1. A method for configuring a virtual image instance in a plurality of networked nodes or clusters, comprising: receiving, at a storage optimizer, a configuration file, in XML or another markup language that defines a set of rules for encoding description of data in one or more documents, specifying software information corresponding to a desired virtual machine instance that is to be instantiated on a node or cluster of the plurality of networked nodes or clusters that is prepared by a cloud controller, the software information including an IP address of a first service that provides raw block devices configured to attach to a virtual machine; connecting, by the storage optimizer, to the first service by utilizing the IP address provided in the configuration file; downloading, by the storage optimizer, from a storage service to the first service, software and data images specified by the configuration file; disconnecting the storage optimizer from the first service following completion of the download; and connecting the first service to the node or cluster and transferring, by the first service, the software and data images to the node or cluster.