You can deactivate support for non-ASCII characters for virtual machine file and directory names by modifying the /etc/vmware/hostd/config.xml file.
By default, ESXi supports the use of non-ASCII characters for virtual machine file and directory names. You can deactivate this support by modifying the /etc/vmware/hostd/config.xml file. After you deactivate this support, you can still enter non-ASCII characters for virtual machine names. vSphere user interfaces display the virtual machine names in the non-ASCII characters, but ESXi converts the actual file and directory names to ASCII strings.