Todd Muirhead, performance staff engineer at VMware posted an article about Oracle Real Application Cluster (RAC) performance running on VMware vShere 4.1 over on the VMware VROOM! performance blog. Oracle RAC are used to run critical databases with stringent performance requirements.
In order to test the performance, three servers were used, two in a dual boot configuration between Red Hat Enterprise Linux (RHEL) 5.5 and and vSphere ESXi 4.1 and one running ESXi only to host the virtual machines when the two other physical servers were booted into RHEL so that the two VMs could preserved. Also the CPU configuration of the physical machines was limited in order to enable a direct performance comparison, because of the eight vCPU limitation of ESXi.
For testing the open source DVD Store version 2.1. was used, part of the VMmark 2.0 performance testing suite, released earlier this month. DVD store is a online transaction processing (OLTP) database workload which simulates customers logging on, browsing and purchasing DVDs from an online store. It includes database build scripts, load files and drivers programs.
"…In both the OPM and RT measurements, the virtual RAC performance was within 11 to 13 percent of the physical RAC performance. In an intensive test running on Oracle RAC, the CPU, disk, and network were heavily utilized, but virtual performance was close to native performance. This result removes a barrier from considering virtualizing one of the more performance-intensive tier-one applications in the datacenter…"