The vSphere Host Profiles are profiles that encapsulate the host configuration and help to manage the host configuration, especially in environments where an administrator manages multiple hosts or clusters in vCenter Server.
Host Profiles provide an automated and centrally managed mechanism for host configuration and configuration compliance. Host Profiles can improve efficiency by reducing reliance upon repetitive, manual tasks. Host Profiles capture the configuration of a pre-configured and validated reference host, store the configuration as a managed object and use the catalog of parameters contained within to configure networking, storage, security, and other host-level parameters. Host Profiles can be applied to individual hosts, a cluster, or all the hosts and clusters associated to a host profile. Applying a Host Profile to a cluster affects all hosts in the cluster and results in a consistent configuration across the applied hosts.
Host Profiles can be used to validate the configuration of a host by checking compliance of a host or cluster against the Host Profile that is associated with that host or cluster.
Reference Host Independence
A dedicated reference host is not required to be available to perform host profile tasks.
When you create a host profile, you extract the configuration information from a specified ESXi reference host. In previous releases, vSphere required that the reference host was available for certain Host Profiles tasks, such as editing, importing, and exporting. From vSphere 6.0 and later, a dedicated reference host is no longer required to be available to perform these tasks. For host profile tasks that require a reference host, an ESXi host that is compatible to the host profile is assigned as a reference host.
Sometimes, a compatible host is not available to validate the host profile during these tasks. If you make small changes to the host profile, validation is skipped and a you see a warning indicating that no valid reference host is associated with the profile. You can then proceed and finish the task.
Due to the introduction of this feature, users can no longer edit or change the reference host from the vSphere Client. The reference host selection occurs at runtime, without notifying users, in the vCenter Server for on-going tasks.
Reference Host Selection
To select a suitable reference host, vCenter Server performs complex version and compatibility checks on the target host.
Starting with vSphere 7.0 Update 3, a major-version vCenter Server instance can manage hosts of all ESXi Update release versions within the respective major version. For example, a vCenter Server 7.0 Update 3 instance can manage ESXi hosts and hosts profiles of version 7.0 GA, 7.0 Update 1, 7.0 Update 2, and 7.0 Update 3. This change affects the reference host selection for particular host profile operations.
Version Check
To select a reference host, vCenter Server checks whether the target host is of the same ESXi Update release version as the host profile. For some operations, the target host can run a later ESXi version than the ESXi version of the host profile. For example, if you want to edit a 7.0 Update 3 host profile, the reference host that validates the host profile cannot be running ESXi 7.0 GA, 7.0 Update 1, or 7.0 Update 2.
Compatibility Check
In addition to checking the version on the target host, vCenter Server performs an extensive compatibility check that includes a subprofile compatibility check in the existing releases. Starting with vSphere 7.0 Update 3, to appoint a reference host, vCenter Server checks the advanced options and the default roles in the target host. A reference host must support the advanced options of the host profile it validates. Also, the default roles in the reference host must match the default roles in the host profile.
Host Profile Operations and Required Reference Host Versions
| Host Profile Operation | Compatible Reference Host Version |
|---|---|
| Edit | The same Update release version as the host profile. |
| Check Compliance | The same or later Update release version as the host profile. |
| Remediation | The same or later Update release version as the host profile. |
| Attach | The same or later version as the host profile. |
| Import/Export | The exact same version as the host profile. |
Host Profiles and vSphere Auto Deploy
You can use Host Profiles and vSphere Auto Deploy to provision physical ESXi hosts with a complete and expected configuration state for virtual switches, driver settings, boot parameters, and so on.
Because hosts that are provisioned with Auto Deploy are considered to be stateless, configuration state information is not stored on the host. Instead, you create and configure a reference host. Then, you create a host profile from the reference host. Next, you associate the host profile with an Auto Deploy rule. As a result new hosts that you provision with Auto Deploy have the host profile applied automatically.
Remediation for these hosts is the same as statefully deployed hosts. When you apply the host profile, you are prompted to customize the hosts and enter answers for the policies that you specified during the host profile creation.
syslog to store logs in a remote server. For more information on setting up a syslog from the Host Profiles interface, see the
vSphere Installation and Setup documentation.
For more information on setting up an Auto Deploy reference host, see the VMware ESXi Installation and Setup documentation.
