Red Hat OpenShift Virtualization on IBM Z and LinuxOne: bridging VMs and containers

Imagine running your traditional virtual machines (VMs) and modern containerized applications side by side on the same platform, managed through one unified system. Red Hat OpenShift Virtualization now makes this possible on IBM Z and IBM LinuxOne, IBM’s enterprise server platforms. This combination means organizations can modernize at their own pace, bridging legacy and cloud-native workloads. OpenShift Virtualization is available on other platforms, such as x86, as well, but its arrival on IBM Z and IBM LinuxONE brings new options to businesses already running critical workloads on mainframe systems.

With the release of OpenShift Virtualization 4.18 as a tech preview on IBM Z and IBM LinuxONE, organizations can now run and manage KVM-based VMs (built for the s390x architecture) alongside containers in the same OpenShift cluster. The OpenShift Virtualization operator installs directly on an existing OpenShift 4.18 cluster running on logical partitions (LPARs), with no need for separate hypervisor software. This unified setup means teams can orchestrate VMs and containers through the same OpenShift UI and CLI, using familiar tools like OperatorHub, integrated monitoring, and logging, including IBM Fusion Data Foundation.

The solution supports key features such as high availability at the pod level and live guest migration within the same cluster. It also integrates with common templates and prebuilt guest images (e.g., RHEL 8, 9, 10 beta) to simplify deployment.

OpenShift Virtualization on IBM Z and IBM LinuxONE reflects IBM’s continued investment in making its enterprise systems part of its modern hybrid cloud strategies, combining reliability and performance with the flexibility of Kubernetes-native operations.

What is OpenShift Virtualization (and why does it matter)?

OpenShift Virtualization is a feature in OpenShift that integrates VMs into a Kubernetes-based environment. This matters because many organizations still rely on VMs for certain workloads, yet want the agility and speed of a cloud-native infrastructure. OpenShift Virtualization (built on the KubeVirt project and using the trusted KVM hypervisor) provides a way to run VMs within OpenShift, so teams can use the same platform and tools for both traditional VM-based applications and new containerized applications. In practice, virtualization administrators can manage their VMs in ways similar to what they are used to with their existing or previous traditional virtualization platform, which is in parallel to container administrators and developers who use the same platform for their respective workloads and tasks. This means no more disparate infrastructures for VMs and containers.

Key capabilities of OpenShift Virtualization include:

• Unified management: Administer VMs and containers through a single Kubernetes-native control plane. This simplifies operations with a single platform for VMs and containers, allowing you to standardize infrastructure deployment and maintain all workloads using a standard common set of enterprise tools and a single management interface that is customized for virtualization administrators, container or Kubernetes administrators, and application developers.
• Modernization path: It offers a clear path to modernize or gradually containerize legacy applications. You can containerize some components while keeping others as VMs. This provides a path to infrastructure modernization and expedites the modernization of VM-based applications, preparing for future cloud-native or AI investments.
• Faster delivery: Developers and IT teams benefit from self-service provisioning and consistent CI/CD processes for both VMs and containers. With one platform, they can build, test and deploy faster, which means accelerating time to market for new features.
• No application left behind: Perhaps most importantly, OpenShift Virtualization can help eliminate fragmented operations , reduce complexity and accelerate modernization by unifying VMs and cloud-native containers in a single environment. In other words, an enterprise can move toward cloud-native practices without leaving its critical legacy applications behind. 

In summary, OpenShift Virtualization brings the benefits of cloud platforms to traditional workloads. It’s a bridge between the old and the new, allowing an organization to manage both in one place until they’re ready to modernize completely (if ever).

