Linux Notes: Linux Introduction and Caveats

  1. The information presented here is intended for educational use by qualified computer technologists.
  2. The information presented here is provided free of charge, as-is, with no warranty of any kind.
Edit: 2023-09-16



Executive Summary
Every year (since the mid-2000s) I would install some version of Linux on a spare computer just to try it out. In the early years this was usually Fedora but later years was usually CentOS (two distros in the Red Hat ecosystem). I had also played with Debian and SUSE. I'll probably take some flack for saying this but I did not think Linux was worth my time until I played with CentOS-7 which first appeared in 2014. I'm not saying it is better than other Linux distros but I am saying that CentOS-7 made me sit up and take notice. BTW, CentOS is a member of the so-called EL (Enterprise Linux) ecosystem which include: AlamaLinux, EuroLinux, Fedora, Oracle Linux, RHEL, and Rocky Linux.
comment: IBM purchased Red Hat in 2019 to the tune of $34 billion. IBM - Red Hat, a company that starts each project with open source code, announced on 2023-06-21 they were going to restrict access to their source code modifications which could (eventually) affect everything just listed. So you might wish to consider moving to openSUSE Leap. Why? Even though Open Source is an American invention, many American companies do not understand GPL open source as well as European companies (SUSE in headquartered in Germany and their business model more closely follows that of MariaDB Corp).

Linux has been the plaything of academia for a decades which means it is much more feature-rich than proprietary operating systems, but it is not friendly. In fact, it suffers from the problem of "too many chefs in the kitchen".

Caveat: if you decide to enter the Linux world without a paid-up annual support contract then be prepared to support yourself. The self-help blogs are full of people "repeating the same mistakes" or "giving the same bad advice". Many do not appear to me to be seasoned computer professionals. At the very least you should read how Linux is maintained in IBM-managed data centers. You may also want to familiarize yourself with some of my real world Linux problems

A brief history of how Unix spawned Linux


American Politics triggers change

Hard Capitalism vs. Soft Capitalism?

 The concept of opensource software is an American invention (Richard Stallman) so I am surprised when large American try to kill, or sideline, any open-source products they feel are cutting into their profit margins. Here are a few examples of many:

  1. DEC hated both "C" and "Unix" because inexpensive and/or free software was cutting into their software revenue. (they seemed to ignore the fact that mostly PDP and VAX computers ran the internet from 1970 to 1980; they also ignored the fact that this was done using Unix and C)
  2. Microsoft, under Steve Ballmer anyway, always seemed to be at war with competition from the open-source world and yet we learned that Microsoft has been using a lot of Linux servers in their Azure cloud for the past decade
    (this is the same for all cloud-computing providers; no company would be able to afford the per-machine license in a multi-computer cloud)
  3. If you only looked at Oracle Linux then you might think that Oracle fully supports the concept of open-source software, but when Oracle saw MySQL as a potential competitor to their database business, they repeatedly attempted to sideline it (as I have documented here) before acquiring it by purchasing SUN Microsystems. If MariaDB had not been created by forking the MySQL code base then we would be having a very different conversation.
  4. SUSE was founded in 1992 Germany while Red Hat was founded in 1993 USA and they both became successful following the open-source model: give away the software but only charge for support. Both companies did this until 2019 when IBM purchased Red Hat for US$34 billion then began changing things (increased the cost of annual support contracts; now breaking the relationship between RHEL and CentOS; now going to discontinue CentOS after convincing many to move to CentOS back in 2014). Many have suggested that IBM change the name from Red Hat to Blue Hat
  5. I have used both SUSE and openSUSE but they appear to be someone different (internally speaking) than RHEL or CentOS. Developers who want to stay closer to RHEL or CentOS might wish to try one of these alternatives via ELevate leapp
  6. IBM-Red Hat, a company that starts each project with open source code, announced on 2023-06-21 they were going to restrict access to their source code modifications.

