For most organizations, server consolidation provides a means to solving data center crises, particularly the spiraling
costs for cooling, space and power. But there's a danger in investing in too much of a good thing, in striving for maximum virtualization without considering, among other things, new server and storage costs.
In this tip, we'll look at capacity planning tools – VMware Capacity Planner and PlateSpin PowerRecon -- and practices that can help you make intelligent consolidation decisions. I also list a few gotchas that can emerge from using these tools.
As a VMware consultant, my conversations with IT directors often take a turn where they believe that they can virtualize 100% of their existing physical infrastructure largely because a virtualized infrastructure is smaller than a traditional physical infrastructure. Also, with the advancements of greater processing power in a smaller footprint -- quad-core CPUs for example -- companies can now look at purchasing high-powered 1U servers, thus reducing their footprint even further.
So many IT directors are focused on the servers and storage they want to buy. This may be driven by an existing relationship with a vendor or a specific and attractive price point. But too often they take a finger-in-the-air approach to deciding how much compute resource and storage is required. This could end up with the project being over- or underspecified. While the benefits of virtualization and more intelligent servers are great, so is the potential for overstocking your data center. If you deploy too many servers, obviously you run the risk of negating some of that positive virtualization benefit.
How can you intelligently scope the required resource, taking in to account growth and flexibility for functionality such as DRS (Dynamic Resource Scheduling) and HA (High Availability)? There are quite a few capacity planning and virtual machine monitoring tools that can provide concrete metrics. Let's look at two of them that are commonly used in VMware environments.
VMware Capacity Planner and PlateSpin PowerRecon provide tools for gathering information on an existing physical infrastructure. From here, utilizing known server metrics, a scope for consolidation can be created ensuring that the decisions on equipment and specification are made correctly.VMware Capacity Planner
VMware Capacit Planner collects resource utilization data in your IT environments. This gathered information is then used to profile your environment, investigate utilization over a period of time and deliver a defined scope for consolidation. Capacity Planner can intelligently guide you on the number of servers, CPU and memory resource required, based on a moderate or aggressive consolidation exercise. All aspects of your environment are considered, such as the required power draw and specific applications running on each platform. Two engagements are available -- consolidation estimates (CE) and capacity assessments (CA). The CE engagement is geared toward a presales workshop where guidance can be delivered to the customer on what benefits they can expect to see from a consolidation exercise. The CA engagement provides a more in-depth view of an IT organization's infrastructure allowing a roadmap for adoption to be defined and implemented. Capacity Planner gotchas
The downside of VMware's Capacity Planner is that you can only utilize it by engaging an authorised VMware partner. For organizations that have to run on a tight budget, the engagement of a partner for the planning exercise may be difficult to justify, especially is they plan to complete the project in house without any external assistance. Some other potential problems include the following:
- The collector has to have a permanent connection to the internet during the scheduled collection window, so it's not any use for air-gapped environments.
- Any break in the connection between the collector and VMware's data warehouse can cause issues with the quality of the results.
- It may not suit some environments where data security guidelines prevent statistical data being sent to a third party.
- The VMware website used to monitor and generate reports can be slow to respond and subject to timeouts.
Like VMware's Capacity Planner offering, PowerRecon is a planning and analysis tool. Agentless, PowerRecon can gather detailed information on your hardware resources, application workloads and infrastructure services allowing you to plan a sufficient virtualization environment for your business today and tomorrow.
A PowerRecon server is installed at the customer site and through remote queries, gathers the information on a scheduled basis. Each PowerRecon instance can monitor up to 2,000 servers making it an exceptionally scalable solution. Beyond the planning for consolidation stage, PowerRecon still has its uses. It can be utilized in an on-going fashion, allowing you to monitor growth in your data center, ensuring that your infrastructure scales in line with your businesses needs.
PowerRecon is available in five different packages, each package containing additional features. The packages have been divided up intelligently enabling you to buy the correct features for your specific capacity planning or monitoring exercise. The Inventory Edition is free of charge and can provide basic monitoring of up to 100 servers; enough to give you a taste of the product or perhaps even to provide you with the required information.PlateSpin PowerRecon gotchas
There are some user-beware warnings with PowerRecon, too. These include the following:
- PowerRecon can be difficult to install and configure if IIS is locked down – say, with custom security rules -- on the PowerRecon server.
- A lot of labor is involved in more complicated deployment projects.
- PowerRecon can be expensive to use, as licenses are expensive to procure.
Planning your data center capacity is critical to success. It is too easy to expand your data center footprint without monitoring the real utilization of your existing services. By monitoring your capacity you can ensure that your data center will stay lean, fit and healthy for years to come. Resist the urge to impulse shop for new servers!
ABOUT THE AUTHOR: Paul Davey is the CTO and co-founder of Xtravirt Limited, a U.K. based company that provides virtualization consulting services. He has worked in the IT industry for over 12 years within various areas of technology. He can be reached at firstname.lastname@example.org.