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VMware CTO Cites Virtues Of Virtual Machines

Feb 27, 2009 (06:02 AM EST)

Read the Original Article at http://www.informationweek.com/news/showArticle.jhtml?articleID=215400005


In contrast to relatively wan first-generation virtual machines, virtual servers can be workhorses, suitable for intense data center operations in all but the most extreme environments.

VMware CTO Stephen Herrod said virtual machines can safely support much larger workloads than previously assumed, and many thousands of virtual machines will one day be managed through a single management console.

He used those examples in a keynote at VMworld Europe to explain what the virtual data center operating system is all about. In the early days, x86 instruction set virtualization was used to run one workstation application at a time, fooling the resident operating system into believing it was one of its own applications.

But such modest beginnings led to an assumption that virtual machines tend to be slender, thinly provisioned shadows of a real server and couldn't be used to run complex transactions or applications requiring high data throughput. Those notions should be shelved, Herrod said in his speech.

First-generation virtual machines on servers tended to be configured to use one or two virtual CPUs (an assigned share of the server's real CPUs), 4 Gb of memory, and 300 Kbps of network bandwidth.

Those resources were sufficient for many early virtual machine tasks, Herrod said. But as companies rely more heavily on virtualization, they're equipping virtual machines with four virtual CPUs, 64 Gb of memory, and 9 Gbps of bandwidth.

As server cores increase to six and eight per CPU, it will soon be routine to build virtual machines for large workloads that rely on eight virtual CPUs, 256 Gb, of memory and 40 Gbps of bandwidth. Such virtual machines will be able to produce 200,000 I/O operations per second and keep up with database workloads in all but the most extreme environments, Herrod predicted.

An Oracle 11g database running on a virtual machine under Red Hat Enterprise Linux on a "next-generation," eight-way Xeon server will be able to do 24,000 transactions per second, based on its use of eight virtual CPUs, Herrod said in his talk. The specific chip architecture wasn't named during the speech.




As the database transaction activity picked up, Herrod said use of eight virtual CPUs showed "near prefect scaling." In other words, doubling the virtual CPUs doubled the database throughput.

"Oracle has done a very good job of scaling" its database server to take advantage of additional CPUs, he added. Not all server systems are engineered to take advantage of multiple CPUs. It took transactions being drawn off of 510 disk spindles simultaneously "to saturate what this single virtual machine could drive," Herrod said.

"There's no excuse not to run your database system in a virtual machine," Herrod said.

In another example, he said a Web server running on a virtual machine on a four-way, 16-core piece of hardware, such as the HP ProLiant 585 G5, can produce a SpecWeb2005 benchmark of 44,000, or the equivalent of 3 billion views per day. The SpecWeb2005 result stands as a record for 16-core machines, he said. For purposes of comparison, he said eBay generates about 1 billion views a day, he said.

VMware has virtual data center operating features coming in the form of a vShield product late this year. They will implement security zones across physical servers, with the protections of a given zone following an application around if it's moved from one physical server to another, Herrod said. Its vSafe API allows third parties such as Symantec and McAfee to work on virtualization security products as well, he said.

VMware is also expanding the capacity of its former Virtual Center software to manage multiple virtual machines. Now called vCenter Server, the management interface can manage 2,000 VMs on up to 200 physical servers. In the future, it will manage 3,000 VMs on up to 300 servers. VMware is working on LinkMode for vCenter Server, which will let one management interface track 10 vCenter Servers simultaneously or 30,000 virtual machines.

The virtual data center operating system has great potential to concentrate more operations into the hands of fewer systems managers, Herrod said. It can incorporate more automated operations governed by rules and policies, such as provisioning servers, and saving energy by shifting virtual machines around, he added.


As IT groups spawn new virtual machines at a breakneck pace, security is too often an afterthought. Can VMware's dominance of the enterprise server virtualization market buy us some breathing room? InformationWeek has published an independent analysis of this topic. Download the report here (registration required).