Private Clouds: Tough To Build With Today's Tech

Let's not spend time debating whether fully virtualized data centers will become the norm. They will, and sooner than you may think. You have bigger challenges than how soon you can get 50% or 75% or 99% of your servers virtualized.

Almost half of companies buy into the broader vision of a private cloud, finds our InformationWeek 2011 Virtualization Management Survey of 396 business technology pros. By private cloud, we mean an internal network that combines compute, storage, and other data center resources with high virtualization, hardware integration, automation, monitoring, and orchestration. But getting there with today's technology will be tough. We'll look at the range of problems IT faces, such as multivendor environments, limited automation, and still-emerging technology and standards.

Standards are scarce indeed, making every purchasing decision dicey. You must understand how every component interacts with every other component, but since extensive server virtualization has increased operational complexity, this can be an extraordinarily difficult thing to get your arms around. IT teams looking to conventional network and systems management products for help are finding that these expensive tools are inadequate to the task at hand.

"The only savings realized from virtualization is fewer physical servers," says one respondent to our survey. "Costs have increased via more expensive servers with bigger I/O and more memory, added cost of the hypervisor, and a much more difficult time to resolve problems when they occur."

VMware is still the go-to vendor when IT organizations talk enterprise-class server virtualization.Only 36% of the respondents to our survey have secondary hypervisors in use at their companies. But Citrix and Microsoft are closing the gap.

Asked to rate the importance of a dozen virtualization features, survey respondents cited high availability as No. 1 and price a very close second. Both Microsoft Hyper-V R2 and Citrix XenServer offer high-availability features with a reasonable price tag. VMware also offers high availability in its entry-level packages, except that it doesn't bundle features like Distributed Resource Scheduler, for machine load balancing, with its low-cost vSphere Essentials, making it an incomplete offering.

Other highly valued factors include live virtual machine migration (available from all major vendors), fault tolerance, load balancing, and virtual switching/networking. Citrix and Microsoft recently cozied up to Marathon Technologies to provide fault tolerance for their platforms.

The features VMware offers that the others don't--like Storage DRS, which load balances data store I/O, and Storage vMotion--land in last place in our survey. VMware's decision this year to increase its price beyond a certain virtual memory allocation was met with such howls from customers that VMware raised the limit--but that move only delays a price increase that could drive companies to consider alternatives. If it's bells and whistles like Storage DRS and Storage vMotion that VMware expects to justify higher licensing costs, our survey respondents aren't buying it. "With steady improvements to Hyper-V and Xen, and Oracle's integration of Virtual Iron into their VM product, we have lots of alternatives to consider," says one respondent.

However, mixing production hypervisors almost guarantees that companies won't have a unified, automated disaster recovery scheme. And it can require some deep expertise if you want one policy to govern all of your systems, a common goal.

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