In-Depth

Big Blue: Still Pushing the Envelope

IBM virtual tools range from desktops to servers -- with a mainframe twist on the side.

• By Doug Barney
• 06/01/2008

The answer? The IBM System/360 Model 67 mainframe, a machine that ran applications in virtual machines (VMs) and, in fact, virtualized all the hardware interfaces as well. That machine, and the first VM hypervisor, came out in 1968.

The Model 67 may have gone the way of the dodo, but virtualization is still very much in IBM's crosshairs. Today IBM has a dizzying array of virtual tools, including management tools, virtual I/O products, hypervisors for all its major server lines, and storage virtualization wares.

For IBM, virtualization means more than simplifying the data center; it's also part of the company's "green computing" mission and its overall data center rationalization strategy. "Virtualization for IBM is the cornerstone of our strategy -- it is a centerpiece for what we do and it is not just a systems thought. It is an important part of our strategy across our software and services businesses as well," says Becky Austin, director of IBM's virtualization strategy.

Global Services
When it comes to virtualization, IBM isn't just about pushing boxes and software. IBM, especially through its Global Services, works with large companies to devise overall strategies to migrate legacy server infrastructures to IBM offerings. The idea is to not just replace older servers with faster, newer ones, but to take a holistic view of what IT wants to achieve.

When that's done, the next step is to build an architecture that, largely through virtualization, reduces data center square footage, saves money on power and cooling, increases availability and improves flexibility. "We are starting to move beyond just the problem you need to solve this quarter and how much hardware capacity we can sell you. [We are asking,] 'Where do you want to take your business in the next three- to five-year period and what will it take for you to get there?' What comes into play here is more of a services and consulting engagement," explains Austin.

Once it analyzes the needs, IBM can steer IT toward the server line that makes most sense, including:

• System x. These are x86-based rackmount servers.
• BladeCenter servers. These are also based on the x86 architecture.
• System p. These are high-end, Power-based servers that run Unix and Linux.
• System i. This Power-based line uses PowerVM. System i are mid-range servers that replace the AS/400 and the older System/36 and System/38. System i also supports VMware.
• System z. What we've known for years as mainframes, which may now be the ultimate VMs

Different Strokes
IBM has different approaches, depending on the server line. "What sets us apart is the breadth and depth of the capabilities. There's a tendency to associate [virtualization] primarily with x86-based servers and Windows and VMware, which are important to IBM but only a small piece of the picture; a small slice of the market," says Austin. "We have such a range of server virtualization technologies because we have a broad range of customer requirements. [For example,] at the enterprise level, when you have users with very large-scale, complex problems and they're looking for centralized administration and extraordinary levels of scalability, reliability and security, they go for the mainframe."

For industry-standard servers-the System x and BladeCenter-IBM largely touts third-party hypervisors from VMware Inc., Microsoft and Citrix Systems Inc. (XenServer). These two lines also support hardware-assist virtualization from Intel Corp. and Advanced Micro Devices Inc.

"If you look at our x86 or modular platforms, our tendency is to support industry-standard hardware components and software. So we use Intel and AMD chips, memory and controllers and devices and other things. Our software stacks tend to be standard Microsoft or Linux distributions and off-the-shelf, third-party apps that do not require modifications. We add value in terms of systems management capabilities and higher degrees of availability and reliability or improved energy efficiency," explains Austin.

For BladeCenter I/O virtualization, IBM teams with Cisco and offers the Cisco VFrame solution that lets servers share networking fabrics.

Wolf on IBM

IBM's track record includes decades of experience and innovation in virtualization. Many of the challenges faced by x86 virtualization today are reminiscent of improvements made to IBM mainframes in decades past. Of course, the difference today is that virtualization has grown immensely on commodity hardware. IBM's greatest weakness, in my opinion, is not in its technology but in its policies. While the industry is moving away from licensing software based on physical hardware resources, IBM is pushing forward with further ingraining software licensing terms to hardware, as evidenced by their Processor Value Unit (PVU) licensing model. Hardware-centric licensing is fine when virtualization is achieved by hardware partitioning such as with IBM LPars, but is extremely difficult to manage when software (namely a hypervisor) is used to virtualize hardware resources. When underlying physical hardware is abstracted and virtualized, it's very difficult to track licensing compliance when physical hardware isn't visible from within a virtual machine's guest OS. IBM would be viewed more favorably by prospective clients if they offered a licensing model favorable to x86 virtualization, such as by offering the option to license their software by virtual CPU, virtual machine instance, or by the number of connected users or user seats. -- Chris Wolf

Meanwhile, the IBM BladeCenter Open Fabric Manager virtualizes Fibre Channel and Ethernet connections. This tool not only turns these adapters into shared devices, but quickens the setup and redeployment of servers, VMs, storage and networks. It does all this by virtualizing hardware addresses, decoupling them from hardware devices and adapters. New addresses can be assigned to old devices, or new devices can inherit the addresses of older ones, making hardware installation that much faster.

For proprietary systems such as System z mainframes and the Power processor-based System p, IBM has homegrown virtualization tools.

"As you move onto our mainframe and Power platforms, our differentiation typically comes through more IBM value- added technologies and capabilities. We still support open standards on those platforms and on AIX," explains Austin. "At the same time, we've used our proprietary hypervisors and our systems management capabilities to set that platform apart-that is common in the Unix spaces-Sun has differentiated their stack in some of the same areas. And as you move into the mainframe, it's even more of an IBM- rich stack as opposed to industry standard components."

Despite these efforts, analyst Judith Hurwitz of Hurwitz and Associates says Big Blue still has work to do.

"I would say that IBM is playing catch up a bit. But it's also an area that they're putting a lot of firepower behind and it's going to emerge as a major strategic approach for them. The company is also going to wrap cloud computing as a technique for virtualization into the mix."

The System p Approach
The Power processor, formerly called the PowerPC, lost a little luster after Apple Inc. switched from it to dual and multi-core Intel chips. IBM, however, is still firmly behind the processor, which not only drives Big Blue's record-breaking supercomputers, but the System p server line as well.

Aimed at high-capacity environments, System p usually runs Unix (AIX) or Linux. Efficiency and performance are key System p selling points, and here virtualization plays a crucial role.

So let's take a look at how IBM virtualizes System p environments. On the hypervisor side, System p supports IBM's own PowerVM (actually a family of virtualization technologies) as well as eServer. Power VM uses paravirtualization, which means the OSes are tweaked to work with the hypervisor.

For System p storage, IBM offers the SAN Volume Controller, which pools heterogeneous storage. System p can also virtualize I/O, letting System p servers and the OSes themselves share storage and network adapters.

On the management side, IBM offers the IBM Virtualization Manager, a tool that handles both virtual and physical servers.

There are a couple of other System p virtualization goodies, including: