IT Monitoring with Nagios

Nagios Howto's

Nagios is a great success story of OpenSource software. A monitoring system build with a core set of features, a fast and responsive web interface and a simple API to create custom plugins in whatever language prefered is blowing away the commercial competition.

A few years ago I started publishing Nagios how-to articles on my homepage, and when traffic increased and the content grew too much, I finally decided it's time to move it into it's own dedicated website. Please follow the link to and update your bookmarks.

Embedded System Design

Embedded System Howto's

I have been working with embedded systems from Rabbit Semiconductor. Despite the *funny* name, Rabbit systems are easy to develop for due to their C-compiler implementation and outstanding systems documentation. Available at a low price and with networking features up-to-date, Rabbit boards are a joy to work with, inspiring me to write a library for accessing parallel-port LCD displays.

Remote VPN Networks

VPN Network Howto's
VPN Network Howto's

When I managed our suppliers remote network support connections, development of complex VPN, firewall and NAT setups were required. Centralized VPN concentrators plus small site-to-site VPN devices of mixed origins had to be supported and configuration knowledge to be exchanged. The most common VPN devices were Cisco's smallest PIX 501 and Cisco 831 together with Linux.

Database Howto's

Database Howto's

Modern business software applications use a Relational Database Management System (RDBMS) as their backend data store. Relational databases are optimized for fast transactional operations and they allow to build comprehensive data views by querying organised data (data-warehouse). Below are some tips about how to access them.

Apache and related Web Howto's

Apache Web Howto's

There is no way around the world's number one webserver. Although not the fastest, it is a stable and versatile platform. First released in 1995, it quickly became a longtime success story of open source software. Below are some How-to's I needed to remember and found it worth to write them down.

OpenSSL Howto's

OpenSSL Howto's

The de-facto standard implementation of SSL is OpenSSL. Matured over the past years, It is the base for security layer implementations in communications software. Handling is non-trivial, and in the earlier days documentation was sparse.

Online Certificate Tools

These tools are part of the WebCert application, more information about WebCert is here.

Misc Items

The OpenSSL Manuals

OpenSSL API Examples

Solaris Howto's

Solaris Howto's

SUN's Solaris operating system had been around since the early 90-ties when it proved to be a very solid OS for running the upcoming Internet services 24x7. It's popularity waned with the success of Linux and the shift from using reliable brand systems to clustered, cheap Intel hardware that could soon match SUN's Sparc CPU performance.

Base64 Howto's

Base64 Howto's

Base64 converts data reliably into a ASCII string. First used for encoding binary attachments to e-mails, the MIME content transfer encoding allowed binary data to be transferred over media that could only handle text. There, Base64 ensures the data stays intact without modification during transport. Apart from e-mail, Base64 is now commonly used in a variety of applications.

Various Howto's

Various Howto's

Below are how-to's that did not generate a separate category. Many are Linux-related, but there are also the networks subnet cheat sheets, how many files can be in a directory, or how to work with pointers in Perl.

Security and Audit-related Howto's:

Programming-related Howto's:

Linux Cluster for High Performance Computing

How to build a diskless Linux Cluster
I have been fascinated by clusters since 1995, when DEC VMS clusters where state-of-the-art and first Windows clusters emerged for simple storage sharing. Almost a decade later, cluster technology becomes mainstream through Linux, with falling hardware prices making it affordable for "home" use. What could I use a cluster for? Finally start my education in 3D Graphics Rendering and Computer Art Design? Donate power to SETI? Compute rainbow tables and check out new ways of crunching passwords? [read article]