Softpanorama (slightly skeptical) Open Source Software Educational Society

May the source be with you, but remember the KISS principle ;-)

Solaris vs. Linux: Framework for the Comparison

by Dr Nikolai Bezroukov

2. Nine factors framework for comparison of  two flavors of Unix in a large enterprise environment

I developed the framework presented below for the comparison of Solaris and linux. But it is a quite general framework that can be adapted for comparison of any two Unix flavor in large enterprise environment.

While there are many similarities, there are also several important differences between large enterprises and small enterprises environments.

• The key difference is that large enterprises usually already have huge investments in one or several of major Unix flavors like AIX, HP-UX and Solaris and thus inevitably incur huge costs of transitions independently of merits or demerits of the new OS that is introduced into the pre-existing mix of Unix flavors. 

• The second important difference is that in a large enterprise  several classes of servers usually are present: small medium range and large while in small enterprises either the whole infrastructure is built on small servers (sometimes there are a couple of midrange severs in the backbone.)
   

• Scalability issues usually are more acute in large enterprise with its almost endless stream of acquisitions and divestitures.  The size of the company can double in one year due to a large acquisition and this possibility should be taken into account when planning IT infrastructure.
   

• Also due to large investment ion particular set of flavors of Unix is accompanied by large investment into sysadmins that serve those servers. While not necessary better paid then their counterparts in smaller enterprises, sysadmins employed by large enterprises usually have better access to vendor training and support then sysadmins from medium or smaller enterprises. Also staff tends to be older with more years of administration under the belt. It is not uncommon to see people who have more then ten years of system administration under the belt. Both factors create more resistance to change.

Of course there are exceptions to this picture but generally I think those three distinctive features are pretty typical. 

The complexity of the modern OSes creates some kind of natiral limit of the level of adoption and typically enterprises prefer one flavour Unix over another. At the same time one other major flavour typicallly exist as a result of mergers at least in minor qualtities.

This makes the issues of proliferation of Unix flavors really important for any highly qualified system administrator who have multi-year investment in particular (favorite) flavor of OSes and rather good but less in-depth understanding of some other commercial flavor. Moreover if the organization have three of more flavors of Unix sysadmin naturally tend to limit themselves to one major and one minor flavor, ignoring everything else. That means that there can se some specialization in the Unix group in enterprises that have three flavors of Unix.  This natural tendency is probably connected with the limits of human capabilities to understand such complex systems as modern OSes: you cannot implant the second head to system administrator and it looks like there is only a space for just two OSes in a regular heads :-). 

To quote  Linux Torvalds, changing operating systems for sysadmins is not unlike “performing brain surgery on yourself”.  And the more qualified sysadmin is in particular brand of Unix, the more he/she tend to lose from switching.  For the next year or two  he/she will feel himself like a novice on the skating ring, not very comfortable felling...

Another factor is that administration is usually more formalized and governed by some procedures which are connected either with legal issues or with the security. For example SecurID tokens are most common in large companies. Also some integration with Windows infrastructure, especially the ability to use Active Directory for identity management of Unix users tend to be important (and more common) for huge companies with many thousand of PC clients and diverse team of system administrators geographically dispersed in several sites

I would suggest the following  factors represent the most important differences between large enterprise and small enterprise (and non-enterprise) environments. This list definitely can be extended, but even in the current form it might provide a useful framework for the understanding the cost of introduction of a new flavor of Unix in enterprise environment. We will distinguish the following nine major areas of comparison of challenger and incumbent.  they are subjectively rated in the decreasing order of importance

We will postpone discussion of two  issues until later

1. Good fit with major deployment areas (will be discussed later)

2. Security issues (will be discussed later)

and discuss the following six areas:

1. Unix ecosystem-related issues

2. The cost of patching

3. The cost of support

4. The level of scalability
5. Know-how costs

6. Dangers inherent in development and business models

7. Uncharted issues in intellectual property law

Created Jan 2, 2005.  Last modified: February 28, 2008