1. An apparatus for backing up data from a primary storage to a secondary storage, the apparatus comprising: at least one processor; a module identifies data to be backed up from primary storage, including: a first subset of the data to be backed up, which is tagged as an application-level characteristic of user data, and a second subset of the data to be backed up, which is tagged as an application-level characteristics of index data or log data; a module allocates a job for transferring the data from the primary storage to the secondary storage, wherein the secondary storage comprises multiple storage locations; a module divides the job into multiple data streams, wherein each data stream of the multiple data streams has a corresponding data path for carrying data, and is associated with the first subset of the data or the second subset of the data based on the identified application-level characteristics tagged to the data, and wherein each data path is associated with a corresponding and different media agent and a corresponding and different destination storage location from the multiple storage locations of the secondary storage; and a module stores, for each unit of data transferred from the primary storage to the secondary storage, information identifying a primary storage location for the unit of data and a destination storage location at which the unit of data is backed up; and a module transfers the data to be backed up from the primary storage to the secondary storage, wherein the first subset of the data is transferred via first data streams of the multiple data streams that are associated with the first subset of the data based on the identified application-level characteristics of the data, and wherein the second subset of the data is transferred via second, different, data streams of the multiple data streams that are associated with the second subset of the data based on the identified application-level characteristics of the data.