The Execute Storage vMotion for Storage DRS task fails with the error: The available Memory resources in the parent resource pool are insufficient for the operation

Products

• VMware vCenter Server
• VMware vSphere ESXi

Issue/Introduction

Symptoms:

• When you attempt to execute the Storage vMotion for Storage DRS task, you see the error:
  
  The available Memory resources in the parent resource pool are insufficient for the operation.
  
  
• When you attempt a manual Storage vMotion, you see the error:
  
  The host does not have sufficient memory resources to satisfy the reservation.
  

Environment

VMware vCenter Server 5.1.x
VMware vCenter Server 5.0.x
VMware vSphere ESXi 5.0
VMware vSphere ESXi 5.5
VMware vCenter Server 5.5.x
VMware vSphere ESXi 5.1

Cause

This is expected behavior and occurs when ESXi hosts are over-committed in terms of memory reservation. Storage vMotion requires memory reservation equivalent to the overhead memory for each virtual machine that is being migrated. This allocation fails as ESXi hosts are already unable to satisfy virtual machine reservation.

Resolution

To work around this behavior, reduce the memory reservation on the virtual machine you are attempting to migrate.

To reduce the memory reservation on a virtual machine:

1. In vSphere Client, right-click a virtual machine from the inventory and click Edit Settings.
2. In the virtual machine properties windows, click the Resources tab and click Memory.
3. In the Resource Allocation panel, disable the Reserve all guest memory option (if enabled).
4. Reduce the reservation amount within the Resource Allocation panel.
5. Click OK.

Additional Information

Storage DRS による Storage vMotion の実行が次のエラーで失敗する：The available Memory resources in the parent resource pool are insufficient for the operation