IBM Z and IBM LinuxONE:  modern enterprise server platforms

IBM Z and IBM LinuxONE are famous for their reliability, security and massive processing power. IBM Z and IBM LinuxONE have continually evolved into a modern infrastructure platform used by major industries worldwide. For instance, 67 of the Fortune 100 companies look to IBM Z to run their IT environments. These systems handle staggering workloads–an estimated 30 billion business transactions every day, including the majority of credit-card transactions globally. Modern models like the IBM z17 and IBM LinuxONE 5 provide:

• Extreme performance and scalability: IBM Z can run at high utilization (near 100%) without performance degradation. It’s designed for high throughput–processing millions of transactions per second–with hardware features like on-chip accelerators (for AI, encryption, etc.). Organizations can scale on a single system with the ability to add capacity on demand, growing processing power with minimal impact on energy usage, floor space and staffing. In essence, one IBM Z machine can replace racks of distributed servers, which saves on datacenter space and power.
• Reliability and availability: Enterprise systems are built for critical uptime. IBM Z and IBM LinuxONE are designed for extremely high availability (often cited as “eight nines” or 99.999999% uptime), with redundancy and fail-safes. This makes it ideal for banking, insurance, government and other sectors where downtime is not an option.
• Security: Security is baked into IBM Z and IBM LinuxONE. Features like pervasive encryption (encrypting data in memory and in transit automatically) and hardware security modules mean that sensitive workloads are well-protected. IBM Z and IBM LinuxONE systems offer certified multitenant isolation and even quantum-safe cryptography for future-ready security.
• Modern flexibility: Importantly, IBM Z is not a closed legacy box. It runs modern Linux distributions (e.g., RHEL, SUSE Ubuntu, etc.), cloud software and open source tooling. It has embraced hybrid cloud by working in tandem with cloud platforms and by supporting technologies like Kubernetes and OpenShift. IBM Z and IBM LinuxONE are part of many companies’ hybrid IT strategy, bringing together the best of cloud and enterprise servers in a modernized IT infrastructure.

In short, IBM Z and IBM LinuxONE today are powerful, cloud-friendly systems known for their unbeatable combination of throughput, security and reliability. This makes them an excellent host for OpenShift and its Virtualization capabilities. With IBM Z and IBM LinuxONE, you get the performance of an enterprise server and the flexibility of cloud architecture in one platform.

OpenShift Virtualization on IBM Z and IBM LinuxONE: VMs and containers together

So what does it mean that OpenShift Virtualization is now available on IBM Z? Essentially, you can run OpenShift on an IBM Z or IBM LinuxONE system and enable the OpenShift Virtualization operator to start running VMs inside that OpenShift cluster. IBM and Red Hat have worked together so that this feature,  initially available on x86 hardware, is now supported on the IBM Z and IBM LinuxONE architecture (s390x). As of now, it’s available as a Technology Preview, running on OpenShift 4.18 clusters deployed in LPARs using the KVM hypervisor with a target to GA in the upcoming OpenShift release (4.19).

How it works: IBM Z and IBM LinuxONE support a virtualization technology and type 1 hypervisor called Kernel-based Virtual Machine (KVM) on Linux. OpenShift Virtualization relies on KVM (via KubeVirt) to deploy VM instances on cluster nodes. On IBM Z and IBM LinuxONE, the OpenShift cluster typically runs on single (i.e., single node OpenShift) or multiple (i.e., multiple nodes) LPARs (Logical Partition), with OpenShift Virtualization managing KVM guests on nodes being deployed on an LPAR without needing a separate hypervisor installation. The OpenShift Virtualization operator for IBM Z and IBM LinuxONE can be installed through OperatorHub on OpenShift 4.18 (or later).

