System Sizing Guidelines for Integrity Virtual Machines Deployment -- Hardware Consolidation with Integrity Virtual Machines

9
Consolidation Considerations and Utilization Goals
After you collect utilization information for all of the workloads, consider the capacity of the target
physical server in the context of these workloads. Specifically, you need to identify the maximum
aggregate hardware utilization level that is acceptable. This level ultimately determines how many
workloads you should consolidate on the target server.
Utilization Thresholds
HP Consulting has found that average utilization in a large sample of data centers is near 50%.
Other studies indicate an average utilization nearer 30%. Many data centers have a large number
of servers with utilization well below 20%; for these sites, hardware consolidation achieving 50%
utilization provides substantial savings. Figure 1 illustrates the typical utilization curve for servers in
major data centers.
Figure 1 – Representative curve of server utilization across a data center
Consolidating for utilization levels of 80% to 100% is probably not realistic for several reasons.
Extremely high utilization targets, or thresholds, allow no room for error and do not accommodate
spikes in utilization. In late 2005, Gartner
1
recommended that their clients “target 40% to 50%
final average utilization” as a best practice in deploying and managing server virtualization.
1
Server Virtualization: Taking Charge of Your Servers, Tom Bittman, Gartner 24
th
Annual Data Center Conference, December 2005
0
20
40
60
80
100
Average Server Utilization