In-Depth
IBM Bringing Windows to the Mainframe Later This Year
IT mainframe pros will have to wait until Q4 to get their first look at IBM's Windows-on-zBX offering. Will it be worth the wait?
Last month, IBM Corp. took a first, crucial step toward supporting Windows on its System z mainframe systems. The company didn't formally announce plans to support Windows in z/VM, not did it offer a sneak peak or proof of concept for its zBX offering for Windows.
What it did do was make an important addition to the road map that it published when it first announced zEnterprise last July. This road map provides an outline for the delivery of hybrid zEnterprise BladeCenter Extension (zBX) offerings for System z. At launch, the IBM road map described several upcoming zBX deliverables, including IBM's Smart Analytics Optimizer and DataPower XI50z. It did not include a Windows-oriented zBX deliverable.
It does now. By Q4 of this year, IBM said in a statement that it plans to deliver "select IBM System x blades running Microsoft Windows in the IBM zEnterprise BladeCenter Extension Model 002."
At this point, IBM plans to support Windows running in the context of its zBX sidecar -- not Windows (ala Linux) running in the context of z/VM on zEnterprise itself. Big Blue says Windows-based zBX blades will be managed via its Unified Resource Manager (URM), which permits data centers to manage aspects of their mainframe and BladeCenter platforms as a single virtualized system.
Long Time Coming
Big Blue's Windows-on-zBX announcement has been long anticipated. Since IBM first introduced zBX, industry watchers have argued that the company should consider extending the technology to Windows -- so the prospect of Windows-on-zBX has been treated as a distinct possibility.
Now that it's official, the implications of Big Blue's decision seem nothing short of staggering. "With the System x blades running Windows as well as Linux[,] IBM indeed can make a strong case for IT recentralization on the zEnterprise, especially for multi-tier, multi-platform enterprises," wrote Alan Radding, a veteran of the mainframe, minicomputer, and high-end server segments who blogs about mainframes at DancingDinosaur.
"This case will be based on the zEnterprise's centralized management efficiency, the potential for greater optimization, and the resulting performance improvements. It's a good story that could catch on if IBM keeps the pricing competitive."
The rub, of course, is that Big Blue isn't talking -- at all -- about pricing.
This isn't such a bad strategy, inasmuch as it effectively "freezes" the market, Radding argued. "Multi-platform, multi-tier enterprises considering an upgrade of their Windows servers to the latest offerings from HP or Oracle [Sun] or others now know this option is coming in the fourth quarter and may wait until they see the pricing, licensing, and performance details," he wrote.
It also begs the question as to which kinds of workloads shops would shift to Windows-on-zBX. After all, wrote Radding, just because you can host Windows workloads in a zBX context doesn't necessarily mean you should.
A lot, he reiterates, will depend on pricing.
"Microsoft Exchange and Microsoft SharePoint, probably [Microsoft's] two most popular enterprise server applications, are good bets to stay where they are and not move to the z," Radding pointed out. "Similarly, the Microsoft Office Suite will stay where it is unless someone wants to attempt to virtualize a slew of Office desktops on a handful of zBX IBM x blades as a [virtual desktop infrastructure] play. Without knowing the performance and pricing details of the zBX System x blades, it is impossible to intelligently make such decisions."
A Compelling, Albeit Incomplete, Vision?
Like Radding, Wayne Kernochan, a principal with Infostructure Associates, sees Windows-on-zBX as a milestone deliverable.
Putting aside the (all-important) pricing angle, Kernochan thinks other aspects of Big Blue's Windows-on-zBX road map are fuzzy or incomplete, too.
"Full support of application-level administration and load balancing for Windows platforms is not yet in the IBM road map," he observes, "and as for full integration of Windows platforms with the mainframe in a private cloud, that's at the very least not yet in the road map, and perhaps a goal that may never be reached."
Elsewhere, he points out, some of the most intriguing Windows-on-zBX use-cases still won't be practicable by the time Big Blue ships its first Windows-ready zBX blades later this year. A lot, after all, depends on support from ISVs.
"IBM's promised Windows support on zBX, on the face of it, takes us only a little way down the path to the full Windows-z integration," Kernochan writes. "It applies only on a 'hybrid' architecture ... that is new and not yet widely used. The tools to treat a Windows virtual machine as just another system for purposes of backup/recovery, monitoring, load balancing, and distributed-application creation within zBX won't be ready from third parties [at launch]."
Granting all of this, Kernochan says, Windows-on-zBX still promises to be a game-changer. For example, even if (as Radding suggests) hosting Exchange Server itself in a zBX context doesn't make a lot of sense, hosting Exchange message stores on zBX could prove to be an attractive option -- especially when paired with Big Blue's existing Smart Analytics zBX product. "Since Windows apps are predominantly scale-out, that means ... putting them on VMs on a zBX. Thus, e-mail storage plus analytics involving text is an obvious workload candidate, as is Web-site access to business-critical mainframe applications."
Putting aside the as-yet-unknown cost of zBX itself, Kernochan says that shifting existing Windows workloads onto zBX is an "extraordinarily low-risk" proposition.
"Mainframe consolidation has already demonstrated low risk, low cost, fast migration of Linux apps, and here, app recompilation isn't even needed in many cases," he writes. "IBM has been managing Windows apps under the same general infrastructure framework as Linux ones for a while, and has been integrating its management tools across all platforms for more than a decade."
He anticipates other benefits as well.
"[O]nce the apps are moved, they begin to take advantage of the mainframe robustness and security technology that has been baked into URM, and has begun to be baked into IBM's Integrated Service Management."