An effective virtualization project will need significant investment if, as Michael Crader of BT says, you are going to avoid building “tomorrow's legacy systems today”. That means building a business case and implementation plan that will work for the specific workloads, current infrastructure, and organization. A good virtualization project entails a complete overhaul of the physical architecture, including servers, storage, and storage network. Even more important is a logical overhaul of the allocation, backup, recovery, compliance, archiving, and charge-back software and processes.
BT initiated a pilot for a specific workload (test and development). The team tested and revised the physical and logical architectures specifically for the type of workload in question (i.e., infrastructure computing). This allowed them to demonstrate to the CFO that significant investment was justified. The team extended that architecture to specific infrastructure applications based on Intel X86 architecture. Key BT storage decisions were using FC to avoid I/O bottlenecks, using storage controllers that allowed intermixing of all storage types, using very large numbers of virtual snaps for backups, using disk-to-disk backup, and using thin provisioning to over-allocate storage(almost 2:1).
The type of architecture developed and applicability of virtualization will vary by workload type. Michael Crader’s team identified the characteristics of X86-based applications that were not suitable and did not virtualize them. The architecture and products used for BT’s larger UNIX systems is very different.
Action Item: IT executives should ensure that virtualization projects include a complete re-architecture of the physical and logical infrastructure. Virtualization should include storage and servers. To be effective, significant new investment is required, and IT should demonstrate that the new architecture works for real in a pilot. Most important of all, the workload type, not products or fashion, should determine the architecture.
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