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Community Enterprise OS Linux System Setup and Product Review

About three years ago I used Virt Manager installed in Feren Linux to create a Virtual Machine of CentOS 8 Linux based on RHEL 8 from Red Hat and then conducted a system setup and product review of this distro on my YouTube Channel called the Linux/Unix/Tech channel.

Basic Centos 8 Firewall Configuration

The firewall is a vital component of any Linux distribution. This is even more important when running a server versus a desktop distro. Firewalls are necessary since they protect a computer system or a network of computers from an external attack especially in a server environment where the server is connected to the Internet in an always-on Internet connection.

Benchmarking a Storage Device in Linux

There are a couple of CLI tools that can be used to benchmark an HDD (external or internal). These are dd and hdparm. However, for Debian Linux, there’s a great GUI application that performs Disk Read speed benchmarking and both Disk Read & Write speed benchmarking if the drive being tested is unmounted. The dd command is used to monitor the writing performance of a disk device on a Linux and Unix-like system. An example for testing an internal SSD would be: 

$ sudo dd bs=1M count=256 if=/dev/zero of=test 

Converting Ubuntu 20.04 LTS to Vanilla Gnome3 DE

By default, Ubuntu 20.04 LTS is developed with a highly customized Gnome3 desktop which looks very much like the original Unity desktop. Many people, including myself, do not like the look and feel of this desktop even though it is based on the Gnome3 desktop environment. I am assuming that you are familiar with both Linux, the Linux Terminal, and have used Ubuntu Linux in the past. If you don’t meet these prerequisites, then you may find some of the steps in this conversion process to be a little confusing.

Creating Docker-Compose Applications

Docker Containerization in Linux

The concept of docker containerization in Linux is very similar to the concept of virtualization. Using virtualization in Linux is accomplished through the use of a hypervisor, such as VMWare, Virtual Box, or Virtual Machine Manager. Virtualization allows one to run small Virtual Machines (VMs) on one server platform and they each exhibit the functionality and performance of physical servers, yet are virtual. Containers are not actual servers; that is to say, not in the same way one would typically think of servers.

Basic File and Folder Permissions in Linux

Linux handles file and folder permissions differently than operating systems like Microsoft Windows. Unlike file and folder permissions in the Windows world, Linux does not have what Microsoft Windows refers to as “effective” permissions on files and folders. True, one can change basic permissions on file objects in Linux using Access Control Lists (ACLs) or more appropriately File Access Control Lists (FACLs), but the point of this article is to introduce the new Linux user to the basic file and folder permissions that Linux uses when these objects are created in the system.

Bash Directory Stack

What is a stack and why is it important in Linux or Computer Science, for that matter? A stack, in the context of this article, refers to a last-in-first-out (LIFO) list or more affectionately referred to as a pushdown store. This is in contrast to another arrangement called first-in-first-out (FIFO) used in granaries since the grain is loaded at the top of the tower and dispensed at the bottom into trucks or other vehicles for delivery to its destination.

Designating Hot Spares in Your ZFS Storage Pool

There is a feature built into ZFS called the “hotspares” feature which allows a sysadmin to identify those drives available as spares which can be swapped out in the event of a drive failure in a storage pool. If an appropriate flag is set in the feature, the “hot spare” drive can even be swapped automatically to replace the failed drive. Or, alternatively, a spare drive can be swapped manually if the sysadmin detects a failing drive that is reported as irreparable. 

Hot spares can be designated in the ZFS storage pool in two separate ways: 

Allowing SSH Into Two Separate Ports, One For LAN and One For WAN

Is it possible to configure a server such that one can ssh into that server internally on a LAN while being able to ssh into the network interface that communicates on the WAN out to the Internet? How do we handle this? Do we just open port 22 for ssh for both LAN and WAN and call it a day? Is this going to pose a security risk by allowing port 22 traffic from the WAN internally to our LAN? Can we even do this? The answer to this question is, YES! How can we take care of this without posing an unnecessary risk on our server? The answer to this second question is simple.