1. A method implemented in a virtual machine system for protecting against failure of hardware elements (HEs), the HEs to host virtual machine monitors (VMMs), virtual machines (VMs) and operating system (OSes), each of the VMMs to manage one or more of the VMs, and each of the VMs to run one of the OSes, the method comprising the steps of: booting, based on an information model of the virtual machine system, one of the VMMs on each of the HEs, one or more of the VMs, and one of the OSes on each of the VM, wherein the information model includes a graph of objects representing configured relationships between the HEs, VMMs, VMs, and OSes through parent child relationships between the graph's objects, wherein a distinguished name (DN) is stored in each of the graph's objects and those of the objects that are children of another object in the graph include the DN of their parent object thereby identifying the parent child relationships of the graph's objects, wherein the graph of objects includes: a domain object that represents the virtual machine system, HE objects that represent the HEs and that are children of the domain object, VMM objects that each represent one of the VMMs and that each are a child of one of the HE objects, VM objects that each represent one of the VMs, wherein a set of one or more of the VM objects is of a migration-enabled type and represents those of the VMs that may migrate between the VMMs, and wherein the VM objects of the migration-enabled type are children of the domain object and not of the VMM objects such that their DNs do not change with migrations between the VMMs, and OS objects that each represent one of the OSes and that each are a child of one of the VM objects or of the domain object, wherein the step of booting includes the steps of determining, for each of the VMs represented by the set of VM objects, a current management relationship that indicates which of the VMMs is to currently manage that VM; and updating each of the set of VM objects to reflect the determined current management relationship as a runtime association; and identifying, based on the runtime associations, which of the set of the VMs are hosted by a same HE of the HEs and are therefore vulnerable to hardware failure of the same HE; and receiving a trigger to migrate a first of the VMs from a first of the HEs to a different one of the HEs, the first VM represented by a first of the set of VM objects that is of the migration-enabled type.