In one embodiment, a computer accessible medium comprises instructions which, when executed, check a first storage from which a computer system is configured to boot for a block identified in a read request. The block is included within an image of a set of software resources to be provisioned on the computer system. If the block is stored in the first storage, the instructions supply the block from the first storage in response to the read request. Otherwise, the instructions: fetch the block from an image repository system that stores the image; store the block in the first storage; and supply the block in response to the read request. In another embodiment, the instructions store a block identified in a write request to the first storage. The instructions record that the block is modified in the first storage with respect to the image stored in an image repository system.