1. A method of administering a plurality of virtual machines (‘VMs’) in a distributed computing environment, the distributed computing environment comprising a plurality of hosts, one or more of the hosts executing a virtual machine monitor (‘VMM’), each VMM supporting execution of one or more VMs, the method comprising: assigning, by a VMM manager, the VMMs of the distributed computing environment to a logical tree topology, including assigning one of the VMMs as a root VMM of the tree topology; and executing, amongst the VMMs of the tree topology, a broadcast operation, including: pausing, by the root VMM, execution of one or more VMs supported by the root VMM; sending, by the root VMM, to other VMMs in the tree topology, a message indicating a pending transfer of the paused VMs; and transferring the paused VMs from the root VMM to the other VMMs.