1. A method comprising: initiating a power-on procedure for a virtual machine, wherein the virtual machine comprises a virtual memory space configured to be backed by a combination of swap space and machine memory; creating a physical memory space associated with the virtual machine in the machine memory, wherein a size of the physical memory space is greater than a minimum memory reservation for the virtual machine; creating a swap space associated with the virtual machine in storage, wherein a size of the swap space is less than or equal to the difference between a size of the virtual memory space and the minimum memory reservation for the virtual machine; completing the power-on procedure of the virtual machine; and subsequent to completing the power-on procedure of the virtual machine, iteratively allocating storage blocks to the swap space associated with the virtual machine and decreasing a size of the physical memory space associated with the virtual machine.