With the announcement of vSphere 6 becoming Generally Available, I figure it a good time to shine some light on some of the updated features of Host Profiles. Host Profiles allow you to establish standard configurations for your ESXi hosts and to automate compliance to these configurations, simplifying operational management of large-scale environments and reducing errors caused by misconfigurations. In this release we’ve made several improvements which will make updates and applying of Host Profiles easier and with minimal disruption.
Maintenance Mode Removal
In previous versions of vSphere, Host Profiles required administrators place the specified ESX hosts into maintenance mode to apply the Host Profile. This can be very inconvenient for our customers, especially when those hosts have a high VM:Host ratio. In vSphere 6, we have updated Host Profiles to only require maintenance mode if the properties being set by the specified Host Profile require it. For any settings that normally would not require a host to be in maintenance mode to update, Host Profiles will apply them without going into maintenance mode. This is a huge benefit to customers who want to allow the virtual machines on a given host to continue running (without the need for vMotion), while still applying a Host Profile.
Reference Host Independence
Host Profiles relies on a ‘Reference Host’, a host that is properly configured’, from which profiles can be created and used against other like hosts. In vSphere 5.5 and earlier, the reference host had to be online and available to be able to apply Host Profiles to the other hosts. In vSphere 6 there is a decreased dependence on the reference host. This means that a Host Profile can be applied to another ESX host even if the Reference Host is unavailable. vSphere does not stop you from applying the profile, however, if you apply a profile without the reference host available, the profile will not be able to validate properly. This could result in the host profile failing to apply to the host if the profile itself was not created correctly.