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Linux or Unix: Pros and cons

If you're in need of a reliable, scalable environment, Linux or Unix may be the answer. Discover the pros and cons of each and figure out which is the best fit for your needs.

So, Windows is no longer cutting the mustard and you need a more scalable, reliable and higher performing environment. You may be running Oracle Financials, PeopleSoft or any of a number of ERP applications. Or you may be looking to deploy a new Web portal with something like IBM WebSphere with a DB2 backend or WebLogic and Oracle.

In years past, you would have purchased one of the big-three Unix manufacturer boxes (IBM, Sun or HP) and that would have been the end of it. But these days, Linux is also a perfectly viable option worthy of consideration. How can you evaluate which one is right for your company? In this article, we'll discuss the pros and cons of Unix vs. Linux, and hopefully provide you with some decision criteria.


  • Hardware support and integration

    Unlike Linux, Unix is typically packaged with vendor hardware. Because it is so closely tied to the hardware, Unix offers all sorts of performance and reliability advantages because the operating system has been optimized for a specific hardware platform.

  • OS support and reliability

    Patch management, fixes and maintenance-level upgrades are all handled by the manufacturer of your Unix. You need not browse the Web to find the appropriate fix for your problem. On many occasions, phone support will direct you to the fix and even walk you through the installation. The operating system is supported by your vendor 24x7. When your box crashes (and every box crashes), there is always someone to call.

  • Comfort level

    If you prefer working with a company that can hold your hand through all types of problems, Unix is definitely the answer for you. With Linux, you are definitely more on your own, even if you purchase a Linux distribution that is supported by one of the big three Unix vendors. 24x7 vendor support is not uncommon in Unix environments.

    Although some of the Linux variants are starting to do better, any informal poll by administrators will tell you that companies such as Red Hat still have a long way to go in comparison to supported Unix platforms.

    On the hardware side, your sales account team will always be a resource for you, as will the business partner that may have sold you the product. If something breaks, you can always find someone to scream at.

Here are some of the downsides of Unix:

  • Flexibility

    Ever try to suggest to a Unix vendor that they should incorporate x,y and z into their kernel to fix a specific problem or add value to their OS? My guess is no, because that is just not likely to happen. In the Linux world, you actually have the source to the kernel, and if you have the knowledge, you can actually make the changes yourself!

  • Price

    You will pay a premium to the Unix vendor to buy their proprietary Unix, as opposed to Linux. The cost is not so much the price of the license, but everything else that comes with the package. That includes maintenance agreements, software licenses, hardware that is much more expensive, overhead costs to the marketing folks, etc.

  • Market share

    While market share is increasing for Linux and even Windows, it is decreasing for Unix systems. While I'm certainly not going to suggest that the death of Unix is eminent (we all remember the BYTE magazine prediction of the 90s), it is definitely not in its growth stage either. The end-of-life is certainly nearer for Unix then Linux, which has only started to reach its height of innovation.

  • Divorce difficulties

    When you decide you want to go with AIX for your Unix, you are married to IBM. That includes the hardware, the support, the maintenance and their sales people and/or business partners. I'm not suggesting that is always a bad thing, as IBM is very strong in all areas, but you are married to that vendor. With Linux, you are not married to any vendor. Although there are many Linux distributions, the kernel is essentially the same.

  • Support

    Unix administrators are much more expensive to have on your IT staff then either Windows or Linux administrators. One must consider all costs when migrating to a new environment.

Unix has been around since 1969. It's a mature operating system. It is supported by all ISVs and also has hardware support from companies like IBM, HP and Sun. The major Unix flavors, AIX, HP-UX and Solaris, while all different in many ways, all are mature, stable and scaleable. The top reasons for going with Unix are:


Although Linux does not have the storied history of Unix, it has been around for almost 14 years. In many ways, Linux is nothing less then a Unix variant. For those of you familiar with recent litigation, SCO will tell you it actually is Unix.

Created by Linus Torvalds, a student and one time hacker, Linux evolved from Minux though the GNU Project (GNU is Not Unix) in 1984. It was formally released in 1994, licensed by the GPL. Unlike proprietary Unix systems, each of which are maintained by proprietary hardware manufacturers, Linux is maintained through the help of a community of thousands of developers all over the world; writing, testing and enhancing code.

While Linus continues to function as the caretaker of the Linux kernel, several Linux distributions control the high end market that sell to the corporate world. By far, the two top variants are Red Hat and Novell's SUSE.

Here are some of the key points in favor of Linux:

  • True open systems

    Perhaps the biggest selling point with Linux is that it gives you choices. From hardware to support to Linux distribution, you have a multitude of choices to make. You can run Linux on a $200 used PC, you can run it as an LPAR (logical partition) on a million-dollar p595 IBM pSeries server (you must make the choice between RHEL4 or SLES9) or you can even run it on an IBM mainframe.

    With Linux, you are no longer held hostage to the whims of your hardware distributor. Though Unix is marketed as an open system, the reality is that you are usually married to the hardware vendor. Linux is truly an open system.

  • Bug fixes and security patches

    Ever had to wait weeks on end for the latest fix-pack or security patch to come out from your vendor to fix an OS bug? With Linux, you might wait days or even hours. The open source community can deliver with lightning speed what takes endless development cycles to be released using traditional channels.

  • Increasing resources

    Every major ISV today has or is coming out with a Linux version of their software. Linux market share is on the upswing and people are asking for it. At the same time, more administrators are getting trained on Linux and a wealth of public information is readily available to help companies during a transition to Linux. Unquestionably, more innovation is coming to Linux then Unix.

Here are some of the downsides of Linux:

  • Scalability

    With the advent of the 2.6 kernel, scalability has certainly become much less of an issue then ever before, but Linux still cannot scale as much as Unix. For the enterprise that requires maximum performance, reliability and scalability, Unix is still the better choice. High availability is also much more mature on Unix then Linux.

  • Lack of hardware integration/support

    Though many will see this as a plus, Fortune 500 companies typically like the comfort ability factor that comes with hardware support and tight integration between the hardware and the OS. We all know about finger-pointing and what can happen when your hardware vendor is different from your operating systems software vendor. Driver support is a given for hardware vendors, but is always a challenge with Linux.

  • Perception

    Anyone that has tried to convince his CIO to replace Unix with a Linux server understands this question. Linux is unfortunately still perceived in many circles as risky and not enterprise ready. Many CIOs are set in their ways and not ready to take chances with 'bleeding edge' solutions, even ones that we all know are not really bleeding edge. This perception of Linux has changed considerably over the past several years, but it's still there in the larger companies.

Having used Unix and Linux in a corporate environment, I can tell you choosing between the two operating systems is never an easy task. The decision usually comes down to money and what people are most comfortable with. We will get more into the details in subsequent articles in our series.

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