Jacques Greyling, vice president of data center infrastructure for outsourcing provider Rackspace, says cloud is typically best for dynamic workloads that have demand spikes because servers can be spun up and down quickly. Static and sensitive workloads are more likely to run on infrastructure dedicated to individual customers in a managed hosting environment, he says. There are exceptions to any rule; Netflix proudly runs most of its business-critical video streaming services on Amazon Web Service's cloud, for example, as do many web startup companies who live all in AWS's cloud.
The technology to support the nirvana vision of hybrid cloud connectivity that allows dynamic scaling is still a slight ways off, Greyling says. It requires significant changes in network topology, which the company is addressing by implementing software defined networking functionality. Doing so allows the easy creation of virtual LANs for individual customers and segmenting them off from one another. Combine that with common management platforms -- in Rackspace's case OpenStack - that spans the customer's site and the Rackspace cloud, and the hybrid cloud model starts to become a reality.
There is hope
Despite all the challenges - from virtualization management, to converged infrastructure to the cloud - companies are making progress toward the virtual data center. Take Michael Ferguson, director of IT for mid-sized Miami law firm Rennert, Vogel, Mandler & Rodriguez, who two years ago made a switch to embrace compute and storage virtualization.
It's not necessarily the perfect nirvana vision, but it has significantly eased IT management. He now centrally controls all of the servers from a single screen using VMware vCenter, and his virtualized storage array powered by storage hypervisor platform DataCore's SANSymphony has created a highly-available environment, backed up with off-site collocation disaster recovery.
"After two years, I've already paid off all of my investments, plus more," says Ferguson, who hasn't bought a new server since installing the system, even though the firm has continued to grow.
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