OpenStack Operations Guide

Chapter 4. Compute Nodes

In this chapter, we discuss some of the choices you need to consider when building out your compute nodes. Compute nodes form the resource core of the OpenStack Compute cloud, providing the processing, memory, network and storage resources to run instances.

Choosing a CPU

The type of CPU in your compute node is a very important choice. First, ensure that the CPU supports virtualization by way of VT-x for Intel chips and AMD-v for AMD chips.

Tip

Consult the vendor documentation to check for virtualization support. For Intel, read “Does my processor support Intel® Virtualization Technology?”. For AMD, read AMD Virtualization. Note that your CPU may support virtualization but it may be disabled. Consult your BIOS documentation for how to enable CPU features.

The number of cores that the CPU has also affects the decision. It’s common for current CPUs to have up to 12 cores. Additionally, if an Intel CPU supports hyperthreading, those 12 cores are doubled to 24 cores. If you purchase a server that supports multiple CPUs, the number of cores is further multiplied.

Multithread Considerations

Hyper-Threading is Intel’s proprietary simultaneous multithreading implementation used to improve parallelization on their CPUs. You might consider enabling Hyper-Threading to improve the performance of multithreaded applications.

Whether you should enable Hyper-Threading on your CPUs depends upon your use case. For example, disabling Hyper-Threading can be beneficial in intense ...