What Does Unix-Like Mean

What Does “Unix-Like” Mean?

There is so much tech terminology and so little time – so it helps quite a bit when we can think of things within categories. In the case of operating systems, there are essentially two. There are the ones from Microsoft, descendants of Windows NT (for “new technology”). On the other side are basically the remainder of options. These other systems – such as Chrome OS, Orbis OS, iOS, Mac OS X, Android, and Linux – all have a code structure that is loosely described as “Unix-like.”

 

UNIX & its many offspring

 

We can start to understand the term Unix-like by looking at Unix construction and the operating systems created with it as their basis. Coders at Bell Labs, an AT&T facility, created Unix in 1969; Ken Thompson is the specific person credited with its development by the Linux Information Project.

 

Many technologists and organizations have developed operating systems from Unix over the years. However, there are generally two branches of Unix’s “next of kin.”

 

One branch was within education. The chief example is the Unix-like, open source OS Berkeley Software Distribution (BSD). This system is built into such further offshoots as FreeBSD, NetBSD, and OpenBSD. In fact, BSD was used to create NeXTStep, which was in turn used to design Mac OS X (from which iOS was developed). In fact, the operating system of the PlayStation 4, Orbis OS, was coded with BSD as its foundation.

 

The GNU project, an effort launched by Richard Stallman to aid in making licensing terms loose enough to facilitate free use of programs, was inspired by the tightening of language within AT&T’s Unix agreement. MINIX was a Unix-like system that was intended for use within academia, and Linux is a descendant of MINIX. When we use a Linux OX now, we are actually using GNU/Linux, notes Chris Hoffman in How-To Geek – because these systems combine a Linux kernel with numerous GNU utilities.

 

GNU/Linux (otherwise, and commonly known simple as Linux) is not a straight offshoot of BSD. However, it is similar because it uses Unix as its initial structure and also grew out of scholarly circles. Many different operating systems – notably Android, Steam OS, and Chrome OS but also ones used on many devices – are rooted in Linux.

 

The above systems were all a single side of development from the original code, the educational offshoots. The other side was commercial systems that were created, with many different companies wanting to promote their own version. These systems are now much less prevalent, but they have included AT&T UNIX, HP-UX, IBM-AIX, SCO UnixWare, SGI IRIX, and Solaris.

 

What do we mean by “Unix-like”?

 

What does the term Unix-like mean specifically, though? It is a blanket way to refer to many different operating systems that all share the same common structure – as opposed to the one used by Microsoft. Unix-like also grew from confusion and debate over what should be considered a Unix system.

 

When we call an OS “Unix-like,” that generally will mean that the source code of the OS (the version of the software as it was originally coded) is directly traceable to, has similar properties to, and is explicitly based on Unix. Examples are Compaq’s True64, Solaris, IRIX, HP-UX, and IBM’s AIX.

 

The umbrella-term Unix-like also refers to clones of Unix. A clone is software that performs in a similar way to other software but does not have the same source code.

 

The way that the prominent Unix clones act is so, well, er, Unix-like that often computer scientists and expert technicians simply refer to them as Unix. These systems should be understood as clones, though, and not Unix-based but certainly Unix-like. These clones include the BSDs (Darwin, FreeBSD, NetBSD, OpenBSD) Linux (in all its distros), MINIX, Cygwin, and QNX.

 

For the most part, a Unlike-like OS will have most of the additions and elaborations that were appended to the original at the University of California – Berkeley. These features, often called the Berkeley extensions, contains the vi text editor, virtual memory (enabling simulations of extra memory by the hard disk drive), transmission control protocol / internet protocol (TCP/IP, the primary protocol for the internet and local networking), and C shell (csh). Since these capabilities from the Berkeley extensions are so core to the functioning of Unix-like systems, people have sometimes posited that modern systems of this type should be called “Unix/Berkeley” (or “Unix-Berkeley-like”?).

 

Now let’s look at BSD directly: this OS, short for Berkeley Software Distribution, is a Unix clone that was written at the University of California in the 70s and early 80s. Generally BSD and its offshoots are called Unix; actually, one version was even called BSD UNIX 4.0 (October 1980).

