Chapter 1. Introduction
You can use host-based subscriptions for Red Hat Enterprise Linux virtual machines in the following virtualization platforms:
- Red Hat Virtualization
- Red Hat Enterprise Linux Virtualization (KVM)
- Red Hat OpenStack Platform
- VMware vSphere
- Microsoft Hyper-V
1.1. Host-based Subscriptions
Virtual machines can use host-based subscriptions instead of consuming entitlements from physical subscriptions. A host-based subscription is attached to a hypervisor and entitles it to provide subscriptions to its virtual machines. Many host-based subscriptions provide entitlements for unlimited virtual machines.
To allow virtual machines to inherit subscriptions from their hypervisors, you must install and configure virt-who. Virt-who queries the virtualization platform and reports hypervisor and virtual machine information to Red Hat Satellite.
When a virtual machine is registered with an activation key that has no subscriptions attached and auto-attach set to
true, and sufficient host-based subscriptions are available, one of the following behaviors occurs:
- If the virtual machine has been reported by virt-who and a host-based subscription is attached to the hypervisor, the virtual machine inherits a subscription from the hypervisor.
- If the virtual machine has been reported by virt-who, and the hypervisor is registered to Satellite but does not have a host-based subscription attached, a host-based subscription is attached to the hypervisor and inherited by the virtual machine.
- If the virtual machine, or its hypervisor, has not been reported by virt-who, Satellite grants the virtual machine a temporary subscription, valid for up to seven days. After virt-who reports updated information, Satellite can determine which hypervisor the virtual machine is running on and attach a permanent subscription to the virtual machine.
If auto-attach is enabled, but virt-who is not running or there are no host-based subscriptions available, Satellite attaches physical subscriptions to the virtual machines instead, which might consume more entitlements than intended.
If auto-attach is not enabled, virtual machines cannot use host-based subscriptions.
To see if a subscription requires virt-who, in the Satellite web UI, navigate to Content > Subscriptions. If there is a tick in the Requires Virt-Who column, you must configure virt-who to use that subscription.
Virtual machine subscription process
This diagram shows the subscription workflow when a virtual machine has not yet been reported by virt-who:
Satellite provisions a virtual machine.
The virtual machine requests a subscription from Satellite Server.
Satellite Server grants the virtual machine a temporary subscription, valid for a maximum of seven days, while it determines which hypervisor the virtual machine belongs to.
Virt-who connects to the hypervisor or virtualization manager and requests information about its virtual machines.
The hypervisor or virtualization manager returns a list of its virtual machines to virt-who, including each UUID.
Virt-who reports the list of virtual machines and their hypervisors to Satellite Server.
Satellite Server attaches a permanent subscription to the virtual machine, if sufficient entitlements are available.
For more information about the Red Hat subscription model, see Introduction to Red Hat Subscription Management Workflows.
1.2. Configuration Overview
To allow virtual machines to inherit subscriptions from their hypervisors, complete the following steps:
- Import a Subscription Manifest that includes a host-based subscription into Satellite Server. For more information, see Importing a Subscription Manifest into Satellite Server in the Content Management Guide.
- Ensure you have sufficient entitlements for the host-based subscription to cover all of the hypervisors you plan to use.
- If you are using Microsoft Hyper-V, enable remote management on the hypervisors.
Create a user with read-only access and a non-expiring password on each hypervisor or virtualization manager. Virt-who uses this account to retrieve the list of virtual machines to report to Satellite Server.
- For Red Hat products and Microsoft Hyper-V, create a virt-who user on each hypervisor that runs Red Hat Enterprise Linux virtual machines.
- For VMware vSphere, create a virt-who user on the vCenter Server. The virt-who user requires at least read-only access to all objects in the vCenter Data Center.
- Section 1.3, “Virt-who Configuration for Each Virtualization Platform”. Use the table in this section to plan how to configure and deploy virt-who for your virtualization platform.
- Chapter 2, Creating an Activation Key for Virtual Machines. Create an activation key with auto-attach enabled and no subscriptions attached.
- Chapter 3, Attaching a Host-based Subscription to Hypervisors. Attach a host-based subscription to all of the hypervisors you plan to use.
- Chapter 4, Creating a virt-who Configuration. Create a virt-who configuration for each hypervisor or virtualization manager.
- Chapter 5, Deploying a virt-who Configuration. Deploy the virt-who configurations using the scripts generated by Satellite.
- Chapter 6, Registering Virtual Machines to use a Host-based Subscription. Register the virtual machines using the auto-attach activation key.
1.3. Virt-who Configuration for Each Virtualization Platform
Virt-who is configured using files that specify details such as the virtualization type and the hypervisor or virtualization manager to query. The supported configuration is different for each virtualization platform.
Example virt-who configuration file
This example shows a virt-who configuration file created using the Satellite web UI or Hammer CLI:
[virt-who-config-1] type=libvirt hypervisor_id=hostname owner=Default_Organization env=Library server=hypervisor1.example.com username=virt_who_user encrypted_password=$cr_password rhsm_hostname=satellite.example.com rhsm_username=virt_who_reporter_1 rhsm_encrypted_password=$user_password rhsm_prefix=/rhsm
server values depend on the virtualization platform. The following table provides more detail.
username refers to a read-only user on the hypervisor or virtualization manager, which you must create before configuring virt-who. The
rhsm-username refers to an automatically generated user that only has permissions for virt-who reporting to Satellite Server.
Required configuration for each virtualization platform
Use this table to plan your virt-who configuration:
|Supported virtualization platform||Type specified in the configuration file||Server specified in the configuration file||Server where the configuration file is deployed|
Red Hat Virtualization
RHEL Virtualization (KVM)
Red Hat OpenStack Platform
Hypervisor (one file for each hypervisor)
Satellite Server, Capsule Server, or a dedicated RHEL server
Hyper-V hypervisor (one file for each hypervisor)
Satellite Server, Capsule Server, or a dedicated RHEL server
xen hypervisor types are not supported.
kubevirt hypervisor type is provided as a Technology Preview only.