Diagnostics provides fleet-wide monitoring of successful and failed vSphere vMotion and information that will enable you to diagnose vMotion performance issues and failures.

The vMotion page lists the success and failure trend over seven days, the clusters with the highest number of vMotion over seven days, and every vMotion within the fleet over seven days. The timing parameters for a successful vMotion provide you an understanding of how long the vMotion takes. You can troubleshoot your failures by examining the vSphere vMotion-specific statistics displayed on the dashboard. In addition, the details page provides summary statistics that help you detect unexpected trends.
  1. On the vMotion dashboard, click the virtual machine name displayed in the table.
  2. Click the icon to open the vSphere vMotion operation and check these three parameters:
    • Pre-copy Time: The duration it takes to copy the virtual machine's memory from the source ESXi host to the destination ESXi host. Memory Precopy time is a function of the VM's memory dirty rate on the source ESXi host, the vMotion network transmit rate, and the memory allocation rate on the destination ESX host. vMotion memory precopy is programmed to saturate the vMotion network. In cases where memory pre-copy can't saturate the vMotion network, it likely points to an infrastructure health issue on either the source ESXi, vMotion network, or destination ESXi. Examples of infrastructure health issues are CPU and memory overcommitment of a source or destination ESXi host and vMotion tasks failing due to network congestion or a malfunctioning NIC on the source or destination host, memory errors, or slow storage.
    • Pre-copy Bandwidth: Data transfer rate during the vMotion pre-copy phase.
    • Switchover Time: Duration of final memory copy and switchover from source and destination hosts.
  3. You can refer to this Knowledge Base (KB) article to troubleshoot some common vSphere vMotion-related issues.
To investigate vMotion failures, you can use the trend chart at the top of the page and the filters to gain an understanding of which users are triggering the failures and in which hosts, clusters, and vCenter instances. You can view the details for the time intervals displayed in the trend chart by using the time filter. Then, follow the troubleshooting flow provided in What is Diagnostics for VMware Cloud Foundation.

vSphere vMotion Limitations

  • Cross vCenter migrations are not supported.
  • Hybrid Cloud Extension (HCX) migrations are not supported.