1. A system for mapping storage locations of files in a base virtual machine image and an updated virtual machine image to facilitate page sharing, the system comprising: a virtual image analyzer comprising computer hardware, the virtual image analyzer configured to: identify updates comprising changes to be made to a base virtual machine image stored in first data storage, map unchanged files in the base virtual machine image with first storage locations in the first data storage to produce a first file map, apply the changes to the base virtual machine image to create an updated virtual machine image, the updated virtual machine image being stored in second data storage having second storage locations corresponding to the unchanged files, wherein at least some of the second storage locations are different from the first storage locations, map the unchanged files in the updated virtual machine image with the second storage locations in the second data storage to produce a second file map, relate the first storage locations from the first file map with corresponding ones of the second storage locations from the second file map to produce a storage map, and use the storage map to create one or more tags between the first storage locations and the second storage locations; and a page sharing module configured to use the one or more tags to share memory pages between the base and updated virtual machine images.