A few points to note about OpenShift Virtualization on IBM Z:

• It manages KVM-based VMs on IBM Z and IBM LinuxONE. Other hypervisors like IBM z/VM are outside its scope. So, it’s about running Linux VMs on IBM Z alongside containers, all orchestrated by OpenShift.
• These VMs must be for the s390x architecture (the CPU architecture used in IBM Z and IBM LinuxONE). In practice, that means you’d be running only Linux VMs (since Linux distributions for IBM Z are compiled for s390x). Windows VMs wouldn’t apply here since there is no Windows natively on IBM Z and IBM LinuxONE available. In addition, zOS is also unable to run in KVM-powered VMs.
• OpenShift provides the same familiar interfaces to create and manage VMs: you can use the OpenShift web console or oc CLI to define a VM (with YAML, similar to a pod definition). You get features like virtual networks and storage for VMs. The integration includes storage management (using FDF/ODF or local storage), software-defined networking for VMs, as well as logging and monitoring for the VMs, just like for containers. Essentially, your operations team can monitor the health and performance of both VMs and containers side by side in a single dashboard.
• OpenShift Virtualization on IBM Z and IBM LinuxONE offers several features that contribute to workload resilience. For VMs, this includes live guest migration, allowing a running VM to move between nodes within the cluster for proactive maintenance without interrupting service. While automatic recovery of VMs from a sudden node failure currently requires manual administrator intervention on the s390x architecture, the underlying IBM Z and IBM LinuxONE platform provides exceptional enterprise server reliability, contributing to overall system stability for your virtualized workloads.
• No need for separate management tools. Previously, 1 team might manage VMs via plain KVM or z/VM and another team might manage containers with Kubernetes or other container orchestration platforms. Now, a unified platform can do both. This drastically simplifies skill requirements and processes. IT staff can take advantage of their existing OpenShift/Kubernetes skills to manage VMs on IBM Z or IBM LinuxONE; and conversely, mainframe teams can expose some of their workloads through a more cloud-like interface. As Red Hat’s datasheet notes, this is especially beneficial for users who can reuse their KVM skills, either when migrating onto IBM Z or IBM LinuxONE from an x86 environment or when modernizing colocated applications. In other words, if you know KVM or OpenShift on x86, you can apply that knowledge on IBM Z and IBM LinuxONE, as well.

The result is a single, powerful platform: IBM Z or IBM LinuxONE running OpenShift with Virtualization means you have one physical system handling both modern containerized applications and traditional VM applications. This opens up significant opportunities to consolidate and streamline your IT environment.

Real-world benefits and value points

Running OpenShift Virtualization on IBM Z or IBM LinuxONE offers real business and operational benefits. Let’s highlight a few key value points with actual scenarios:

Cost savings through consolidation: By colocating workloads, organizations can save money on infrastructure and licensing. IBM Z is an extremely dense and efficient platform. You can consolidate many distributed x86 servers’ workloads onto a single mainframe. This means savings in power, cooling and floor space, as well as potentially fewer software licenses. As one Red Hat resource notes, with IBM Z organizations can scale on a single system with on-demand capacity, with minimal impact on energy usage, floor space and staffing. 

Scenario: A bank has dozens of x86 servers running various VMs for core banking applications. By moving these into OpenShift Virtualization on an IBM Z (which they already use for other critical workloads), they reduce their datacenter footprint and energy bill. The hardware investment in IBM Z is offset by eliminating many smaller servers. Over time, they also save on operational overhead since there’s only 1 system to manage and maintain, rather than many scattered ones.

Operational efficiency and simplified management: Having a single, unified platform means your operations are much simpler. Instead of separate teams or processes for “VM infrastructure” and “container platform,” you have a common set of tools and a single pane of glass for management. This centralized management leads to consistent policies, easier automation and less context-switching for staff. 

Scenario: An IT operations team currently uses KVM for VMs. With OpenShift Virtualization on IBM Z, they migrate VMs into OpenShift. Now they use Kubernetes-native automation (i.e., operators, GitOps) to manage updates and configuration for both VMs and containers. The team no longer juggles 2 completely different environments, which reduces errors and speeds up tasks. Monitoring and logging are unified–an operator can use 1 dashboard to see all workloads' health. This efficiency can also translate into faster time to market for new initiatives because the processes to provision and deploy are streamlined for all application types.

