The Linux System Administrator
My first encounter with Unix like command environment was in college computer lab. I was awestruck by a completely different way of using computers, but it was 6 years later that I became fully fledged Unix / Linux user. My first laptop crashed due to overhitting and coincidently, just 2 months later I was inducted into a project where the ETL jobs were scheduled on a proprietary Unix system. I was able to use my laptop only in windows recovery mode and hence I got an idea to run a lightweight 32bit Ubuntu on my laptop. This was a game changer for me, not only I loved Ubuntu, but I also got a free terminal to practice Linux commands, VIM etc. which was directly beneficial to me in my work, Fast forward to today, I have a Dell G15 (32 GB RAM and 20 Threads Processor) running Ubuntu, while my old HP laptop (8GB RAM and 4 Thread Processor) is running Arch Linux.
I opted for and cleared the certification examination of Red Hat Certified System Administrator, in order to understand my laptop deeper which alleviated any fear of unstable system though to be honest, Linux is the most stable operating system. Our internet works on Linux System (remember the web links have forward slash, eg. amazon.in/gp/css/order-history); Android uses Linux kernel; Super Computers run Linux – All Hail Linux – need I go any further.
The Secure System
I am running, Arch Linux in my laptop and I have hosted it like a personal server which I can connect to from office or travel, to maybe run Apache Spark or something else. I don’t have a static IP, I just check my public IP to connect to my server, and I have opened port forwarding (22 on my Network to 22 on my Arch Linux), I didn’t know this, but it’s pretty insecure since 22 is a well-known SSH port, hence there were tens of attempt daily to hack onto my arch Linux which I got to know recently. I analyzed my logs and evidently there was zero success on my system. Despite thousands of attempts over six months, no one could hack into my system, all thanks to the default configuration of SSH-Server. I have made it more secure now and even changed the port mapping and since then there has been zero attempt, yet I am so proud that my system in its default state was able to fend of all attacks.
The Objective of this Series
While I was preparing for RHCSA exam, I realized that a lot of learning material for Linux is closely guarded which is a direct contradiction of Open Principal, Linux follows. Additionally, I felt bad that people teaching Linux are not running Linux themselves. Hence, I not only want to teach Linux but also wants to inspire folks to adopt Linux (unless they are using MAC), and a biproduct of these teachings can be a successful attempt to Red Hat or other system administration examinations.
The Course Outline
- Basic Linux Commands.
- Linux Utility Commands.
- File Management.
- Process Management.
- Storage Management.
- Software Management.
Installing Linux
While there are many flavors of Linux available, the top two option I would suggest for beginners are:
1. Ubuntu
Ubuntu by canonical is designed for easy installation and desktop usage. Additionally, you get free Pro Subscription which entitled you to get support in case of issue. Download the installable ISO from Download Ubuntu Desktop | Ubuntu.
2. Red Hat Enterprise Linux
Red hat is widely used and hence you get a lot of software’s through Red Hat repos. You need to register your RHEL to download software’s through dnf command. Get your installable from Red Hat Developers | Red Hat Developer site after registering.
Installation General Steps
- Get hold of a bootable USB device, through apps like Rufus. On a linux machine, you can do the same yourself using dd command
dd if=/path_to/osfile.iso of=/dev/sdx bs=4M
where /dev/sdx is the USB device name, can be looked up by lsblk command (I am going to cover this later), but my point here is, you don’t need anything external as the tool is built into your linux system and it goes for a lot of things. - Ensure that secure boot is off then go to boot menu (usually pressing esc, f9, f11 or f12 works, check online for your own computer), and boot through the USB device created in step one.
- The bootable USB device starts a Linux System, which also installs Linux on the computer HDD/SSD. Installer programs are fairly straightforward, and it may take some time (up to 20-30 minutes for the installation to finish). Once installation is done, the installer will ask you to remove the boot device and restart. Once you do that, Linux Kernel will be loaded from your computer’s hard drive (or SSD).
- Boot sequence is something you may have to check if you don’t see your Linux loading. It can be accessed through the same boot menu and ensure that your Linux is on top of that so that it automatically loads, it is something to note though, likely it won’t be an issue.
- Finally, there are tons of videos online, check it out for installation process to ensure that you are following the instruction correctly. Don’t forget to Back up your data, because installation will wipe out your disk clean.
Final Thoughts
Stick with me, I will try to do my best teaching and recording the sessions. I will run the commands on Bare Matel Ubuntu Instance or a Virtual RHEL instance. I won’t cover any Unix specific concept since my focus is on Linux.
I am also not going to start a history session however if you feel like you need to know a bit about Linux origin story, the following video is one of the best on YouTube:
https://youtu.be/obJOwEy62bk?si=81S26Pn5kiVBKQRI
I think we are all set for the next blog where I deep dive into the Linux Terminal.
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