 

Controversy related to the UNIX name

 

UNIX is the initial name of the operating system that was created at Bell Labs – that part we know and is indisputable. The way that the term has been understood since that point has become much fuzzier. UNIX became a trademark, and an association created in 1996, called the Open Group, eventually acquired ownership of it. The Open Group states that operating systems should only be called UNIX if they agree with the body’s Single UNIX Specification and pay them a sizable fee. In this sense, it is possible that a system could be called UNIX legally even if were dissimilar to the original and did not contain any of its source code.

 

Apple has questioned the legitimacy of the UNIX trademark – claiming that the term is generic and should not be protected by the government. Apple actually has stated on its website, “Beneath the surface of Mac OS X lies an industrial-strength UNIX foundation.”

The Open Group and Apple have been sparring over usage in this manner.

 

A couple key UNIX or Unix-like characteristics

 

Key design characteristics of the original version of Unix are shared by today’s modern operating systems.

 

One of the basic centerpieces of the way Unix is constructed is that you have small utilities that are fine-tuned to perform single tasks. When you interact with the OS, you are able to leverage these tools in part by blending them, via pipes or otherwise, to carry out more sophisticated activities. By elaborating on modules in this manner and combining utilities, shell scripts also become simpler.

 

Another aspect of Unix that makes it special is that there is just one file system through which software is able to exchange data and interact. All components of the computing ecosystem become represented by files within this model – including special files with system details and even hardware. The contrast to this architecture is the drive letters of Windows (C, D, etc.), a format that Microsoft brought over from DOS. In contrast to breaking everything up into drives, there is one unified directory hierarchy on Unix.

 

What does it mean to have full root access?

 

You will sometimes hear coders and others discussing infrastructure talk about full root access. Full root access means that you have complete superuser privileges over your system – administrative-level control. The root user is unique to Linux and other Unix-like operating systems.

 

Do you want super-fast performance and root access? At KnownHost, our managed VPS hosting plans come with full root access for complete control. Compare plans.

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Open Source Hosting

The Open Source Technology That Powers Your Hosting Solution

When it comes to the technology that powers your business, there are generally two prevailing attitudes about it: 1. I have specific demands and I’d like to know what each piece of software is that’s keeping my website online. 2. I don’t particularly care what the software is, I just want the website to work with minimal headaches. Both of these attitudes are valid, but even if you’re in the second camp, it’s important to know what software is being used to power your website.

 

There are a lot of moving parts when it comes to taking your site from a bunch of files sitting on a local computer to a website that’s making you a lot of money. Whether you’re working with a managed VPS or a dedicated server, you need to know your way around even if you’re going to delegate much of the web work to another member of your team.

 

Many hosting environments are powered by Linux, which is an open source base for many different operating systems. You can also find Windows hosting if you’re running proprietary software that requires Windows. Otherwise, Linux is your best bet when it comes to flexibility. Granted, not every specific piece of software that makes up your development environment is open source in and of itself, but many are.

 

Regardless of its truly open source status, each piece of software works together to create the environment you and your team will be working with every day. Some software allows customization and in many categories you have choices when it comes to which solution to go with. Let’s take a look at the OS on the server itself, what control panels you can use to make changes, and what content management system you may want to install in order to generate your user facing content.

 

Linux Server

 

The base of your server, the operating system, is some flavor of Linux which is an open source technology at the kernel level. However, there are some proprietary Linux variants that may be of use to you that aren’t open sourced.

 

CentOS

 

Red Hat is the name in enterprise level Linux, however CentOS is the popular and free, open source variant that has become the backbone of many development environments over the last decade or so. That’s because it has matured into a simple, no-frills stable OS that comes with some helpful security featured baked in. Its most attractive quality is the fact that the development cycle isn’t too rigorous and it is developed in such a way to reduce the risk of crashes and errors.

 

CloudLinux

 

If you’re running a dedicated server with the plan to resell space on it to a multitude of clients, CloudLinux may be of interest to you. This operating system allows you to better divide the space of a dedicated server to “rent” out to clients in a shared hosting arrangement while reducing the chances of one site’s resource usage greatly affecting the resource pool of other sites on the server.

 

Control Panels

 

Many of the most popular control panels aren’t open source in and of themselves, but your host will provide them for you and they are compatible with a Linux environment.

