Mainframe Application Modernization with IBM Cloud and IBM zSystems

6 min read

Exploring a hybrid cloud strategy that includes IBM zSystems and IBM Cloud.

Digital transformation initiatives sweeping across industries like banking, insurance, healthcare, government and retail are driven by new consumer behavior, new regulations and a new way of doing business. Additionally, initiatives like open banking, open insurance and open data (among others) have the potential to create new revenue channels.

In many enterprises, mission-critical applications and core business transactions have been running successfully on IBM zSystems for years, if not decades. With enterprises globally looking to reduce time to market and increase their ability to respond quickly to market changes, it is time to look at embracing mainframe application modernization as part of the overall digital transformation agenda.

To retain the core strengths and attributes of IBM's mainframe platform and leverage the performance, resiliency, security and regulatory compliance programs of IBM Cloud, a hybrid cloud approach can help enterprises on their mainframe application modernization journeys. 

A hybrid cloud strategy that includes IBM zSystems and IBM Cloud offers many benefits, including innovative development practices that leverage an agile integrated DevOps approach, easier access to mainframe applications and data, the ability to address skills gaps with open tooling, and IT automation capabilities. IBM Cloud is designed for enterprise and regulated applications and offers innovative cloud security capabilities, such as confidential computing services and native zSystems dev/test support. Together, IBM Cloud and zSystems can help accelerate mainframe application modernization to improve agility, optimize costs and lower risk.

A tale of two teams

To run core business transactions on IBM zSystems, there is traditionally a dedicated development and operations team to support these applications, with the responsibility to run the day-to-day operations.

Apart from the above mainframe team, many enterprises now have a digital team under a Chief Digital Officer (CDO) to onboard new cloud-native technologies, tools and processes and help improve business agility, developer velocity and spur innovation through adoption of newer compute models — like the hybrid cloud deployment model.

Our objective is to help clients leverage IBM Cloud and zSystems together in a hybrid approach to do the following:

  • Show how organizations can come together to deliver transformation while continuing to run the business successfully.
  • Address challenges expressed by industry leaders while embarking on the mainframe application modernization journey.
  • Guide clients and partners through various solution architectures and best practices.
  • Demonstrate how to drive a common enterprise modernization approach across the organization.

Mainframe application modernization with IBM Cloud can be achieved in various dimensions; in this post, we will talk about the following:

  1. Improve business agility and provide a modern DevOps platform for mainframe applications with IBM Cloud.
  2. Secure mainframe applications and data in a hybrid multicloud platform.
  3. Simplify access to mainframe applications with an API strategy.
  4. Achieve greater sustainability with IBM LinuxONE and IBM Cloud.

1. Improve business agility and provide a modern DevOps platform for mainframe applications with IBM Cloud

IBM zSystems supports the latest development, operational tools and processes and features z/OS dev and test through IBM Wazi as a Service. IBM Cloud offers a fully functional mainframe through a high-performing IBM Z compute Virtual Server Instance (VSI) in IBM Cloud Virtual Private Cloud (VPC) that can be integrated with modern DevOps toolchains with built-in security and compliance features. It helps remove skills barriers, eliminates contention between multiple teams sharing on-premises-based IBM Z LPAR and spurs innovation in mainframe application development and test processes.

Enterprise DevOps solution architectures can be implemented on IBM Cloud to help set up an integrated DevOps pipeline suitable for both cloud-native distributed and mainframe applications. They can take advantage of many cloud services—like data and AI—to modernize mainframe applications. The security and compliance services available in IBM Cloud can protect and validate mainframe applications and data during the development phase.

Get started with a z/OS dev and test virtual server on IBM Cloud in under six minutes [1]

Enable continuous testing with an IBM zSystem in IBM Cloud that performs up to 15x faster [2]

2. Secure mainframe applications and data in a hybrid cloud platform

Application and data running on the IBM zSystems platform are often mission-critical to the business, and they require the highest levels of security available. As public cloud applications increasingly need to access mainframe applications and data, the expectation is for the same level of enterprise-grade security across a hybrid multicloud platform.

IBM Cloud is designed for enterprise and regulated workloads and has developed many security services based on IBM Z platform security features to support both IBM Cloud’s own platform architecture and offered as cloud services to clients. IBM Cloud Hyper Protect Crypto Services manages client in IBM Cloud, and it is FIPS 140-2 Level 4 certified, which is the industry’s highest certification for a Hardware Security Module (HSM) [3]. With the functionality of Keep Your Own Key (KYOK), even IBM Cloud administrators cannot access the keys; they are solely owned and managed by the clients, to help them protect sensitive mainframe assets in Cloud.

