vMotion task fails intermittently on VMs after ESXi upgrade to 8.0U2

Products

• VMware vCenter Server

Issue/Introduction

• vMotion task for VMs fail intermittently, usually getting stuck at 15%.
• Manual and DRS initiated migration both are impacted.
• The VM continues running on the source host while showing "unknown" status on the destination host.
• Any task initiated on the VM fails with error "another task is in progress".
• All the tasks get listed on the VM instance created on the destination host.
• Below errors are seen in /var/run/log/hostd.log file of the source host:
  

  VMotionInitiateSrc: Start message: The migration has exceeded the maximum switchover time of 100 second(s). ESX has preemptively failed the migration to allow the VM to continue running on the source.  To avoid this failure, either increase the maximum allowable switchover time or wait until the VM is performing a less intensive workload.

• The swap files for the VM are configured to be stored in a Host Level Swap Directory.

Environment

VMware vSphere ESXi 8.0 U2

Cause

• This issue occurs when the swap files for the VM are configured to be stored in a Host Level Swap Directory.
• A deadlock is encountered during the vMotion when a thread is attempting to fault in memory calling User_FaultAllPages(), while another thread is attempting to unmap some part of memory calling User_MemUnmap().

Resolution

• The issue is addressed in ESXi version 8.0U3b (24280767).
• Workaround to temporarily address the issue is to change the Swap file location to use Virtual Machine directory:
  
  • Select the Cluster -> Configure -> General -> Edit the Swap file location -> Select Virtual Machine directory


• NOTE: To get the VM accessible, please follow the steps below:
  • • Terminate the VM process on the source host.
      Refer: Powering off an unresponsive virtual machine on an ESXi host
    • Restart the Management agents on source and destination host.
      Refer: Restarting Management Agents in ESXi
    • Remove the VM from the inventory and reregister.
      Refer: How to register or add a Virtual Machine (VM) to the vSphere Inventory in vCenter Server