What are the two types of rules that can be created in a vSphere DRS cluster to specify affinity?

In a vSphere Distributed Resource Scheduler (DRS) cluster, affinity rules and anti-affinity rules are used to control the placement of virtual machines (VMs) relative to each other based on specific needs or preferences.

Affinity rules allow you to define that certain VMs should run on the same host, which can be beneficial for performance reasons or application requirements, such as when VMs are part of the same application stack and benefit from low latency communication. This grouping can enhance performance as it minimizes network latency between the VMs.

On the other hand, anti-affinity rules specify that certain VMs should not run on the same host. This is particularly useful for high availability, as you want to ensure that critical components of an application are distributed across multiple hosts. In the event of a host failure, the remaining hosts would still have VMs running without impacting the entire application or service.

The combination of these two types of rules provides the flexibility needed to optimize resource usage and maintain service availability according to the specific requirements of the workloads running in the DRS cluster.