Methods and systems for efficiently downloading archived snapshot data from the cloud or from an archival data store are described. In a disaster recovery scenario in which an entire storage appliance for backing up different point in time versions of a virtual machine has failed (e.g., due to a fire), archived snapshot data for the different point in time versions may be acquired by a second storage appliance from an archival data store (e.g., cloud-based data storage) using one or more snapshot mapping files. A snapshot mapping file may include pointers to a plurality of data blocks within the archival data store for generating a full image snapshot associated with a particular point in time version of the virtual machine. The plurality of data blocks may comprise the minimum number of data blocks necessary to construct the particular point in time version of the virtual machine.