files, it's essential to have a clear understanding of file size units. Linux measures file sizes in bytes, with common conversions being 1024 bytes to a kilobyte (KB), 1024 KB to a megabyte (MB), and so on up to terabytes (TB) and beyond. The du (disk usage) command is an invaluable tool in this journey, offering insights into the space consumed by files and directories. Similarly, df (disk free) tells us about the overall disk space and its availability, giving a bird's-eye view of our storage landscape.The find Command: Searching for Large FilesThe find command in Linux is a powerful utility for seeking out files that meet specific criteria. To hone in on large files, we can employ the find command with size options:find / -type f -size +100MThis command line incantation will list all files larger than 100 megabytes from the root directory. It's possible to modify the search criteria for a range of sizes or to execute actions on the files that are found, such as removing them with -exec rm {} \; appended to the command.The du Command: Assessing File and Directory SizesWhile find is excellent for pinpointing files, du dives deeper, allowing us to understand the sizes of directories as well:du -h --max-depth=1 /var sort -hr head -10This chain of commands will display the sizes of directories within /var, sort them in descending order, and show the top 10. This is incredibly useful for uncovering directories that have grown unexpectedly bulky. Go to Full Article
PubDate: Thu, 02 Nov 2023 16:00:00 +000
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- How to Configure Postfix Mail Server on Debian
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Authors: George Whittaker
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by George Whittaker IntroductionEmail remains a vital communication tool for both personal and business domains. Having your own mail server not only gives you control but also enhances the security and privacy of your communications. One of the popular mail servers is Postfix, known for its flexibility, reliability, and ease of configuration. Coupling Postfix with the robust Debian platform creates a dependable email server that can serve various communication needs. This guide aims to navigate you through the process of setting up your own mail server using Postfix on a Debian system.Pre-RequisitesBefore diving into the configuration, ensure the following:
Update your Debian system to the latest version using the apt package manager.
Obtain a domain name from a reputable registrar and configure the necessary DNS records.
Create the required user accounts and groups that will manage the mail server.Installing PostfixKickstart your mail server setup by installing Postfix:
Update the package list using the command sudo apt update.
Install Postfix and its dependencies using the command sudo apt install postfix.
During installation, you'll be prompted for basic configurations like the mail server type, system mail name, and others. Choose 'Internet Site' and input your domain name accordingly.Configuring PostfixNow, tweak the Postfix settings to suit your environment:
The main configuration files are located in /etc/postfix. The main.cf file holds the primary configurations, while master.cf defines the mail services.
Configure the hostname, domain, and network settings by editing the main.cf file.
Set up SMTP authentication and encryption to secure email transmission.Additional ConfigurationsFor a more robust mail server, consider the following configurations:
Configure mail aliases and virtual domains to handle multiple domains and reroute emails.
Set up spam filtering and antivirus scanning to protect against malicious emails.
Configure logging and monitoring to keep an eye on the mail server’s performance and security.Setting up Dovecot for POP/IMAPDovecot will manage the mailboxes and allow email retrieval:
Install and configure Dovecot using the command sudo apt install dovecot-imapd dovecot-pop3d.
Enable and configure POP3/IMAP protocols for email retrieval.
Integrate Dovecot with Postfix to allow seamless email delivery and retrieval.Testing the Mail ServerEnsure your mail server is functioning as expected: Go to Full Article
PubDate: Tue, 31 Oct 2023 16:00:00 +000
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- Harnessing Ubuntu Server with KVM and QEMU for Robust Virtualization
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Authors: George Whittaker
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by George Whittaker IntroductionVirtualization has become a cornerstone of modern computing, offering a myriad of benefits from cost savings to improved efficiency and scalability. Among the myriad of options available for server virtualization, Ubuntu Server stands out as a powerful and versatile choice. In this comprehensive guide, we'll delve into the intricacies of using Ubuntu Server for virtualization, focusing specifically on two critical tools: Kernel-based Virtual Machine (KVM) and Quick Emulator (QEMU).Understanding Virtualization in Ubuntu ServerVirtualization is the process of creating virtual versions of physical components, such as servers, storage devices, and network resources. It allows multiple virtual machines (VMs) to run on a single physical machine, effectively partitioning hardware resources. The benefits are manifold: improved resource utilization, reduced hardware costs, better disaster recovery solutions, and simplified management and maintenance tasks.Ubuntu Server, a popular choice for running virtualized environments, offers a stable, secure, and open-source platform. Its compatibility with various virtualization tools makes it a go-to choice for many IT professionals.KVM - The Kernel-based Virtual MachineKVM, integrated into the Linux kernel, turns the Linux OS into a type-1 (bare-metal) hypervisor. It leverages hardware virtualization features provided by processors (Intel VT or AMD-V), offering a high-performance environment for running VMs.Features and Benefits of KVM
Efficiency and Performance: KVM can run multiple VMs with near-native performance, making it ideal for high-demand environments.
Security: Being part of the Linux kernel, KVM benefits from Linux's security features.
Flexibility: It supports various guest operating systems, including Linux, Windows, and BSD.
Scalability: KVM can scale to meet the demands of extensive server environments, supporting large numbers of VMs.QEMU - The Quick EmulatorQEMU is a generic and open-source machine emulator and virtualizer. While it can function independently, it's often used in conjunction with KVM for enhanced performance. Go to Full Article
PubDate: Thu, 26 Oct 2023 16:00:00 +000
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