The Scottish moral philosopher, Adam Smith, has been called "the father of capitalism" and yet many people do not know that his work was intended to provide the British government with a context on how to redistribute the wealth in order to the support workers who were about to be made redundant by the industrial revolution which was just booting up. While he advocated for what some people might call "soft socialism", American capitalists took things to the next level with hedge funds and the like giving us "hard capitalism". It appears to me that something similar has happened in the open-source world of computer software. While European companies like MariaDB Corporation AB seem quite successful by giving away the software but only charging for support I get the feeling that some American companies would like to put this genie back into the bottle. Of course they would argue that American money built the internet while ignoring the fact that European researchers built the world-wide-web which includes browsers and web servers. SUSE is now an American company whilst openSUSE is still based in Germany. If you do not like the direction American companies are headed then I suggest you check out the European alternatives.


Editing a file on Linux

Many Linux distributions use different commands to do similar things

The only thing common with the various Linux distributions is the name "Linux". For example, numerous Linux distributions use a different tool to partition a hard-disk. For example, check out the following list of commands to initialize then mount a disk under various operating systems

OS Details
Linux In Linux you must do the following (incomplete list):
  • use either fdisk or parted to partition the disk (and know why you would use one over the other; most Linux systems only support one of these commands)
  • use mkfs (then choose one of 50+ volume formats); I prefer mkfs.xfs for most Linux volumes but formats like vfat and NTFS are available for those people requiring compatibility with Windows
  • use xfs_admin to set the volume label
  • use mkdir /mnt/whatever (to create a mount point)
  • use mount /dev/sda3 /mnt/whatever
  • edit /etc/fstab   (to force an automatic mount during the next reboot)
  • caveat: newer Linux distros also support LVM (Logical Volume Manager) which can increase overall confusion.
Note: online help is meant for experts. Type "man mount" or "man umount" to see what I mean.

Initializing then mounting a disk in Windows is mostly automatic

OpenVMS Initializing then mounting a disk in OpenVMS is done in two commands:
  • initialize the disk (struct=2 hails from the days of VAX/VMS):
     initialize/structure=5 disk-name: volume-label
  • mount the disk:
      mount disk-name: volume-label
Note: online help is targeted at non-experts. Type "help initialize" or "help mount" from DCL to see what I mean

comment: For those of us who have worked on systems initially set up by the clueless, perhaps a less friendly software environment is desirable.


Software Updates (support, or lack of it)


Life in a customer-owned, IBM-managed, data center

Hardware is relatively inexpensive in 2018 (compared with systems before y2k) and operating systems like CentOS-7 are free which changes everything. As I understand it, many customer-owned IBM-managed data centers are run like this:

Comparing Linux problems to other operating systems

I have been a VMS system admin and programmer since 1987 then started to work with OpenVMS in 1999. On VMS or OpenVMS, I have always been able to roll back an update. But this appears to be impossible (or at least very difficult) with modern versions of Linux in 2018.




comment: everyone reading this probably knows that software cannot be updated on most computer systems while it is being used. This is not true of OpenVMS where an active process has a run-time lock on some executable (like sys$exe:EDT.EXE;4 in the example above). But if your update is just copying in a newer version of EDT.EXE then it would be saved as EDT.EXE;5. Any process invoking EDT would pick up the new file while current processes could continue to use the old file. I have never seen anything like this on any other operating system. In fact, software engineers at DEC (Digital Equipment Corporation) developed this after running into problems on previous DEC operating systems like RSX-11 and RT-11

Recommended Books

There are so many Linux books available today that it is difficult to recommend any one over another. But for some reason, all the really good computer books in my library are from No Starch Press and it seems the same is true for Linux. These books can be purchased directly from , and

How Linux Works: What Every Superuser Should Know - 2nd Edition (2015) Brian Ward

The Linux Programming Interface (2010) Michael Kerrisk
A Linux and UNIX System Programming Handbook

External Links



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Neil Rieck
Waterloo, Ontario, Canada.