Despite the number of data centers I have seen so far, I have yet to find one that could operate entirely without Unix while still maintaining its levels of functionality, efficiency and reliability.Since my first semester at University I use Unix and since 1992 I operate it myself.
Besides the Unixes most commonly used today, like Solaris, Linux and the BSDs, over the years I have also become familiar with AIX, HP-UX, Digital Unix (now called Tru64), Irix, Nextstep/OpenStep and even SCO OpenServer and Unixware.
My hardware experience ranges from the 150 € embedded system up to the SUN E10000s and IBM SP/2s of the dotcom era.
I am particularly enthusiastic about heterogeneous environments that combine e.g. Linux on low cost PC servers with Solaris on large SPARC-based systems. In my opinion there is frequently no other way to simultaneously achieve similar degrees of efficiency and flexibility.
First introducing Unix in a pre-existing environment can be a daunting task.
I advise my customers how to deal with the initial problems they may encounter and how to put all the features of Unix to use in an incremental way that matches their needs and desires.
Advancing Existing Environments
Unix keeps evolving. Some vendors go out of business—in one particularly spectacular case by suing its own (ex-)customers—while others keep surprising with ever exciting new features, run on particularly efficient or low cost hardware, or offer clever approaches to lowering overall IT costs.
As an independent freelancer I help my customers to make the most of the new developments when they become available.
Through the years I have held a variety of Unix-related talks, written some documentation and code. At least some of them are available online.
For several years I have been an active member of the German Unix User Group (GUUG). It is the most prominent organization of professionals interested in the use of Unix in production environments.
Additionally I feel quite comfortable in the local sage@GUUG group, which has since effectively merged with the IT-Stammtisch Darmstadt.