vMotion fails with the error: The migration was cancelled because the amount of changing memory for the VM was greater than the available network bandwidth, meaning the migration was not making forward progress
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vMotion fails with the error: The migration was cancelled because the amount of changing memory for the VM was greater than the available network bandwidth, meaning the migration was not making forward progress

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Article ID: 332734

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Updated On:

Products

VMware vSphere ESXi

Issue/Introduction

Symptoms:

  • Cannot vMotion a virtual machine
  • Performing a vMotion of a virtual machine fails
  • You see the error:

    "The migration was cancelled because the amount of changing memory for the VM was greater than the available network bandwidth, meaning the migration was not making forward progress. Please attempt the migration again when the VM is not as busy or more network bandwidth is available."

Environment

  • VMware vSphere vCenter
  • vSphere ESXi

Cause

This issue occurs when the amount of changing memory for the virtual machine is greater than the available network bandwidth.

Note: Changing memory refers to the amount of memory that has changed since the initial copy. In busy workloads, memory contents may change faster than they can be transferred over the network.

Resolution

To resolve this issue:

  1.  Verify network connectivity between the source and destination hosts:
    1. Check network status on both hosts
    2. Verify there are no network errors in the logs
  2. Check the VMkernel port configuration for vMotion on both hosts:
    1. Log in to the vSphere Client
    2. Select the host in the inventory
    3. Go to the Configure tab
    4. Under Networking, select VMkernel adapters
    5. Verify the VMkernel adapter used for vMotion is properly configured and enabled

  3. Examine the network switches and physical connections:
    1. Ensure all physical network connections are secure
    2. Check for errors or port issues on physical switches
  4. Review firewall settings:
    1. Verify required ports for vMotion are open between hosts
    2. Consult vSphere Security documentation for required ports

  5. Analyze network performance:
    1. Use network monitoring tools to check for congestion or packet loss
    2. Consider temporarily increasing network bandwidth allocated to vMotion

  6. Check for driver and firmware compatibility:
    1. Review the VMware Compatibility Guide for network adapters
    2. Update network adapter drivers and firmware if necessary

  7. Retry the vMotion operation when:
    1. The virtual machine is less busy (lower memory change rate)
    2. More network bandwidth is available

  8. Consider network design factors:
    1. When vMotion network shares a physical NIC with another busy portgroup, vMotion may be unable to utilize the full bandwidth
    2. Review the values of Traffic Shaping on the vMotion port group for accuracy
    3. For VMs with large memory configurations, consider using higher bandwidth NICs (10Gb or higher)

  9. If the issue persists after trying the above steps:
    1. Generate a support bundle from both source and destination hosts
    2. Include vCenter Server logs if DRS is involved
    3. Contact VMware support for further assistance