Server Consolidation: Definitions & Approach Enterprise Systems Group (ESG)

Dell White Paper

By Todd Muirhead

April 2002 Contents

Executive Summary...... 3 Planning...... 4 Logical Consolidation...... 5 Physical Consolidation...... 6 Workload Consolidation...... 8 Conclusions...... 10

April 2002 Page 2 Dell Enterprise Systems Group Section 1

Executive Summary

Server Consolidation is often defined to mean running many differing types of applications, such as email, financials, database, and file serving, on a single very large server. However, many of the same benefits of consolidating to a single, or very few, servers can be achieved through other consolidation approaches. Due to this, the definition of server consolidation is broad and has evolved to encompass much more than running everything possible on as few servers as possible.

The most important part of a server consolidation initiative is the planning and analysis of end user requirements, application requirements, and server environment. Only by having a good understanding of the requirements and challenges of any given infrastructure can a beneficial server consolidation program be proposed, planned, and implemented.

In order to fully understand server consolidation in today’s Information Technology (IT) environment it is necessary to break it down into three different approaches: logical, physical, and workload. Studying existing servers and how they are used determines what type of server consolidation to pursue, and to what degree. Most implementations of server consolidation will actually be a mixture of the three approaches to achieve the maximum benefit.

Logical consolidation is adopting the same management and control processes across all servers. This approach to consolidation is relatively easy to achieve and will provide benefits quickly. Physical consolidation involves the geographical location of servers and attempts to keep these locations to a minimum. Workload consolidation is the actual reduction of the number of servers by moving from multiple smaller servers to fewer larger servers.

April 2002 Page 3 Dell Enterprise Systems Group Section 2

Planning

An analysis of the environment is crucial in determining what type and how much consolidation is needed or is possible. While great benefits can be gained by going to a single physical data center for all servers, the associated cost of connectivity of all regional offices may make such a configuration financially impractical. It might make sense to have regional data centers, or to simply focus on better systems management for all existing offices allowing for fewer administrators to remotely manage many systems.

It is also important to understand the capacity requirements of each server. If all fileservers are currently only utilized at about 10%, then it would make sense to condense to fewer systems. If a database server is already running at 85% utilization, then it probably needs to remain a dedicated database server. It cannot be overemphasized how important it is to do a good analysis before starting a server consolidation.

Dell has a Server Consolidation Return on Investment tool that helps to begin the analysis process. The tool is designed so that Dell customers can work with their account representatives to enter information that pertains to their environment. The more accurate and complete the information that is entered into the tool, the better the analysis report that is produced.

April 2002 Page 4 Dell Enterprise Systems Group Section 3

Logical Consolidation

The easiest type of consolidation to achieve is logical consolidation. Implementing systems management across all servers and using common administration and setup processes can help save a great deal of time. And it can help save resources too, as fewer system administrators are needed to manage the same number of servers.

An enterprise wide implementation of systems management provides great benefits. Dell OpenManage™ products provide functionality that allows for thousands of Dell™ PowerEdge™ servers to monitored and maintained from a central console. When a Dell Remote Access Card (DRAC) is added to a PowerEdge server, it adds the capability of a remote console redirect. This allows administrators to remotely: see the server’s video screen; take control of its mouse and keyboard; and perform maintenance tasks.

In addition to being able to better manage all servers, a systems management package also offers the advantage of providing a clear inventory of all systems. This allows the organization/enterprise to have a real-time picture of how many systems of what type are currently deployed.

In November 2001, Dell Solution Enablement Lab implemented a logical consolidation in order to get better utilization of existing equipment. The Lab installed Dell OpenManage IT Assistant and Server Administrator management applications, which were used to get a full inventory of all systems. Engineers were then able to reserve time on servers for upcoming projects and management was able to plan more effectively for new server purchases.

Logically all of the servers are consolidated around a set of management tools and processes. These can be scaled to include how applications are set up and deployed, depending on the environment. By streamlining the number of processes used in the setup of servers and applications, their management becomes much easier to document and maintain.

April 2002 Page 5 Dell Enterprise Systems Group Section 4

Physical Consolidation

The Physical Consolidation approach is to have all servers located in a single location or as few locations as possible. A reduction in the number of data centers can lead to a reduction in costs. Administration typically becomes easier, because administrators are centralized, leading to a more efficient use of their time during maintenance of existing servers and during setup of new servers. By using server racks to house many servers in a small amount of space, much less real estate is required. And upgrades to server applications can become much faster due to the centralized location of servers.

Physical consolidation also allows for the use of server clustering technology. Clustering servers together helps improve application availability to users, because if one server in a cluster has a failure, the system is designed so that the application will continue to be available from the other server or servers in the cluster.

Storage Area Networks (SANs) provide a highly available, high performance storage backend to multiple servers. Although it is possible to create Storage Area Networks where the storage and servers are geographically separate, the cost can be significantly reduced if the servers and storage are in the same building or campus. SANs are designed to offer the advantages of lower cost per MB, higher scalability, and better fault tolerance than storage that is directly attached to servers. Using a SAN is an example of storage consolidation. In order to further extend the benefits of server consolidation it makes sense to consolidate storage as well. An upcoming Dell whitepaper on storage consolidation will discuss in detail the different types of storage consolidation and its benefits.

