There’s an old IT joke that the definition of ‘legacy’ is ‘anything that works.’ The applications running on the venerable IBM i midrange operating system are a case in point.
Even though this technology dates from the 1980s, a surprising number of midsize and large enterprises still run mission-critical apps on the platform. More surprising still, companies can now run those aging apps in the cloud – taking advantage of the benefits of cloud computing, including horizontal scale, automated management, and modern backup approaches.
There’s more to this story, however. How did a 1980s operating system become cloud compatible? And why should anyone care?
IBM i’s Secret Sauce
IBM i began its life in 1988 as the OS/400 operating system, which ran on IBM’s AS/400 midrange systems. Over the years, IBM rebranded the technology several times, from i5/OS to iSeries, and finally to IBM i.
Unlike many legacy operating systems that had their day in the sun, only to fade away as modernization efforts replaced them, IBM i has had remarkable staying power.
True, the stability and continued usefulness of applications on the platform are part of the reason. But there’s more to IBM i’s longevity than the applications themselves.
Back in the 1980s, the brilliant minds at IBM designed the original OS/400 to provide backward compatibility with older systems. The trick: IBM i programs contain both processor-independent virtual binary code as well as processor-dependent executable code.
The Java Virtual Machine (JVM) works in a similar fashion – and now, of course, JVM-style bytecode is a well-established pattern. But in 1988, Java was but a twinkle in its creators’ eyes, and OS/400’s virtual code trick was undoubtedly a precursor of the JVM.
In any case, this separation of virtual and executable code proved remarkably prescient, as it allows programs written for the operating system to move from one hardware platform to the next virtually unchanged – including hardware that wasn’t invented at the time programmers hammered out the code.
The Modern Context for IBM i
We might say the modern era for the IBM i platform began on April 2, 2008, when IBM launched its new Power Systems line of servers based on its POWER processors. IBM i was now able to run on a modern server platform, both on-premises and – at least in theory – in the cloud.
The IBM Cloud features Power Systems to be sure. Just one problem (or actually, a family of problems): migrating legacy apps to the cloud is easier said than done.
There are a number of reasons why migration is such a challenge. Remember, many IBM i applications date from the 1980s or early 1990s – before businesses used the Internet at all. As a result, many of the basic Internet-based protocols, capabilities, and utilities we now take for granted are not supported by such apps.
Added to this challenge are the terminal-based ‘green screen’ user interfaces that most IBM i applications require. Under the covers, the operating system and the terminals exchange proprietary legacy bitstreams – protocols alien to the modern cloud.
Nevertheless, many organizations that depend on their IBM i applications aren’t ready to retire them. Cloud migration may be the primary requirement for extending their life for years to come.
Skytap’s Legacy-as-a-Service
To address the cloud migration needs of IBM i customers (as well as companies running on any POWER-compatible operating system, including AIX), Skytap offers a self-service, multi-tenant public cloud service running on Power Systems.
In Skytap, customers can create environments that replicate how IBM i applications run in the data center, right down to low-level network addresses. A range of options help customers understand their application portfolio and migrate out of the data center.
Tools include Skytap’s advanced import application, ship-a-disk service and supported partner solutions like HelpSystems Robot HA. In addition, Skytap provides a full slate of migration tools and utilities. For example, the Skytap cloud includes support for the IBM i Access – Client Solutions and IBM Navigator for IBM i administrator tools.
Skytap also has backup and recovery covered by supporting IBM Backup, Recovery & Media Services (BRMS) for IBM i. BRMS works in conjunction with IBM Cloud Storage Solutions for IBM i, facilitating the use of the cloud for backup and storage. The result: tape drives and cartridges – and the need to FedEx them from place to place – are now headaches of the past.
Finally, Skytap’s intuitive user interface unlocks IBM i green screen in the cloud. From the user interface to the network interface, the apps look and operate following fully modern protocols on the outside, while on the inside the app is running just as it always has. Green screen technology is no match for Skytap’s emulation.
The Intellyx Take
The original AS/400 systems were boxes as large as dog houses – for large dogs. Today, Skytap can run dozens of instances of IBM i on POWER chips in a single 2U box, far faster than the programmers of the apps could imagine.
However, it’s important to keep in mind that Skytap’s Legacy-as-a-Service is more than a ‘lift and shift’ strategy. Today, organizations enjoy the luxury of many legacy modernization options as they leverage modern technology to update some software while moving other code to the cloud. The magic of Skytap is bringing legacy and modern closer together in the cloud. By moving older workloads to Skytap, businesses can modernize by leveraging cloud efficiencies and integrating cloud native services. Skytap is already available in IBM Cloud and is hinting strongly that more public clouds are on the way. Adding an analytics back-end or a new container based front-end to a battle-hardened IBM i system of record, all running in the cloud, is within reach.
With the help of Skytap partners like ARCAD Software, organizations that still depend on IBM i applications can automate builds, implement continuous testing, and leverage automation for continuous delivery – thus bringing this 1980s technology, not only to the cloud, but to the world of DevOps as well.
Copyright © Intellyx LLC. IBM and Skytap are Intellyx customers. None of the other organizations mentioned in this article are Intellyx customers. Image credit: Ya, saya inBaliTimur.
