The primary business driver for server consolidation is cost reduction.The primary business driver for server consolidation is cost reduction, but other reasons to rein in "server sprawl" include increased manageability, a more robust server platform and better IT service levels.
Consolidation of server hardware is closely related to application and storage consolidations—certain types of server consolidation involves converging applications on a single machine and sharing data in storage pools. Before starting any consolidation project, IT managers should take care to ensure that critical applications will run smoothly and can co-exist in a consolidated environment.
Some transaction processing applications have high network bandwidth requirements and are distributed in server farms at different geographic locations to provide a better user experience. IT managers need to make sure that consolidating these server farms wont negatively impact throughput or add significant network bandwidth costs.
Companies looking to consolidate servers have a wide range of choices for doing so.
High-end x86 (Windows/Linux) and RISC (Unix/Linux) server platforms provide the foundation for rational server consolidation, where multiple homogeneous or heterogeneous applications are deployed on fewer but more powerful server platforms. Common operating systems are used, along with hardware/software partitioning and virtualization.
Rational consolidation also involves running workload management software to dynamically allocate system resources to applications in need. Rational consolidation is the most complex and risky consolidation model, but it has the potential to provide the greatest return on investment.
Server vendors such as IBM, Sun Microsystems Inc., Hewlett-Packard Co., Dell Computer Corp., Unisys Corp., NEC Corp. and Fujitsu Software Technology Corp. offer enterprise server consolidation products and services. For example, Suns newly released Sun Fire 15K (see review) provides dynamic-domain capabilities, a high-level hardware resource partitioning feature that allows IT managers to dynamically allocate hardware resources to applications running within separate domains.
Ultradense blade or brick server technologies are maturing quickly and can also help with physical consolidation strategies.
A method of rational consolidation that is growing in popularity is server virtualization.
Virtualization software vendors such as VMware Inc., SWSoft Inc. and Connectix Corp. provide products that allow companies to perform rational consolidation by encapsulating multiple guest operating systems on a single high-end server host.
Although these products are immature compared with mainframe-class partitioning and workload management systems, they are the most viable option available because native partitioning and workload management capabilities are still lacking in server operating system products.
IT managers undertaking any server consolidation project should also consider management software such as BMC Software Inc.s Patrol, which provides enterprise resource allocation and performance assessment capabilities.
Before IT managers select any consolidation approach or product, they should carefully analyze internal needs and take steps to avoid pitfalls.
Organizational politics can play a big role in hindering consolidation. For example, independent business units might be reluctant to consolidate their applications on a server with other departments applications. For this reason, its important to be able to justify clearly the value of consolidation and implement IT control strategies that will overcome any problems that consolidation might invite.
Its also important to remember that server consolidation is an ongoing process, not a one-time fix. IT managers should carefully project their consolidation strategy over time to gauge the risks and extended ROI.
Server vendors provide professional consulting services and resources to help customers plan consolidation strategies. For example, Dell provides a Server Consolidation ROI Analysis Tool at www.dell.com that enables users to perform simple ROI calculations (based, of course, on consolidation on Dell servers and management software).
Technical Analyst Francis Chu can be reached at francis_chu@ziffdavis.com.
IT Infrastructure 
