Companies Push The Limits Of Virtualization
New software, hardware, and networking systems let IT managers stung by the recession go further with server consolidation.
When it comes to virtualizing servers, few companies can match Accenture's outsourcing arm. The unit hosts customers such as the airline reservation site Navitaire.com, as well as several high-volume trading and insurance systems. Accenture's service-level agreements with these customers impose thousands of dollars of penalties for each minute of downtime.
With money like that at stake, you'd think IT architect Eric Ulmer would be conservative when it comes to virtualizing his Minneapolis, London, Sydney, and Cologne data centers. Not so. While most other companies find their servers are maxed out at 10 or 12 virtual machines per server, he's designed ones that run 30 VMs each. And Ulmer's not stopping there. He'll move to 60 VMs per server as soon as he's completely confident that VMware's new vSphere 4 virtualization management software is up to the task.
More Storage Insights
- Building a Hybrid Cloud in Government: It's not that Complicated
- Maximize the benefits of virtualization for greater ROI
- Virtualizing Disaster Recovery Using Cloud Computing
- Creating an Actionable View of Data with Data Virtualization
Ulmer admits, though, that the big numbers make him nervous. "With virtualization, a lot of customers go down if one server fails," he says. "If five customers are down, we don't have enough phone lines to take all their complaints."
But it's not stopping him. His testing shows that VMware's ESX Server can run 60 virtual machines and possibly more. His group once assigned all the VMs intended for two servers to one by mistake. Ulmer was surprised to find the server humming along running 100 VMs without a noticeable performance hit.
Ulmer and his team are among an elite group of data center pioneers who right now are testing the limits of server virtualization, pushing for the next tier of performance even as most companies are just getting comfortable with the technology. They're increasing the number of VMs per server in order to save electricity, capital costs, and even labor when the right management tools are in place. In this deep recession, many IT managers would like to go further with server consolidation. It's these pioneers who are discovering the limits to how many virtual machines can practically be loaded onto any one server, and what problems to watch for as each additional VM stresses the overall system.
Ulmer and others who are pushing for more performance are getting plenty of encouragement from vendors, whose next generation of virtualization software and servers appear to be converging toward a big jump in productivity and capacity.
VMware has just launched an upgrade to its vSphere 4 data center operating system that shows how vendors are trying to push the state of the art in virtualization. With upgrades that'll be available this month and next, VMware claims companies can get a 30% productivity gain using existing servers--so for companies running 10 VMs today, 13 should be within reach, says Bogomil Balkansky, VP of product marketing.
Couple that with server makers that are launching their next-generation machines based on Intel's Nehalem, or Xeon 5500, chip, and you're talking major virtualization advances. The 5500 is really the first chip to escape from the personal computing bias of the original x86 chips. It has a memory controller built onto the chip instead of off-loaded to a separate dedicated chip, reducing latencies encountered as a VM's operating system manages the memory that its application is using. The 5500 also has more built-in virtualization support for the hypervisor. It's much more of a multithreaded server processor capable of juggling many assignments across its four cores, making it better equipped to run multiple VMs.
IBM and Hewlett-Packard each say they're seeing gains of just over 60% in benchmark tests of their new Xeon 5500 servers in virtualized environments, compared with previous generations. That means a hardware shift could let the typical 10 VM-per-server company bump up to 16. Taken together, the VMware software upgrade and the new server designs could very well let companies double the number of virtual machines they run per server.
We'll see if Cisco delivers on that claim in the real world. But if it can, going from 10 to 40 VMs per server would put more IT managers in Ulmer's world of extreme virtualization. It also would introduce more of them to the many problems he's dealing with.