February 4, 2019

In the past, if your business needed a mainframe, on-premises or outsourcing providers were your alternatives.  This meant that your company or the outsourcing provider was responsible for maintenance, backup, programming, and troubleshooting. Today, technologies have advanced to a place where you have additional options for your mainframe workloads.

With PSR Infrastructure Services, you have the option to host your mainframe environment at one of our data centers.  You can take advantage of benefits such as economy of scale on hardware, software, and disaster recovery.

To help you decide which option is best for your organization, this article will compare on-premises mainframes with PSR Infrastructure as a Service.


With mainframe infrastructure, there are serious financial and management considerations, especially in regard to backup and recovery. For example, with an on-premises solution, you are responsible for providing facilities, heating/cooling, power, and management for a dedicated server, storage, and tape subsystem that includes a backup generator and disaster recovery site.


An on-premises solution gives you local control over your workloads, applications, and environments. However, with great control comes great responsibility. If you decide to run your mainframe on-premises, you are responsible for every aspect of its infrastructure, including backup and recovery, local network connections to non-mainframe systems, software management and programming, architecture, and maintenance.


With IaaS for your mainframe workloads, you can benefit from economies of scale on the infrastructure, software, maintenance, and disaster recovery. For example, you have the choice of either dedicated or shared mainframe-server space, based on your needs.  Many times, the decision to utilize a shared or dedicated environment comes down to ISV software licensing requirements.   The service provider is available to manage the infrastructure requirements.  Systems management and operations of the system can remain with the client.


The cost of technology is another consideration in the comparison between on-premises and IaaS. There are two ways to pay for technology: as a capital expenditure or as an operating expense.


With an on-premises mainframe, you will most likely pay for infrastructure, software, and services with a combination of capital and operating expenditures. Any equipment for networking, backup, and the mainframe itself would be a capital expenditure (CapEx), and any monthly services, such as monitoring, security, or software applications, would be an operating expense (OpEx).


If you choose IaaS for your mainframe workloads, you can move expenses related to your mainframe to the OpEx column. In other words, you can purchase your mainframe infrastructure from PSR like you buy utilities: at a set, monthly cost. This means, you can pay for CPU compute, storage, and disaster recovery as an operating expense. Plus, you can use our backup and recovery network infrastructure, which includes data replication to a remote facility with capabilities to restore the system in the event of a disaster.


Buying storage technology is both an art and a science. Buy too much and you run the risk of overspending on storage and wasting resources such as utilities and maintenance costs on unused capacity. If you buy less than you need, though, you’ll run the risk of losing important data or overwhelming your infrastructure and causing delays.  With IaaS, additional storage can be provisioned as needed eliminating the need for time consuming and capital-intensive upgrades.


With a local mainframe, you might be able to increase your capacity for sudden or temporary spikes. It all depends on your equipment currency.


With infrastructure as a service, you can increase capacity at any time to handle temporary spikes in traffic and business growth. The flexibility of IaaS can provide the ability to change capacity whenever your business needs change, which makes capacity planning easy. Also, you only pay for the capacity you actually use, which is an efficient use of your technology budget.

Programming and Licensing

It’s the software and applications on a mainframe that create business value. With IBM and ISV software come considerations such as licensing management and programming.


If you have a local mainframe, then you have the ability to manage various versions of IBM and ISV software and enterprise license agreements (ELAs). Plus, you’ll be able to use your own resources to handle any systems programming needs.


Most software vendors provide flexibility with respect to utilizing licenses on a hosted mainframe, however, given contractual requirements by software providers, every situation needs to be carefully evaluated to ensure compliance is maintained.   If you contract with PSR for mainframe hosting, we can provide systems programming services for IBM and ISV software, upon request. Plus, we can handle the management of software and ELAs and free you from that responsibility.

Backup and Recovery

Because your most important, mission-critical applications reside on your mainframe, backup and recovery is an important consideration. If you want to create a complete disaster recovery solution for your mainframe, you’ll need to either back up your data to a second site or create an off-site data storage solution.


For a local mainframe, you’ll need to provide management and facilities for backup and recovery, including dedicated server, storage, and tape subsystem, complete with backup generator at a secondary data center. For many companies, this kind of backup solution is too expensive to make business sense creating risk with this important data.


If you choose PSR for IaaS, you can benefit from our establish disaster recovery infrastructure, which includes a backup facility, infrastructure, and network for data replication that is out of the region and set up to restore systems if there is a disaster.   We can also provide resources to test your disaster recovery plan and establish documented procedures in the event a disaster occurs.

The Conundrum of Freedom vs. Control

One key reason many companies keep their mainframes on-premises is so they can maintain local control over aspects such as architecture, software and hardware maintenance windows, and operational production. With IaaS from PSR, you can maintain control over your mainframe environment as if it were located on your site. Plus, we’ll take on as much or as little responsibility as you need. PSR can handle routine maintenance, such as software updates, for example. We work with you to develop a solution that meets your specific needs.

Learn more about the business benefits of IaaS for your mainframe environment. Speak with a PSR technical expert today.