What is necessary to ensure successful vMotion across different ESXi hosts?

To successfully perform vMotion across different ESXi hosts, one essential requirement is the presence of shared storage environments. vMotion is a feature in VMware that allows the live migration of running virtual machines from one host to another without downtime. For vMotion to function properly, both the source and destination ESXi hosts must have access to the same storage so that the virtual machine's files can be accessed during the migration process.

When both hosts share a common storage system, the virtual machine's disk files remain accessible throughout the migration, enabling a seamless transfer. This is crucial because, during the process, the VM state, including its memory and CPU states, is also transferred, and having shared storage allows for coordinated access to the VM’s data.

While aspects like identical physical hardware, advanced resource allocation, and similar operating system versions can contribute to the overall environment for optimal performance and compatibility, they are not strict prerequisites for basic vMotion functionality. The critical element for successful vMotion is the shared access to storage since it directly influences the ability to move the virtual machine between hosts without interruption.