In-Depth

How IBM Became the First Server Company to Support VMware

It all started when original founder Mendel Rosenblum spoke with Sequent Computer Systems about his ideas.

• By Tom Fenton
• 06/27/2018

At VMware's 20th anniversary event, Pat Gelsinger, the current CEO of VMware, invited some of the company's original founders to the stage for some Q&A. Someone from the audience asked Mendel Rosenblum about the origins of VMware, and Mendel stated that it all started when he spoke with Sequent Computer Systems about his ideas. This caught my attention because I used to work for Sequent Computer Systems and I had never heard about a connection between VMware and Sequent. Intrigued, I decided to look into the story a little deeper, and I ended up learning how IBM became the first server company to support VMware.

For those unfamiliar, Sequent Computer Systems (1983-1999) designed and built high-performance symmetric multiprocessing (SMP) that used NUMA architecture on Intel processors, which were mainly used to run large databases. Sequent was a great company to work for.

I reached out to Mendel to ask him for more information about his visit to Sequent. He kindly responded and told me that he was working on scalable OSes for large multiprocessors and he went up to Beaverton, Ore., and gave a talk at Sequent on his ideas. Although the technical folks at Sequent liked the approach, they doubted they had the engineering resources to implement it. Moreover, they pointed out that they needed their servers to run Windows NT, and they were unlikely to be able to get Microsoft to adopt the approach Mendel was proposing. Based on this feedback, Mendel started thinking about virtualization as a solution.

Now let's skip ahead a few years to 1999 when IBM bought Sequent. The remains of Sequent were very helpful to VMware when it came out with ESX. IBM took Sequent and started to build really big x86 machines, but found that the market for these systems was somewhat limited. You have to realize that back in that day Linux was still in its infancy and didn't scale that well. Furthermore, Windows NT was the Windows server of choice, but blue screens were a fact of life and no one was going to run their entire datacenter on a single instance of an OS; the best practice was to have one application running on a single server running a single OS.

The folks at IBM figured that if they ran VMware on these big servers, they could have multiple, isolated instances of OSes running on these big boxes and it would greatly increase the market for these servers. This caused them to partner with VMware and offer server consolidation, which ended up working well for both sides. By the way, what was considered a really big server in 1998, such as Sequent's NUMA-Q, had eight 200 MHz Pentium Pro processors, 0.5GB of RAM, and a 65GB hard-disk-drive subsystem. Pricing for an eight-way NUMA-Q system started at $675,000 (for about the same processing power and storage capacity as a low-end laptop today).

When I spoke with Eric Horschman (a longtime VMware product marketing employee) about this backstory, he said that it explains why IBM was the first server vendor to support VMware. The other server vendors were scared away by concerns about server consolidation cutting into their sales. Eventually other companies, such as HP, Compaq and Dell, among others, figured out that virtualization helped them sell their high-end boxes that were profitable, so they could get away from selling low-margin pizza boxes that were popular at the time.

And that is the story of how and why IBM became the first server company to support VMware.