DRS Performance and Best Practices

VMware® Infrastructure 3 provides a set of distributed infrastructure services that make the entire IT environment more serviceable, available, and efficient. Working with VMware ESX 3, VMware VirtualCenter 2, and VMware VMotion, VMware Distributed Resource Scheduler (DRS) dynamically allocates resources to enforce resource management policies while balancing resource usage across multiple ESX hosts. This paper is intended for readers who understand the architecture and basic concepts of DRS. See the paper “Resource Management with VMware DRS” for these details. (See “Resources” on page 19 for a link.) This paper identifies various scenarios in which you can benefit from DRS and explains how to configure your environment to take best advantage of DRS. The paper covers the following topics: “Overview of DRS Performance” on page 1 “Resource Allocation for Virtual Machines and Resource Pools” on page 3 “Scaling the Number of Hosts and Virtual Machines” on page 9 “DRS Aggressiveness” on page 13 “Interval Between DRS Invocations” on page 14 “Cost‐Benefit Analysis” on page 15 “Heterogeneous Host Environments” on page 15 “Impact of Idle Virtual Machines” on page 16 “DRS Performance Best Practices” on page 16 “Monitoring DRS Cluster Health” on page 17 “Conclusions” on page 19 “Resources” on page 19