News Stay informed about the latest enterprise technology news and product updates.

IBM's new mainframe z/OS to take on app availability

Upcoming IBM z/OS 1.12 addresses nagging application availability issues.

IBM's upcoming z/OS 1.12 mainframe operating system addresses a problem some mainframers have had for decades.

For some mainframe users, the major bonus is that the operating system, which is due out in September, addresses application availability. The z/OS 1.12 release offers a new control-area reclaim capability for VSAM key-sequenced data sets (KSDS).

More on IBM z/OS:
IBM z/OS 1.11 preview

IBM ends 31-bit z/OS mainframe support

Mainframe users share z/OS 1.10 stories

Every "z/OS installation will find different things they think are significant or that will be of benefit to their environment," said Mark Zelden, the senior software and systems architect for commercial insurance provider Zurich North America. For Zelden, this application availability fix is big. According to IBM, these key-sequenced data sets can become fragmented and create empty control areas that consume disk space. That, in turn, can increase the size of indexes and undermine performance. Currently, defragging these data sets may mean application outages, not good on a server platform known for little downtime. With the new z/OS capability, users can reclaim the empty control areas dynamically.

"This means you will no longer have to schedule application outages or close files to CICS just to reorg VSAM KSDS data sets," Zelden said.

The new version of z/OS will improve partition data sets extended (PDSE), which IBM has encouraged mainframe shops to use rather than traditional partition data sets (PDS) because they have more features and are considered more flexible. However, Zelden said many shops have been reluctant to embrace PDSE "since there have been many problems with their stability over the years since they were first introduced in MVS/ESA."

The improvements to PDSE include reducing processing delays that can occur when two systems access the PDSE simultaneously; new utilities and application programming interfaces to verify the state of a PDSE; and the ability to identify a corrupt PDSE before the system enters a wait state, making debugging easier.

IBM distinguished engineer Robert Rogers said another important feature of the new release is improvements to its Predictive Failure Analysis, which was first introduced in z/OS 1.11. PFA will now be able to monitor the rate of systems management facilities (SMF) record generation. If it's abnormally high, it sends a warning message that could potentially prevent an outage. It can also take into account normal activity spikes to prevent false alarms.

Another important new feature, in Rogers' view, is a capability called Run Time Diagnostics. The feature will help mainframers determine problems that are affecting the performance while the machine is live.

Big Blue typically releases new versions of z/OS, its major mainframe operating system, in the fall, and usually previews features sometime in the spring, or earlier. This year is no exception. In an announcement letter last week, IBM said that z/OS 1.12 "can proactively work for you to help promote improved operations, availability, manageability, and security through innovative self-learning, self-managing, and self-optimization capabilities."

Mark Fontecchio can be reached at

Dig Deeper on IBM system z and mainframe systems

Start the conversation

Send me notifications when other members comment.

Please create a username to comment.