In-Depth

An Operating System Reloaded: IBM Preps Major z/VSE Overhaul

Next version of z/VSE looks like an operating system reborn

• By Stephen Swoyer
• 10/30/2007

IBM Corp.’s z/VSE operating environment is still going strong. Although z/VSE doesn’t boast much in the way of market share or revenue growth—not, at least, when compared to other, sexier System z workloads, such as Linux or zSeries Integrated Information Processor—Big Blue continues to invest in and improve the z/VSE experience.

If ongoing technology investment and new operating system revisions are positive indications of a platform’s viability, z/VSE looks as viable as ever.

Consider IBM’s upcoming z/VSE 4.2 release, for example. While Big Blue has been slow to introduce support for Linux and other next-gen workloads in previous iterations of z/VSE—at least relative to what it’s done with both z/VM and z/OS—the latest version of that venerable operating environment looks like VSE reborn, with better support for z/Linux, a new Encryption Facility, expanded storage support, and improved performance and scalability.

The rub, of course, is that customers will have to wait until late next year to get their hands on it: z/VSE 4.2 isn’t slated to ship until Q4 of 2008.

By the time it does ship, it could help fuel pent-up demand.

The impetus, IBM officials say, is the ever-increasing uptake of Big Iron Linux: as customers deploy more zLinux workloads on System z mainframes, they’re increasingly running them in conjunction with z/VSE applications.

For one thing, says Jerry Johnston, System z technical sales specialist and Boeblingen Lab senior advisor with IBM, the new release should make it easier for customers to expose their VSE applications to zLinux.

"There are a number of integration possibilities," he says. "Each customer is different. For example, four European customers presented solutions at the recent [Guide Share Europe] conference in Boeblingen. A couple of them have z/VSE applications that access data stored in DB2 UDB on Linux on System z. Another is working on WebSphere applications under Linux on System z that can access data stored in files on z/VSE."

There’s also HiperSockets, z/VM, and Integrated Facility for Linux (IFL) integration, too. "Customers can implement integrated solutions that exploit System z 'HiperSockets' for fast, secure communications between z/VSE and Linux on System z," he continues. "They can take advantage of low-cost IBM System z Integrated Facility for Linux (IFL) specialty engines. Last, but not least, customers can take advantage of IBM's world-class virtualization technology, z/VM, to get the most from their Linux on System z and z/VSE systems."

Removing Limits

z/VSE 4.2 also eliminates a long-standing VSE bottleneck: a limit of 255 concurrent processes. In most cases, Johnston says, users have been able to work around this; once z/VSE 4.2 becomes generally available, they won’t have to. "The z/VSE operating system itself uses 32 of those [tasks]. Subsystems like CICS, VTAM, TCP/IP, DB2, [and so on] each use a number of tasks. They reduce the number of tasks available to the user for application programs," he explains. "z/VSE V4.2 users will have more than 255 tasks to work with. That means, for example, they can create more CICS and batch partitions in z/VSE V4.2. More partitions increase the ability of the system to do useful work, [which leads to] better scalability."

The new revision will also explode a traditional storage bottleneck, Johnston continues. True, z/VSE 4.1—which shipped earlier this year—eliminated the long-standing 2 GB central storage restriction (it boasted support for up to 8 GB of real storage), but z/VSE 4.2 will go that several orders of magnitude better.

"Now, z/VSE V4.2 is designed to support up to 32 GB … of real processor storage," he says, which could entail additional scalability benefits. "Larger real memory may lead to a reduction in paging. Paging occurs when a task needs central storage but no free storage is available. At that point, the operating system has to find a page to remove, transfer it to external page storage, and start the new activity. From a system point of view, paging is just wasted activity and to be avoided. z/VSE V4.2's support for up to 32 GB of real storage means that, in many cases, less paging will occur."

Improved Security

Finally, Johnston concludes, z/VSE 4.2 will ship with a new Encryption Facility to better secure business data. This is a more involved proposition than it might seem, he points out. For starters, the function of the new Encryption Facility for z/VSE V1.1 is roughly equivalent to that of the z/OS variant (also at version 1.1). This means both implementations are also interoperable. "Tapes created by one can be read by the other," Johnston says.

At all events, z/VSE’s new Encryption Facility will help protect against the accidental (and frequently quite literal) loss of data.

"You may have seen news stories about tapes that have been 'lost.' There have been articles about tapes that have been misplaced, stolen, dropped off the back of a delivery truck, taken from a truck while the driver was having coffee, etc.," he explains. "One solution to avoid the compromise of business/personal data is to encrypt the tape. … If a tape falls into the wrong hands, the information is safe because it cannot be read without knowing the key."

VSE’s new Encryption Facility will be packaged and licensed as an optional, priced feature of IBM’s VSE Central Functions version 8, according to Johnston. This product includes the basic VSE operating system, along with a passel of other features. As with z/OS, the Encryption Facility for z/VSE also exploits built-in System z features to accelerate encryption and reduce processing costs. "[Encryption Facility] for z/VSE exploits new System z hardware instructions designed to accelerate the encryption process. These instructions are part of a no-charge, optional hardware feature—available on z990/890, z9 EC, and z9 BC models—known as CP Assist for Cryptographic Function," Johnston indicates. "Similarly, when compressing data, [Encryption Facility] for z/VSE uses System z hardware compression instructions."

As an added bonus, it’ll also be eligible for the Midrange Workload License Charges pricing scheme that Big Blue introduced earlier this year.