If you're looking for Linux-based, hardware-agnostic storage software, check out Gluster, an open source project for creating a distributed filesystem. It provides fast performance, high availability, and horizontal scalability by spreading storage volumes over redundant cluster nodes. Here's how you can build a Gluster distributed storage system yourself.

Solr is an open source search server based on Apache Lucene. Lucene provides Java-based indexing and a search library, and Solr extends it to provide a variety of APIs and search functionality, including faceted search and hit highlighting, and handles Word and PDF document searching. It also provides caching and replication, making it scalable, robust, and very fast.

On Linux systems, initialization (init) scripts manage the state of system services during system startup and shutdown. When the system goes through its runlevels, the System V init system starts and stops services as configured. While this tried-and-true technology has been around since the dawn of Unix, you can now create modern and efficient CentOS 6 init scripts by using Upstart, an event-based replacement for System V init.

Apache is still by far the most widely deployed HTTP server, according to the latest Netcraft web server survey, but nginx has been slowly, steadily gaining market share, thanks to its blazing speed. If you want to try a faster web server and move from Apache to nginx, you'll probably have to change some of your websites' configurations, starting with rewrite directives. To migrate rewrite rules from Apache to nginx, start with these tips and tricks.

Tomcat, the most popular open source implementation of the Java Servlet and JavaServer Pages specifications, is frequently integrated with Apache, the most popular open source web server. Here's a tutorial that shows you three ways to use Tomcat and Apache together.

Computer cloning, also referred to as ghosting or imaging, involves setting up the operating system, drivers, software, and data on one computer, then automatically replicating the same setup on other computers. Clonezilla Server Edition and FOG are the most popular open source cloning systems. While both do similar jobs – clone and restore machines over the network using tools and services such as partimage, tftp, and PXE – they go about it very differently. Which is right for you depends on your network's configuration and composition.

For years, MySQL has been the king of open source database servers. It powers a large part of the web and numerous applications worldwide. However, concerns about the future of MySQL since its acquisition by Oracle, combined with an increasing demand for performance and scalability, have driven people to consider alternative options, such as PostgreSQL and MongoDB. Switching to either of those alternatives, however, is not a simple proposition. MariaDB, by contrast, offers enhanced performance in a DBMS that can be a drop-in replacement for MySQL.

Varnish is a standalone HTTP accelerator that provides efficient and powerful web caching mechanisms. In addition to performing web caching, Varnish can also act as a web application firewall (WAF) and a load balancer, and it can be integrated with any back-end web server.

Setting up Linux on multiple machines can take a lot of time and effort, but it doesn't have to. With Kickstart, you can customize automatic installation of any Fedora-based distribution, including CentOS, on new servers. Kickstart can install not only the operating system but also all the applications you expect to run. And to make everything run as quickly as possible, you can store Kickstart files and Linux packages on a local Apache web server, which then servers as your network installation and update server, saving you bandwidth every time you roll out a new machine.

The Fedora Project's 389 Directory Server, an advanced and complete open source LDAP (Lightweight Directory Access Protocol) server, can satisfy every corporate demand for an alternative to popular commercial solutions such as Microsoft's Active Directory. It come bundled with a powerful, intuitive, easy-to-use graphical interface to facilitate the administration of directory servers.