A method and system for fast file initialization is provided. An initialization request to create or extend a file is received. The initialization request comprises or identifies file template metadata. A set of allocation units are allocated, the set of allocation units comprising at least one allocation unit for the file on a primary storage medium without initializing at least a portion of the file on the primary storage medium. The file template metadata is stored in a cache. The cache resides in at least one of volatile memory and persistent flash storage. A second request is received corresponding to a particular allocation unit of the set of allocation units. Particular file template metadata associated with the particular allocation unit is obtained. In response to the second request, at least a portion of a new allocation unit is generated.