 

cPanel/WHM

 

Easily the most popular control panel, cPanel and WHM are offered by practically every hosting company as an option. WHM is used to generate user accounts that can then be given cPanel logins. Again, this is ideal for a hosting reseller situation where you’re dividing up server space amongst other clients. cPanel itself is where you’ll be doing a lot of the big picture work. You can install your content management system here, alter code, manage email accounts on the server, access FTP, and more. cPanel is flexible and relatively easy to get the hang of so it’s often the default choice in a Linux environment because it is designed with CentOS, Red Hat, and CloudLinux specifically in mind.

 

Plesk

 

Right off the bat, if you’re running a Windows server, you’d be using Plesk (or something else) instead of cPanel because Plesk has Windows compatibility while cPanel is Linux only. However, if you’re on a Linux server (and at KnownHost you would be using Linux) you have a choice. Plesk is seen by some as easier to understand, though this is a matter of preference. Some believe Plesk on Linux isn’t quite as useful as it is for Windows, but your mileage may vary.

 

Content Management System

 

You may not think about your operating system daily and if you’re not a developer you probably won’t even be in your control panel terribly often. But, what you will be using every single day is your content management system. Each of the following content management systems is open source and is great for different reasons.

 

WordPress

 

Over a quarter of the web runs on WordPress, so as far as documentation and developer resources are concerned, the possibilities are endless. WordPress powers many major sites and has evolved to include nearly any kind of functionality. However, it’s the ideal platform for informational based sites. If you’re planning on launching an ecommerce site, you’re better off with a CMS designed for it specifically such as…

 

Magento

 

Magento is the big name in ecommerce CMSes, especially large-scale sites. The learning curve is on the steeper side, and unlike some of the other CMSes, WordPress in particular, you’re going to need a developer on hand to do a lot of the heavy lifting when you need certain types of functionality. Once it’s configured to your liking, though, it becomes clear why so many large retailers rely on Magento.

 

Joomla

 

As far as difficulty of use is concerned, Joomla probably sits somewhere between WordPress and the CMS that will round off this list next. If you need more flexibility and power than what WordPress offers, Joomla is a popular choice. It’s not too technical, but you can certainly go into the weeds if you are so inclined. This flexibility means you don’t necessarily need to be calling your developer all the time. Joomla is great at ecommerce, though it isn’t designed exclusively for it like Magento is. Interestingly, if you’re looking to develop your own social network, Joomla is the best of the bunch to use in order to accomplish that.

 

Drupal

 

Drupal is arguably the most powerful CMS on the list. But, that power comes with a trade-off. The trade-off is accessibility. You’ll need to understand HTML, CSS, and PHP to get anywhere with Drupal, making it the ideal choice for the hybrid developer-business owner or the business with a dedicated Drupal developer on staff. If you have the personnel resources, you can make Drupal do nearly anything you want. Whether you want to develop a website, a store, a social network, or an online application, you can make Drupal work for you.

 

Conclusion

 

Your hosting environment is made up of many parts. They all provide different functionality that makes up your VPS or dedicated server. While you personally may not spend much time tinkering in the backend of your site, someone on your team probably will be. At KnownHost, we’re dedicated to providing you with the customer service you need when you need it. Contact us today to find out more about how we can help your web presence grow.

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What is CentOS, and Why Should You Care?

  • Being Linus Torvalds
  • The story of Linux
  • Things you wanted to know about CentOS but were afraid to ask

CentOS is a particular distribution (aka distro) of the Linux operating system. Let’s look at Linux first to get a sense of that general technology and community, then take a direct look at this particular variation of the open source operating system.

Being Linus Torvalds

Like many major moments in computing or any field, when Linux was introduced, it didn’t seem like that big a deal until years later. On August 25, 1991, Linus Torvalds wrote a simple post in the Usenet newsgroup comp.os.minix. “I’m doing a (free) operating system (just a hobby, won’t be big and professional like gnu) for 386(486) AT clones,” he wrote in part. “This has been brewing since april, and is starting to get ready.” [sic]

The free OS that Linus was casually announcing would end up becoming a major piece of computing networks worldwide. Suffice it to say that today, Linux is not just a single developer’s hobby.

As the operating system began to take the world by storm, Glyn Moody of Ars Technica became interested in the steps that preceded its initial release. He flew to Helsinski, Finland, in December 1996 to speak with Torvalds at his home, resulting in the story detailed below.

