Getting an invalid hostname error when attempting to set the vCenter Server hostname

Products

• VMware vCenter Server

Issue/Introduction

When attempting to set the vCenter Server hostname via the vSphere Appliance Management Interface (VAMI), an error is seen that the hostname could not be validated.

Cause

The vCenter Server validates changes to its hostname by attempting to perform a DNS lookup against existing hostnames.

Resolution

The hostname entered into the VAMI settings must be a hostname already defined in DNS, as the appliance does check this.  There is no mDNS-style auto-registration of the hostname provided: it must already exist.