Patent ID: 8479198

Claim:
A non-transitory computer readable medium comprising a hypervisor, which is executed on a server apparatus having a physical memory and a physical processor, comprising: a write controller configured to control a write from the physical processor to a physical area; and an area manager configured to manage a physical allocation area, which is a storage area that is allocated to a virtual machine from within the physical memory, and which is configured from a plurality of physical areas, (A) wherein the write controller is configured to set all the physical areas configuring the physical allocation area to a write protect mode; (B) wherein, after step (A), when the physical processor has identified that a write-destination area, which is the physical area specified in a write request issued by the virtual machine, is in the write protect mode, (b1) the area manager is configured to perform the step of managing the write-destination area as an updated area, and, (b2) the write controller is configured to perform the step of canceling the write protect mode of the write-destination area; (C) wherein the area manager is configured to perform the step, after step (A), at the time of a snapshot acquisition, of copying data in the updated physical area, from among all the physical areas configuring the physical allocation area, to a copy area, which is a storage area that is different from the physical allocation area, and wherein the area manager is configured to perform the step, subsequent to step (C), of managing the updated physical area as an updated area and as a non-updated area, and to perform step (A) again; and (D) when the occurrence of a prescribed failure in a physical area has been detected, the area manager is configured to perform the step of restoring data from the copy area that stores a copy of the data stored in a failure area, which is the physical area in which the prescribed failure has occurred, and when the occurrence of a prescribed failure in the physical area is detected, and the failure area is managed as a non-updated area, the area manager is configured to perform the step of identifying a privilege level of the physical processor at the time the prescribed failure has occurred, and to carry out processing in accordance with this privilege level.