The story of Linux

Linus started attending Helsinki University in 1988, where he was working on a degree in computer science. In 1990, he became familiar with the Unix operating system in one of his classes. The course he took had a cap of 16 students because that was the capacity of the school’s license. Torvalds was immediately drawn to the operating system, feeling that its coding interface was surprisingly user-friendly.

One of the textbooks for the class was Operating Systems: Design and Implementation. The book included source code for the OS Minix, which had become available on the Intel 80386 processor. Linus was very interested in chips and thought the 80386 was the best he had seen from the company.

It sparked a technological leap, in part because he had money from student loans and Christmas. “That’s when I actually broke down,” Torvalds told Moody. “I remember the first non-holiday day of the New Year I went to buy a PC.”

Linus bought his PC in January 1991. However, he couldn’t work with Unix because he didn’t yet have the Minix floppy disks. While he waited, he played Prince of Persia and started running tests on the 80386 chip.

He wanted to know how effectively the computer chip could switch from one process to another. He would run two tasks, with a timer set to alternate between them. One task simply wrote the letter A, while the other wrote the letter B. He was not programming very much at that point because he was getting to know the parameters of the Intel CPU.

As bizarre as it may sound, the bare-bones task-alternating project eventually morphed into the Linux kernel. Torvalds realized that he could change the A and B tasks to emulate a terminal. He had one task that was moving information from a keyboard to a modem, while another one brought data from the modem to the monitor.

“I had keyboard drivers because I obviously needed some way to communicate with this thing I was writing,” Linus explained, “and I had driver for text mode VGA and I wrote a driver for the serial line so that I could phone up the University and read news.” In other words, he was simply gathering information from newsgroups via the modem.

An advantage of drawing from the newsgroups was that the comments therein helped the young programmer to revise and strengthen the developing OS throughout the summer of 1991. Linus also realized he wanted to be able to download, so he programmed a disk driver. He additionally had to create a file system that could draw from the Minix file system for writing and reading during upload and download. Unix is essentially composed of these basic components, Torvalds noted: alternating between processes, drivers for your devices, and the file system.

Linux received its name by accident, really. Linus needed to know the POSIX standards that made systems similar to Unix compatible with one another. These specifications were a bit expensive, according to a professor at the university, Ari Lemmke. However, Lemmke said he was actually focused on operating systems and kernels himself.

“He had this small area on [the FTP server] ftp.funet.fi, and he said: ‘[H]ey, I’m putting a directory aside for you,” said Torvalds. “So he created the /pub/os/linux directory.”

Linux was the name Linus had given the project while it was in initial development, but he never intended for that to be the name of the OS when it was released publicly. He feared people would think he was arrogant. He wanted to instead called it Freax for Free Unix. Lemmke saved it instead under the work-in-progress name Linux, and it simply moved forward under that heading.

The first version of the OS was released via email to some contacts from the newsgroups. Torvalds rushed that version to get something up on the FTP site to which he had access. The next version, which he announced via the Minix newsgroups, represented a vast improvement.

Still, the original base of users was miniscule. “I don’t know how many people got [this first public version in comp.os.minix],” Linus commented. “[P]robably 10, 20, this kind of size.”

Things you wanted to know about CentOS but were afraid to ask

Now let’s look down the line at CentOS, one of the most prominent offspring of Linux.

Known for its stability, consistency, easy-to-use administration, and straightforward replication, this flavor of the open source OS was created as a spinoff of Red Hat Enterprise Linux (RHEL).

Beyond the OS itself, the CentOS Project – the entity that manages development of the platform – serves an organizational role by providing resources so that other groups can more easily develop tools based on the CentOS system.

CentOS, which was first announced in March 2004, is community-developed, based on source code released at no cost by Red Hat. Part of its grounding is that it should maintain compatibility with RHEL. The OS is free to download, use, and make available to others.

The community consists of a core development team and users ranging from casual Linux fans to corporate system administrators.

The basic idea behind the CentOS Project is to give people a strong system for open source groups to use and extend. The framework can be utilized by hosting companies and for processing of scientific data, for instance. Organizations are able to place their programs on a reliable platform.

The CentOS Governing Board consists of original project members and Red Hat personnel, all of whom help with development of the ecosystem.

The Project was designed in a similar manner to the esteemed Apache Foundation. “A governing board… oversees various semi-autonomous Special Interest Groups or SIGs,” notes the CentOS site. “These groups are focused on providing various enhancements, addons, or replacements for core CentOS Linux functionality.”

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