VMware vSphere Distributed Resource Scheduler (DRS) is responsible for placement of Virtual Machines and balancing of resources in a cluster. The key driver for DRS is VM/Application happiness, and it achieves this by effective VM placement and efficient load balancing. We have a new white paper, which tries to explain how DRS works in basic scenarios and how it can be tuned to behave differently for specific scenarios.
The white paper talks about the factors that influence DRS decisions and provides some useful insights into different parameters that can be tuned in specific scenarios to make DRS more effective. It also explains how to monitor DRS to better understand its behavior.
It covers DRS behavior in specific scenarios with some case studies. Some of these studies are around
- VM Consumed vs. Active Memory – How it impacts DRS behavior.
- Impact of VM overrides on cluster balance.
- Prerequisite moves during initial placement.
- Using shares to prioritize cluster resources.
The paper provides knowledge about the factors that affect DRS behavior and helps understand how DRS does what it does. This knowledge, along with monitoring and troubleshooting tips, including real case studies, will help tune DRS clusters for optimum performance.