DRS rules specify which host a virtual machine must or must not reside on, or which virtual machines must be or must not be on the same host.

A VM/VM DRS rule or a VM/Host DRS rule is violated.

VM/VM DRS rules specify that selected virtual machines should be placed on the same host (affinity) or that virtual machines be placed on different hosts (anti-affinity). VM/Host DRS rules specify that selected virtual machines should be placed on specified hosts (affinity) or that selected virtual machines should not be placed on specified hosts (anti-affinity).

When a VM/VM DRS rule or VM/Host DRS rule is violated, it might be because DRS cannot move some or all of the virtual machines in the rule. The reservation of the virtual machine or other virtual machines in the affinity rule, or their parent resource pools, might prevent DRS from locating all virtual machines on the same host.

Check the DRS faults panel for faults associated with affinity rules.

Compute the sum of the reservations of all the virtual machines in the affinity rule. If that value is greater than the available capacity on any host, the rule cannot be satisfied.

Compute the sum of the reservations of their parent resource pools. If that value is greater than the available capacity of any host, the rule cannot be satisfied if the resources are obtained from a single host.