IBM Cloud’s security services can also be extended to hybrid-cloud-centric enterprise workloads through the Unified Key Orchestrator.

3. Simplify access to mainframe applications with an API strategy

An API-centric integration strategy is fundamental to mainframe application modernization. New cloud-native channel applications need access to mainframe applications and data, which hosts core business logic for many industries. The core mainframe applications like COBOL, CICS and IMS can be exposed through APIs. IBM Cloud offers a secure framework to manage the lifecycle of mainframe APIs for development and test through hybrid cloud. This is supported by the IBM Z and Cloud Modernization Stack running on IBM Cloud.

With a high-performing z/OS VSI provisioned in IBM Cloud VPC and integrated with CI/CD pipelines, IBM Cloud can provide a secure development and test environment to create new IBM Z-centric APIs, and it can use IBM Cloud for Financial Services features like the IBM Cloud Security and Compliance Center to validate the compliance requirements.

4. Achieve greater sustainability with IBM LinuxONE and IBM Cloud

Digital transformation continues to drive additional compute capacity, putting pressure on an organization’s sustainability objectives. Measuring carbon footprint through server and cloud-centric calculators and finding ways to reduce the footprint across the board is a key priority not only for cloud vendors, but also for enterprises. A focus on exploiting clean energy sources with efficient hardware and software technologies is becoming part of standard corporate responsibility. IBM Cloud offers IBM LinuxONE servers in their data centers to help reduce the carbon footprint and reduce the energy costs. An IBM LinuxONE server can save, on average, 59% per year in power consumption when compared to x86 systems running workloads with the same throughput.

Leverage the expertise of IBM Consulting

IBM Consulting offers a broad array of expertise to help our clients maximize value from their application investments and accelerate IBM zSystems and hybrid cloud modernization initiatives, including the solution architectures referenced here and many other zSystems modernization patterns.


To protect clients’ investments and help accelerate their digital transformation journey, IBM Cloud provides a set of hybrid solution architectures that will help remove the inhibitors in modernizing mainframe workloads.

IBM recommends a hybrid cloud approach to mainframe modernization, with IBM zSystems and IBM Cloud working together with seamless integration architectures. The four solution architectures described in this blog will help improve business agility, reduce time to market and help modernize development through an enterprise DevOps approach, help address sustainability challenges, address enterprise security concerns of hybrid multicloud platform, and help integrate cloud-native applications with mainframe applications.

Additional solution architectures around data and AI, IBM Cloud for Financial Services, refactoring mainframe applications, etc., will be discussed in future blog posts to give more guidance around mainframe application modernization through hybrid cloud.

Contact IBM Cloud Expert Labs for more implementation details or schedule a free consulting session with an IBM Consulting Expert.


[1] On average, creating an experimental IBM Cloud z/OS Virtual Server Instance (VSI) of a z/OS 2.4 stock image and a mz2o-2x16 VSI profile takes 1 minute, and it is ready for user login (SSH) in 5.5 minutes. Disclaimer: Measurements were done across two different IBM Cloud production sites using an experimental version of z/OS 2.4 stock image and a mz2o-2x16 VSI profile. Measurements were performed with Ansible automation based on the examples here. Results may vary.

[2] Applications compile faster on an experimental IBM Cloud z/OS Virtual Server Instance (VSI) than on IBM Z Development and Test (ZD&T) EE V13.3 running on the compared IBM Cloud x86 VSI — about 15x faster compilation of Java applications, about 12x faster compilation of C applications and about 8x faster batch compilations of COBOL/FORTRAN applications. Disclaimer: Performance results based on IBM internal tests running application compiles on an experimental IBM Cloud z/OS V2R4 Virtual Server Instance (VSI) with profile mz2o-2x16 versus on IBM ZD&T EE V13.3 running in an IBM Cloud x86 VSI with profile mx2-2x16. IBM ZD&T was running on Ubuntu 20.4 on a x86 Production VSI with a Cascade Lake Intel Xeon Platinum CPU @ 2.4GHz. Both z/OS VSI and ZD&T were configured with 2 vCPUs, 16GB memory, and 1 TB Block storage with 10 IOPS/GB. The following applications were compiled — a Java application that processes SMF records, a C application that processes IBM Z hardware diagnostic data, a COBOL application that creates and updates records on a file and a FORTRAN statistical application. Results may vary.

[3] Data security through the industry’s only FIPS 140-2 Level 4 HSMs protects data in IBM Cloud:

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