How to use KVM from the command line on Debian or Ubuntu

There are different ways to manage virtual machines (VMs) running on KVM hypervisor. For example, virt-manager is a popular GUI-based front-end for VM management. However, if you would like to use KVM on a headless server, GUI-based solutions will not be ideal. In fact, you can create and manage KVM VMs purely from the command […]
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What are good web server benchmarking tools for Linux

As far as web server performance is concerned, there are many different factors at play, e.g., front-end application design, network latency/bandwidth, web server configuration, server-side in-memory cache, raw hardware capability, server load of shared hosting, etc. To compare and optimize web server performance under such a wide array of factors, we often perform load test […]
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How to secure your Linux environment with Nitrokey USB smart card

With the mounting online security risks, simple one-step security no longer suffices, and people resort to multiple layers of security to thwart increasingly sophisticated attacks on their digital assets and online privacy. An advanced form of security defense often employed in financial sectors and other corporate environments is hardware-based protection, where a tamper-proof physical security […]
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How to disable Network Manager on Linux

Network Manager is a feature-rich network configuration service which is used by default in most Linux desktop environments nowadays. It provides automatic configuration of (wired/wireless) network interfaces, as well as VPN, mobile broadband and even Bluetooth connections. Network Manager is smart enough to automatically switch to the best (or the most recent) connection network, and […]
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How to block network traffic by country on Linux

As a system admin who maintains production Linux servers, there are circumstances where you need to selectively block or allow network traffic based on geographic locations. For example, you are experiencing denial-of-service attacks mostly originating from IP addresses registered with a particular country. In other cases, you want to block SSH logins from unknown foreign […]
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How to enable Software Collections (SCL) on CentOS

Red Hat Enterprise Linux (RHEL) and its community fork, CentOS, offer 10-year life cycle, meaning that each version of RHEL/CentOS is updated with security patches for up to 10 years. While such long life cycle guarantees much needed system compatibility and reliability for enterprise users, a downside is that core applications and run-time environments grow […]
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How to use Mutt email client with encrypted passwords

Mutt is an open-source email client written for Linux/UNIX terminal environment. Together with Alpine, Mutt has the most devoted followers among Linux command-line enthusiasts, and for good reasons. Think of anything you expect from an email client, and Mutt has it: multi-protocol support (e.g., POP3, IMAP and SMTP), S/MIME and PGP/GPG integration, threaded conversation, color […]
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How to back up a WordPress website to remote cloud storage from the Linux command line

Building a website with beautiful design and killer content is a huge undertaking. Compared to the time, money and effort put into crafting a website, people however tend to pay surprisingly little attention to “backing up” the website they have built. It is no-brainer to understand that without a proper backup, you stand to lose […]
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How to access Dropbox from the command line in Linux

Cloud storage is everywhere in today’s multi-device environment, where people want to access content across multiple devices wherever they go. Dropbox is the most widely used cloud storage service thanks to its elegant UI and flawless multi-platform compatibility. The popularity of Dropbox has led to a flurry of official or unofficial Dropbox clients that are […]
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How to send email notifications using Gmail SMTP server on Linux

Suppose you want to configure a Linux app to send out email messages from your server or desktop. The email messages can be part of email newsletters, status updates (e.g., Cachet), monitoring alerts (e.g., Monit), disk events (e.g., RAID mdadm), and so on. While you can set up your own outgoing mail server to deliver […]
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