Bridging legacy and modern applications: Perhaps the biggest strategic benefit is the ability to modernize gradually without “big bang” migrations. Because IBM Z often hosts critical legacy systems (e.g., a COBOL banking application on z/OS or a critical database on Linux), rewriting or moving these systems is risky and costly. OpenShift on IBM Z allows companies to bring modern applications closer to the data and functions on the mainframe. 

Scenario: An insurance company has a policy management system running on IBM Z (z/OS). They want to create a new web front end and mobile application. Instead of moving the policy system off the mainframe, they use OpenShift on IBM Z to host new microservices that interface with it. These microservices (running as containers) live on the same physical machine, so they have fast, security-focused access to the legacy system. At the same time, if needed, the team could also run Linux VMs for any components that are not yet containerized. The result is a hybrid environment where legacy and modern applications work together efficiently–customers get a modern experience, and IT doesn't have to rewrite the entire legacy system. This bridging of old and new protects existing investments while enabling innovation.

Improved resource utilization and performance: Mainframes are built to be efficient with large workloads. By bringing VMs onto IBM Z or IBM LinuxONE, you can often run them at higher utilization than on distributed servers. Also, having everything on 1 platform can reduce network overhead (less data transfer between systems) and improve performance for composite workloads. For example, if a containerized application and a VM are exchanging data, doing so within the same IBM Z or IBM LinuxONE server (possibly even within the same memory if optimized) is faster than sending data across a network to a different machine. IBM’s Redbook on OpenShift on Z notes that network traffic is more predictable with less latency compared to x86 environments when everything is in 1 box. 

Scenario: A retail company runs an online store’s front end in containers and an inventory management system in a VM. On separate systems, every query from the front end to the inventory has to travel through network switches. After consolidating on OpenShift on IBM Z, those communications are internal, yielding quicker responses and a better customer experience. Additionally, the company can take advantage of IBM Z’s I/O to handle spikes (like Black Friday traffic) more gracefully than their previous distributed setup.

In all these scenarios, a common theme emerges: simplification, consolidation and optimization. By using OpenShift Virtualization on IBM Z or IBM LinuxONE, enterprises simplify their architecture (1 platform instead of many) and often gain performance or cost efficiencies by using the full capabilities of the mainframe. It’s about doing more with less and doing it in a controlled, consistent way.

Conclusion: bridging today’s needs with tomorrow’s innovations

The availability of Red Hat OpenShift Virtualization on IBM Z and IBM LinuxONE is an exciting development for IT organizations. It signals that even the most traditional infrastructure (i.e., the mainframe) is fully part of the hybrid cloud journey. With this capability, companies no longer have to choose between keeping critical workloads on IBM Z or joining the OpenShift/Kubernetes wave–they can do both and get the best of both worlds. As one IBM community article put it, OpenShift on Z brings modern application management and tools to VMs to expedite the modernization of existing applications, providing management efficiencies by monitoring the health and performance of VMs and containers side by side.

For IT professionals, this means you can:

• Run new cloud-native microservices applications alongside core VM-based business applications on the same reliable IBM Z system.
• Gradually modernize your estate, perhaps containerizing 1 component at a time, without disrupting what still reliably works.
• Use a single skill set and toolset (OpenShift) to manage a broad range of workloads, which can alleviate skills shortages and simplify operations.
• Assure your business that you are taking advantage of your past investments (in IBM Z and in virtualization) while also embracing modern, agile practices. 

OpenShift Virtualization on IBM Z and IBM LinuxONE helps organizations bridge traditional and modern IT in a practical, low-risk way. It brings cloud-like flexibility to one of the most powerful computing platforms available. The result is a unified environment where innovation can happen faster, all while maintaining the trust and performance that IBM Z systems have delivered for decades.

For further reading and detailed technical guidance, refer to the IBM announcement and documentation on OpenShift Virtualization for IBM Z and IBM LinuxONE and the Red Hat OpenShift 4.18 release notes that mentions IBM Z support. Embracing this new capability could be a key step in your hybrid cloud strategy, helping your IT deliver more value with less complexity.