Dell offers some extremely rack dense servers including the PowerEdgeTM 1650. Each PowerEdge 1650 is a two-processor server with redundant power supplies, embedded RAID, and optional lights out management capabilities. Up to 42 PowerEdge 1650s can be loaded into a single full height server rack. This configuration is ideal for a large web server farm supporting thousands of users.

In addition, new blade server technology allows for many more servers to be installed into a smaller space. The Dell PowerEdge 1655MC allows for up to six two-processor servers to be installed in only 3U of rack space. This is an increase in rack density over 1U servers and is an opportunity to increase the value of a physical consolidation.

April 2002 Page 6 Dell Enterprise Systems Group A large computer education organization used a physical consolidation approach when it recently implemented a single data center to provide the test systems for all of its classes held worldwide. Students connect to the servers over the Internet and run their lab exercises on real servers. Instructors no longer have to spend a day of prep time to get the lab environment setup, as it is up and maintained at a centralized data center. In addition, software upgrades have become much easier, as all systems are upgraded as soon as the software is available and has been tested at the data center. This allows students to get education on the latest software releases much faster than if individual field servers had to be upgraded.

By centrally locating servers in as few locations as possible, real advantages and related cost savings can be gained. Physical consolidation is not without its risks and must be done after a careful analysis of the requirements of the entire organization. Moving all servers to a single data center may not be appropriate for all IT organizations, but centralization of all email servers or web servers to a single data center can result in big savings. Physical consolidation allows organizations to focus their highly skilled person on higher-value tasks, which gives the IT staff the opportunity to add more value to the business.

April 2002 Page 7 Dell Enterprise Systems Group Section 5

Workload Consolidation

Consolidating workload means using fewer larger servers to replace what was being accomplished by a large number of smaller servers. When reducing the number of servers there are two distinct paths that can be followed. The easier and more common approach is to continue to dedicate a server to a specific application, but to use fewer servers by taking advantage of multiprocessor systems using the most recent technology. The other, and more complex, path is to take disparate applications and put them on the same server. An example would be using a single server to provide file-print and email services. This type of consolidation can be very powerful in helping to reduce costs, but it is also is the most difficult to plan and implement.

A workload consolidation requires the most planning and analysis of the existing server infrastructure, because it is a change in the workload that the servers will be running. In the logical and physical approaches to consolidation there is no change in the number of servers or the number of users they are supporting. The actual workload that each server is running does not change in these approaches, so there is a low risk of failure due to improper server sizing. In workload consolidation a greater number of users will be accessing each server. In addition, if different applications are consolidated onto a single server then the differences in those application requirements must be considered when sizing the server. In order to avoid unnecessary complexity Dell recommends beginning by grouping servers of like functionality and avoid mixing different types of applications together on the same server.

Although workload consolidation is the most difficult to plan and implement, it can also provide the greatest benefits. “Pursuing the ultimate consolidation goal of a single system image for all distributed server applications can yield great rewards when balanced with the expense, but the potential for a poor or failed implementation is far greater.”1 Administration and management are easier because there are fewer servers. This means fewer systems upon which to install software updates and patches. Fewer servers also result in lower software licensing costs for both operating systems and applications. Workload consolidation can also result in a much more efficient use of resources. Replacing under-utilized one or two processor servers with a single four- or eight-processor server that will be utilized at a higher level is more efficient.

1 Gartner presentation “Server Consolidation: Desired by Many, Achieved by Few”, J. Phelps, December 2001.

April 2002 Page 8 Dell Enterprise Systems Group It is easy to see the benefits of workload consolidation in a simple example of file and print servers. Instead of having ten file and print servers, with each one dedicated to a department and only 10 to 15 percent utilized, they are replaced with one or two large file and print servers that are shared by the same ten departments. Software licensing costs are greatly reduced. In addition, backup of all user data can now be accomplished much more easily by attaching a tape library directly to the file server.

Microsoft® Exchange 2000 is another application that can be effectively consolidated to fewer servers. By taking advantage of the new multiple data store features in Microsoft Exchange 2000 Server it is possible to support more users on a single server and still be able to backup and restore each data store within required service level agreements (SLAs).

April 2002 Page 9 Dell Enterprise Systems Group Section 6

Conclusions

By approaching server consolidation with the right method for the right environment, great benefits are achievable. It is important to analyze the entire server environment before beginning any server consolidation program. In a real world server consolidation implementation it is likely that all three approaches can be used to some degree. In particular, logical consolidation is always a good first step to ensure that a clear picture of the server resources is available before continuing with physical and workload consolidation steps.

Dell offers services to assist in a consolidation effort. A consolidation readiness assessment is performed to gather all the information needed for the planning and analysis phase. Following the assessment, additional services are available to plan and validate a server consolidation approach. Onsite capacity planning and optimization can be included in this process. Using these services assists in getting a server consolidation program planned and implemented quickly by leveraging the experience the Dell services team has had with other consolidation projects.

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April 2002 Page 10 Dell Enterprise Systems Group