Chapter 1. Introducing RHEL on public cloud platforms

Public cloud platforms provide computing resources as a service. Instead of using on-premises hardware, you can run your IT workloads, including Red Hat Enterprise Linux (RHEL) systems, as public cloud instances.

To learn more about RHEL on public cloud platforms, see:

1.1. Benefits of using RHEL in a public cloud

RHEL as a cloud instance located on a public cloud platform has the following benefits over RHEL on-premises physical systems or virtual machines (VMs):

  • Flexible and fine-grained allocation of resources

    A cloud instance of RHEL runs as a VM on a cloud platform, which typically means a cluster of remote servers maintained by the provider of the cloud service. Therefore, allocating hardware resources to the instance, such as a specific type of CPU or storage, happens on the software level and is easily customizable.

    In comparison to a local RHEL system, you are also not limited by the capabilities of your physical host. Instead, you can choose from a variety of features, based on selection offered by the cloud provider.

  • Space and cost efficiency

    You do not need to own any on-premises servers to host your cloud workloads. This avoids the space, power, and maintenance requirements associated with physical hardware.

    Instead, on public cloud platforms, you pay the cloud provider directly for using a cloud instance. The cost is typically based on the hardware allocated to the instance and the time you spend using it. Therefore, you can optimize your costs based on your requirements.

  • Software-controlled configurations

    The entire configuration of a cloud instance is saved as data on the cloud platform, and is controlled by software. Therefore, you can easily create, remove, clone, or migrate the instance. A cloud instance is also operated remotely in a cloud provider console and is connected to remote storage by default.

    In addition, you can back up the current state of a cloud instance as a snapshot at any time. Afterwards, you can load the snapshot to restore the instance to the saved state.

  • Separation from the host and software compatibility

    Similarly to a local VM, the RHEL guest operating system on a cloud instance runs on a virtualized kernel. This kernel is separate from the host operating system and from the client system that you use to connect to the instance.

    Therefore, any operating system can be installed on the cloud instance. This means that on a RHEL public cloud instance, you can run RHEL-specific applications that cannot be used on your local operating system.

    In addition, even if the operating system of the instance becomes unstable or is compromised, your client system is not affected in any way.

1.2. Public cloud use cases for RHEL

Deploying on a public cloud provides many benefits, but might not be the most efficient solution in every scenario. If you are evaluating whether to migrate your RHEL deployments to the public cloud, consider whether your use case will benefit from the advantages of the public cloud.

Beneficial use cases

  • Deploying public cloud instances is very effective for flexibly increasing and decreasing the active computing power of your deployments, also known as scaling up and scaling down. Therefore, using RHEL on public cloud is recommended in the following scenarios:

    • Clusters with high peak workloads and low general performance requirements. Scaling up and down based on your demands can be highly efficient in terms of resource costs.
    • Quickly setting up or expanding your clusters. This avoids high upfront costs of setting up local servers.
  • Cloud instances are not affected by what happens in your local environment. Therefore, you can use them for backup and disaster recovery.

Potentially problematic use cases

  • You are running an existing environment that cannot be adjusted. Customizing a cloud instance to fit the specific needs of an existing deployment may not be cost-effective in comparison with your current host platform.
  • You are operating with a hard limit on your budget. Maintaining your deployment in a local data center typically provides less flexibility but more control over the maximum resource costs than the public cloud does.

1.3. Frequent concerns when migrating to a public cloud

Moving your RHEL workloads from a local environment to a public cloud platform might raise concerns about the changes involved. The following are the most commonly asked questions.

Will my RHEL work differently as a cloud instance than as a local virtual machine?

In most respects, RHEL instances on a public cloud platform work the same as RHEL virtual machines on a local host, such as an on-premises server. Notable exceptions include:

  • Instead of private orchestration interfaces, public cloud instances use provider-specific console interfaces for managing your cloud resources.
  • Certain features, such as nested virtualization, may not work correctly. If a specific feature is critical for your deployment, check the feature’s compatibility in advance with your chosen public cloud provider.

Will my data stay safe in a public cloud as opposed to a local server?

The data in your RHEL cloud instances is in your ownership, and your public cloud provider does not have any access to it. In addition, major cloud providers support data encryption in transit, which improves the security of data when migrating your virtual machines to the public cloud.

The general security of your RHEL public cloud instances is managed as follows:

  • Your public cloud provider is responsible for the security of the cloud hypervisor
  • Red Hat provides the security features of the RHEL guest operating systems in your instances
  • You manage the specific security settings and practices in your cloud infrastructure

What effect does my geographic region have on the functionality of RHEL public cloud instances?

You can use RHEL instances on a public cloud platform regardless of your geographical location. Therefore, you can run your instances in the same region as your on-premises server.

However, hosting your instances in a physically distant region might cause high latency when operating them. In addition, depending on the public cloud provider, certain regions may provide additional features or be more cost-efficient. Before creating your RHEL instances, review the properties of the hosting regions available for your chosen cloud provider.

1.4. Obtaining RHEL for public cloud deployments

To deploy a RHEL system in a public cloud environment:

  1. Select the optimal cloud provider for your use case, based on your requirements and the current offer on the market.

    The cloud providers currently certified for running RHEL instances are:

  2. Create a RHEL cloud instance on your chosen cloud platform. For more information, see Methods for creating RHEL cloud instances.
  3. To keep your RHEL deployment up-to-date, use Red Hat Update Infrastructure (RHUI).

1.5. Methods for creating RHEL cloud instances

To deploy a RHEL instance on a public cloud platform, you can use one of the following methods:

Create a system image of RHEL and import it to the cloud platform.

  • To create the system image, you can use the RHEL image builder or you can build the image manually.
  • This method uses your existing RHEL subscription, and is also referred to as bring your own subscription (BYOS).
  • You pre-pay a yearly subscription, and you can use your Red Hat customer discount.
  • Your customer service is provided by Red Hat.
  • For creating multiple images effectively, you can use the cloud-init tool.

Purchase a RHEL instance directly from the cloud provider marketplace.

  • You post-pay an hourly rate for using the service. Therefore, this method is also referred to as pay as you go (PAYG).
  • Your customer service is provided by the cloud platform provider.
Note

For detailed instructions on using various methods to deploy RHEL instances On Microsoft Azure, see the following chapters in this document.