I'd like to demonstrate some of OpenStacks HA/FT features (most importantly live migration and storage replication). For that purpose, I have a machine with 32 GB RAM and a Xeon e3v2 with 4 cores (8 threads). So far, I've managed to get MAAS and Juju up and running, but I'm not sure about the number of virtual nodes I can safely deploy (and the CPU / RAM overcommit ratio, although I've read somewhere that the physical CPU can handle overcommitting with 1-vcpu-machines pretty well).
Currently, the VM that runs MAAS uses 1 vCPU and 8 GB RAM, Juju runs on the host. That leaves me with 7 vCPUs and 24 GB RAM without overcommitting any resources. What I've come up with is the following:
1 Controller Node: 2vCPUs, 4GB RAM - RabbitMQ, mysql, keystone, dashboard, cinder, nova-cloud-controller and glance in lxc containers
2 Ceph nodes: 1 vCPU, 4GB RAM each - ceph
2 Compute nodes: 2 vCPUs, 8GB RAM each - nova-compute
1 Network node: 1 vCPU, 2GB RAM - quantum-gateway
Plus the MAAS host: 1 vCPU, 8GB RAM
This would result in a total of 38 GB RAM and 10 vCPUs, so I'm overcommitting a little.
My actual question is if anyone has a better Architecture in mind. I really just plan to show some features of OpenStack (or Clouds in general).