VIRTUAL MACHINE IMAGE WRITE LEASING

A system that includes multiple hosts, each having physical resources, a hypervisor, and a host agent that causes the virtual machines to operate above the hypervisor so as to be abstracted from the physical resources. A host fabric reviews requests to instantiate or upgrade a virtual machine, identifies a corresponding virtual machine image to instantiate the virtual machine from in order to honor the request, and determines whether the virtual machine to be instantiated has a valid lease on the virtual machine image. If the requestor does not have a valid lease, the request is blocked. If the requestor does have a valid lease, the host fabric facilitates the instantiation of the virtual machine from the virtual machine image. This prevents or eliminates the chances of multiple instances of the same virtual machine image writing to the virtual machine image at the same time.