1. A computer-implemented method, comprising: identifying, by a host controller computing device, a virtual machine (VM) image of a new VM to be placed by the host controller computing device on one of a plurality of candidate host machines; for each candidate host machine of the plurality of candidate host machines, identifying, by the host controller computing device, a VM image for each VM hosted by the candidate host machine; and determining, by the host controller computing device, the candidate host with the most VMs having identical VM images to the new VM.