1. A method comprising: receiving, at a computer system, a request to create a snapshot of a virtual storage device, wherein the virtual storage device virtually stores data at virtual addresses, the data being physically stored at a plurality of physical storage locations that are managed by an underlying storage system associated with virtual storage device, the plurality of physical storage locations being associated with physical addresses and being distributed across a plurality of physical storage devices, the underlying storage system managing storage of the data across the plurality of physical storage devices using unique identifiers that are: i) independent of the plurality of physical storage devices and the plurality of physical storage locations and ii) different from the virtual addresses; identifying, by the computer system, one or more regions of the virtual storage device that have been written to since a previous snapshot of the virtual storage device was created, wherein data written to the one or more identified regions is stored in the plurality of physical storage locations separately from other stored data that corresponds to other snapshots of the one or more regions; generating a unique identifier for the requested snapshot; and creating the requested snapshot using the identified one more regions and the unique identifier, wherein the requested snapshot includes a mapping of the unique identifier to the one or more identified regions of the virtual storage device and does not include any data stored in the virtual storage device.