Performance evaluation and capacity planning for a scalable and highly available virtualisation infrastructure for the LHCb experiment

The virtual computing is often run to satisfy different needs: reduce costs, reduce resources, simplify maintenance and the last but not the least adds flexibility. The use of Virtualization in a complex system such as a farm of PCs that control the hardware of an experiment (PLC, power supplies, gas, magnets...) put us in a condition where not only an High Performance requirements need to be carefully considered but also a deep analysis of strategies to achieve a certain level of High Availability. We conducted a performance evaluation on different and comparable storage/network/virtualization platforms. The performance is measured using a series of independent benchmarks, testing the speed and the stability of multiple VMs running heavy-load operations on the I/O of virtualized storage and the virtualized network. The result from the benchmark tests allowed us to study and evaluate how the different VMs workloads interact with the Hardware/Software resource layers.