Networking issue reported for manual virtual machine vMotion where DRS migrated the virtual machine back to the src esxi host

Products

• VMware vCenter Server

Issue/Introduction

• Affinity Rule is configured to Keep Virtual Machines Together for some Virtual Machines
• A virtual Machine in the Affinity rule is manually vMotion migrated to another host
• DRS migrates the single manually migrated virtual machine back to the original src host
• RARP are observed on manual vMotion migration.

Environment

vSphere 7

vSphere 8

Cause

• Affinity rule Keep Virtual Machines Together and Separate Virtual Machines can be violated by a migrating using vSphere vMotion. The operation will succeed even though it would violate the rule.
• vSphere resource management features such as DRS never take any action that can violate a mandatory VM-Host affinity rule.
• RARP request is sent after performing a vMotion when vSwitch properties is set to Notify Switches.

Resolution

• Enable DRS to comply with rules if a virtual machine is manually migrated and violates the rule. DRS will automatically remediate.
  
  or 
  
  
• Without vSphere DRS, users must correct virtual machine placement to comply with rules. In scenarios, when vSphere DRS is not enabled, there will be no automatic remediation of virtual machine placement. This includes violations because of manual migrations, and violations that might occur if new rules are defined that would violate current virtual machine placement. 
  
  or
  
  
• Create the virtual machine and host groups to which the VM-Host affinity rule applies. Any hard (must and must not) Virtual Machine to Hosts rule type cannot be violated by a user-initiated migration. For example, if a rule is defined that VM-1 and VM-2 (VM Group) must run on hosts ESX-01 and ESX-02 (Host Group), an attempt to migrate the virtual machines to hosts outside of the Host Group will be blocked. 

Additional Information

• Using Virtual Machine Affinity Rules without vSphere DRS