Recently, one of LRS’ longtime IBM Z customers approached us with an interesting request: unplanned growth in their mainframe workloads meant they needed to upgrade their processor in a short timeframe. What’s more, this Midwest-based telecommunications billing services provider needed to keep the cutover time to a minimum. This customer runs z/VM, VSEⁿ and Linux connected to Flash Systems storage. Their question: could LRS help make this happen… sooner rather than later?
As is often the case with IBM Z environments, by staying current with all software versions and support levels, the customer is able to perform upgrades like these with only a change of hardware level. The upward compatibility of IBM Z enabled the customer to rapidly scale capacity and move to new hardware with minimal disruption, demonstrating the agility of the platform.
First Things First
The new hardware was ordered with a compatibility feature that allows the Worldwide Port Name (a unique identifier for Fibre Channel-attached ports) to be unchanged from the old system. This enabled Flash System and SAN connectivity to continue without changes to the SAN, since the hardware addresses of SAN components did not change. The more complicated alternative would have been to remap all the SAN connections involving the Z hardware, the SAN switches, and the Flash Systems, which can take significant time to perform.
Regarding the hardware upgrade, the customer was going from a z15 (rack mounted) to a z16 (customer-rack mounted) machine. Additional processors and capacity settings were needed for new sets of virtual VSE guests running under z/VM. Additionally, IBM provided Integrated Facility for Linux (IFL) engines to enable and encourage additional use of Linux in the environment for the future. A new IBM rack with appropriate Power Distribution Units (PDUs) and cables was also ordered to ensure no “gotchas” with a different customer-supplied rack.
Prior to installation, the customer ensured sufficient space for the rack, power and power receptacles as well as network connectivity to IBM, local DNS/NTP servers, and IP addresses for the new Hardware Management Appliance (HMA).
Making it Happen
The IBM team assembled the rack, placed the z16 into the rack, connected it to IBM, and transferred customizations from the existing z15 hardware to the new z16 machine. Together, all of these steps took only a day… which meant it was time for LRS to take the stage.
The next day, LRS arrived with our Quickstart services, enabling additional capabilities in the HMA, readying the OSA-based terminal controller for terminal access to the LPARs, and verifying readiness for migration. On the day of cutover, workload was brought down on the existing z15. Next, FCP and network cables were swung from the old box to the new and the workload was restarted. All of this involved less than an hour of downtime, most of which was spent verifying proper systems operation prior to turning the environment over to end users.
It should be noted that only one change was needed in the VSEⁿ environment, and that was to update the CPUID in library members $ASIPROC.PROC and $COMVAR.PROC to account for the change of machine type from a z15 to a z16. In fact, all of this was able to be done ahead of time. Not even the serial number needed to be changed, as that was virtualized. At a later date, LRS is scheduled to remove the z15 from those members.
Minimum Effort, Maximum Results
In the end, the customer was very pleased with the speed and ease of the hardware migration. The success of this project came down to three main elements. Firstly, we started with a well-developed and documented plan. Second, we spent ample time preparing the operating systems for the change of processors. Finally, due to the compactness of the system and need to install in a fairly tight physical space, it was important to minimize the burden on the customer’s technical staff in preparing the area for the system upgrade.
The moral of the story? In the world of IBM Z, even changes that sound intimidating — like changing out one production mainframe for a newer one — can be easier than most people imagine… assuming you have an experienced partner.
Next time you are facing a daunting challenge like this, we invite you to ask how LRS can assist with your IBM Z hardware upgrade, regardless of your hardware vendor. The project that seems like such a challenge may be easier than you think.