An administrator runs a two-node vSphere cluster, which contains two domain controller virtual machines (VMs). The administrator wants to ensure that…

The primary goal is to keep the two domain controller VMs on separate hosts to ensure high availability, but critically, this must not prevent maintenance operations. In a two-node cluster, a strict ("must") anti-affinity rule would block a host from entering maintenance mode, as DRS would be unable to move its VM to the only other available host without violating the rule.

A "should" rule provides the necessary flexibility. By creating two "Should run Virtual Machines to Hosts" anti-affinity rules (e.g., DC1 should not run on Host B, and DC2 should not run on Host A), the administrator instructs DRS to keep the VMs separate during normal operation. However, DRS is permitted to violate this preferential rule when necessary, such as evacuating a host for maintenance.

A. A 'Must run' rule is too restrictive. It would prevent a host from entering maintenance mode, as DRS cannot violate a "must" rule.

B. A 'Virtual Machines to Virtual Machines' anti-affinity rule is a "must" rule by definition and would block maintenance operations in a two-node cluster scenario.

C. A dependency rule is a vSphere HA setting that dictates the startup order of virtual machines after a host failure, not their placement for resource balancing.

1. VMware vSphere 8.0 Documentation

"vSphere Resource Management"

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Page 80

"Behavior of DRS with Affinity Rules":

"DRS does not evacuate a virtual machine from a host entering maintenance mode if doing so violates a 'must' affinity rule." This directly supports why options A and B are incorrect.

"DRS might violate a 'should' rule in order to evacuate a virtual machine from a host entering maintenance mode." This supports the choice of a "should" rule (Option D) as the correct solution.

2. VMware vSphere 8.0 Documentation

"vSphere Resource Management"

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Page 80

"VM-VM Affinity and Anti-Affinity Rules":

"VM-VM affinity and anti-affinity rules are 'must' rules." This confirms that the rule type in option B is a "must" rule and therefore unsuitable for this scenario.

3. VMware vSphere 8.0 Documentation

"vSphere Resource Management"

PDF

Page 79

"VM-Host Affinity Rules":

"You can create two types of VM-Host affinity rules

'must' rules (required) and 'should' rules (preferential)." This confirms the existence and purpose of the rule type described in option D.