An administrator needs to upgrade the guest operating system installed in a virtual machine. What should the administrator do to ensure support by ESXi?

To ensure support by ESXi after upgrading the guest operating system installed in a virtual machine, performing a guest OS and product search in the VMware Compatibility Guide is essential. This guide provides the most accurate and comprehensive information about supported guest operating systems for various versions of VMware products, including ESXi.

By checking the Compatibility Guide, the administrator can confirm that the specific version of the guest operating system is compatible with the version of ESXi they are using. This is crucial because running an unsupported guest OS can lead to performance issues, instability, or lack of support if problems arise after the upgrade. The guide offers details on supported OS versions, which are critical for ensuring that features and integrations work correctly.

While taking a snapshot before an upgrade is a common best practice for backup purposes, it does not guarantee the compatibility of the guest OS with ESXi. Similarly, checking the vendor's web page or the guest OS version drop-down menu in the VM settings may provide some information, but these resources do not offer a comprehensive view of support from VMware's perspective. Only the Compatibility Guide consolidates all necessary compatibility information in one place, making it the most reliable action to take prior to an OS upgrade.