vMotion of a virtual machine with Latency Sensitivity set to High fails at 14 %

Products

• VMware vCenter Server
• VMware vSphere ESXi

Issue/Introduction

• Virtual macine Latency Sensitivity is set to High.
• vMotion task fails at 14%
• We will see error similar to:

  Operation timed out. The VM failed to resume on the destination during early power on. Module Memsched power on failed.
  An error occurred while parsing scheduler-specific configuration parameters. Invalid memory setting memory reservation (sched.mem.min 0should be equal to memorysize()

  
  
  
• In the location less /var/run/log/hostd.log we see errors as below: 

  info 'Vcsvc.VMotionSrc (1xxxxx145643545)'] ResolveCb: VMX reports needsUnregister = false for migrateType MIGRATE_TYPE_VMOTION
   info 'Vcsvc.VMotionSrc (1xxxxx3145643545)'] ResolveCb: Failed with fault: (vmodl.fault.SystemError) {
  --> dynamicType = <unset>,
  --> faultCause = (vmodl.MethodFault) null,
  --> reason = "Timed out waiting for migration start request.
  --> ",
  --> msg = "",
  --> }

   

• vMotion succeeds when the Latency Sensitivity setting is changed to Normal.
  
  
  

Environment

VMware vSphere ESXi 6.x
VMware vSphere ESXi 7.x

Cause

If Virtual Machine has a Latency Sensitivity set to high, memory reservation needs to be set on the Virtual machine .

Resolution

To ensure that the virtual machine (VM) has a memory reservation equal to its configured memory size, follow these detailed steps:

Step 1: Determine the Memory Size

1. Open the Virtual Machine Summary Tab:

   • Navigate to the Summary tab of the VM in the client (e.g., vSphere Web Client or vCenter).
   • Note the Memory Size listed in the VM's summary.

2. Review the vMotion Failure Stack (if applicable):

   • If the memory size is unclear from the summary tab, check the error stack of the vMotion failure log for the memory configuration details.

Step 2: Configure the Memory Reservation

1. Edit VM Settings:

   • Right-click the VM and select Edit Settings.

2. Access Memory Resources:

   • Go to the Resources tab.
   • Select Memory.

3. Set Memory Reservation:

   • Input the previously noted memory size in the Reservation field.
   • Optionally, check the box for Reserve all guest memory (All locked) to ensure all the memory is reserved for the VM.

4. Save Changes:

   • Click OK to apply the changes.

Step 3: Validate the Configuration

1. Confirm that the memory reservation is updated in the Summary or Resource Allocation tab.
2. Attempt the vMotion again to ensure the issue is resolved.

This ensures the VM's memory reservation aligns with its configured size, which is crucial for preventing resource contention issues during operations like vMotion.

The vMotion should now succeed.

Additional Information

• An alternative to reloading on the command line would be to attach a host device to the VM.
• We can navigate to the location Edit Settings -- > CDROM -- > Select Host Device (DO NOT select 'Connect' or 'Connect at power on') -- > OK.
• Then reverse the process to detatch the host device.