Domain-based Message Authentication, Reporting, and Conformance (DMARC) is a technical specification for email authentication that was developed jointly by the Internet Engineering Task Force (IETF) and DMARC.org. DMARC allows email senders to create DMARC records in DNS that tell receivers what to do if the email being sent doesn’t pass either SPF or DKIM authentication checks.

In this blog post, we will show you how to create DMARC records for your domain using DMARC.org’s free DMARC reporting tool.

Being an expert user or administrator of a Linux operating system environment requires us to have a mastery of Linux file management. Everything under the Linux operating system environment is regarded as a file, from created or existing files and folders to internal or external hardware devices like USB devices.

Linux file management accounts for a larger proportion of the Linux OS operations and starts at a folder/directory level. Linux adheres to a tree-like structure with a base directory that leads to other sub-directories or sub-folders used to maintain created or already-existing files.

In this tutorial, we will show you how to install XAMPP on Ubuntu 22.04 LTS. For those of you who didn’t know, XAMPP is a cross-platform development environment consisting of Apache, MariaDB, and PHP. These are all common components used in web hosting, and combining them into a single installation makes the initial setup less complicated.

This article assumes you have at least basic knowledge of Linux, know how to use the shell, and most importantly, you host your site on your own VPS. The installation is quite simple and assumes you are running in the root account, if not you may need to add ‘sudo‘ to the commands to get root privileges. I will show you the step-by-step installation of the XAMPP on Ubuntu 22.04 (Jammy Jellyfish). You can follow the same instructions for Ubuntu 18.04, 16.04, and any other Debian-based distribution like Linux Mint.

Add the required Swap Space in Ubuntu 22.04 LTS Jammy JellyFish Linux, if you think the existing one is not enough on your Server or Desktop system. Users can also follow this tutorial for Ubuntu 20.04 LTS as well.

Linux (like almost all other operating systems) tries to keep the operating system components, currently required program data, etc. in RAM (main memory), since the access to the RAM is much faster than to data carriers such as hard disk, CD, or USB stick.

However, RAM has its limit of volatile space, if your system has 4GB of memory then it can happen many times your RAM space is allocated completely when we run many programs simultaneously. At this point, the Linux kernel begins to free up RAM by writing parts of the data stored in RAM to the hard disk, the portion of the hard disk that is dedicated to this is called “Swap” memory. If the data is needed again, it is loaded back into RAM and other data that is not needed at the moment is written to the swap. In such a case, it is also said: that “the system swaps”.

With the help of a container and OpenShift's "import from Git" functionality, you can onboard a Rust application onto OpenShift quickly.

In this tutorial you will learn how to enable Gzip compression on Nginx.

Enabling gzip compression is a must because it will not only make your site faster, but it will also save your server's bandwidth from getting used to serve uncompressed content, this means less bandwidth and a faster site served to your visitors.

One of the key aspects of system security is encrypting storage at rest. Without encrypted storage, any time a storage device leaves your presence it can be at risk. The most obvious scenario where this can happen is if a storage device (either just the storage device or the entire system, server, or laptop) is lost or stolen.

However, there are other scenarios that are a concern as well: perhaps you have a storage device fail, and it is replaced under warranty — many times the vendor will ask you to return the original device. If the device was encrypted, it is much less of a concern to return it back to the hardware vendor.

Another concern is anytime your storage device is out of sight there is a risk that the data is copied or cloned off of the device without you even being aware. Again, if the device is encrypted, this is much less of a concern.

Fedora (and other Linux distributions) include the Linux Unified Key Setup (LUKS) functionality to support disk encryption. LUKS is easy to use, and is even integrated as an option in the Fedora Anaconda installer.

The separation means that it looks exactly like a frugal install in the image file. This makes it conceptually very simple for someone to see how to do a frugal install into an internal drive.
EasyOS no longer knows anything about the boot manager or bootloader that caused it to boot. The boot-partition variables BOOT_UUID, BOOT_DEV and BOOT_DIR are no longer in EasyOS. All that Easy knows about is where it is installed, in the working-partition, variables WKG_UUID, WKG_DEV and WKG_DIR.

We all know how running a command in the Debian command line, the Terminal, results in the execution of the command and printing of the results, if any, in the Terminal itself. Sometimes, this immediate display of output is not enough, especially if we want to save the output for later use. Fortunately, the Linux bash and all operating system bash, for that matter, is equipped with the ability to print the output of a command to a specified file. In this article, we will work on the following two scenarios...

Most people expect to see how many log messages are waiting in the disk-buffer from the size of the syslog-ng disk-buffer file.. While it was mostly true for earlier syslog-ng releases, for recent syslog-ng releases (3.34+) the disk-buffer file can stay large even when it is empty. This is a side effect of a recent syslog-ng performance tuning.

Measuring stuff is harder than you may think. Even in math, there is such a thing as non-measurable sets and Banach-Tarski paradox, which shows that a three-dimensional ball of radius 1 can be dissected into 5 parts, which can be magically reassembled to form two balls of radius 1. Now imagine what kind of mess we've got in software engineering.

This may sound somewhat philosophical, so let's get down to earth and talk about BPF programs. BPF, which originally stood for Berkeley Packet Filter, is a general-purpose execution engine that can be used for a variety of purposes, including networking, observability, and security. What we'll be discussing in this article was initially called extended BPF (eBPF) to differentiate from the classic BPF, but now this technology is often referred to as just BPF, and that's what we'll call it here.

Having full visibility throughout the systems we build is a well established best practice. Usually, one knows which metrics to collect, and how and what to profile or instrument to understand why the system exhibits certain levels of performance. But all of this becomes more challenging as soon as the BPF layer is included. Despite years of development, it is still a black box in many ways.

But do not despair: this article will show, with some amount of creativity, that one can reveal what is going on under the hood. The article will begin with a userspace service that uses BPF programs attached to various syscalls to inspect system activity. It does the job, but what we really want is to understand the overhead of the BPF programs themselves. How do you look inside? That's the problem that we will ultimately tackle.