This section provides performance best practices for VMware vSphere®vMotion®.
vSphere vMotion Recommendations
Consider the recommendations in this section for the best vSphere vMotion performance. For more detail about vSphere vMotion architecture and performance, see the white paper VMware vSphere vMotion Architecture, Performance and Best Practices in VMware vSphere 5. (Though written about a previous version, much of the material still applies.)
VMware Cloud on AWS supports multiple virtual hardware versions. If you plan to move a virtual machine from VMware Cloud on AWS to an on-premises ESXi host (in a hybrid cloud scenario, for example), make sure the machine’s virtual hardware version is supported by the ESXi hosts on which you intend to use them. You can see what’s supported by each version of ESXi in VMware KB article 2007240.
VMware Cloud on AWS supports encrypted vSphere vMotion. This feature encrypts vSphere vMotion traffic when both the source and destination hosts are capable of supporting encrypted vSphere vMotion (that is, when both hosts are in VMware Cloud on AWS or are running ESXi 6.5 or later). If a virtual machine running on a host that supports encrypted vSphere vMotion is migrated to a host that does not support it, vSphere vMotion traffic will not be encrypted.
Encrypted virtual machines are always moved with encrypted vSphere vMotion. For virtual machines that are not encrypted, vSphere vMotion encryption can be changed from Opportunistic (the default) to Disabled or Required (right-click the virtual machine, select Edit Settings, select VM Options, click Encryption, then select an option from the Encrypted vMotion drop-down menu).
For more detail about encrypted vSphere vMotion architecture and performance, see the white paper VMware vSphere Encrypted vMotion Architecture, Performance, and Best Practice. (Though written about a previous version, much of the material still applies.)
While a vSphere vMotion operation is in progress, VMware Cloud on AWS opportunistically reserves CPU resources on both the source and destination hosts in order to ensure the ability to fully utilize the network bandwidth. VMware Cloud on AWS will attempt to use the full available network bandwidth regardless of the number of vSphere vMotion operations being performed. VMware Cloud on AWS will reserve one core worth of CPU for each 10Gb/s of reported network bandwidth. On i3.metal instances, that amounts to 5.75GHz. Therefore leaving some unreserved CPU capacity in a cluster can help ensure that vSphere vMotion tasks get the resources required in order to fully utilize available network bandwidth.
