Compute hardware considerations
It's certainly possible to deploy OpenStack on Power or Z series systems from IBM or Solaris systems from Oracle, but the vast majority of OpenStack deployments use Linux on 64-bit Intel systems. Selecting a hardware platform for compute infrastructure in OpenStack is similar to selecting a hardware platform for any other workload in the data center. Some organizations have a brand loyalty to a particular vendor based on reputation, past performance, or business arrangements and some organizations ask hardware vendors to bid on projects as they come up. A small number of organizations choose to assemble their own systems from components, but most OpenStack deployments use the same commodity systems that would be deployed to run any other Linux workload.
With that said, we've definitely seen hardware configurations that work well with OpenStack and ones which had to be reconfigured after the fact. We'll try to help you avoid that second purchase order in this...