Abstract: This invention is a system and a method for operating a storage server in a data network using a new architecture. The system of operating a storage server includes a secondary storage that archives or stores a data object in transformed form such that the clients of the storage server can no longer access the data directly. The method of accessing the data object that is archived or transformed in a different form to the secondary storage includes recalling only those data blocks that are required for read or write operation.

Abstract: Implementations are provided herein for incremental backup using a change tree. A change tree is a database file for tracking file system changes of a specific dataset, such as a directory of a file system. A backup process can create and/or initiate a change tree when creating a backup snapshot of a dataset. After the change tree is created, all file system changes inside the dataset can be tracked. The next incremental backup can then take advantage of the change tree to backup changes without traversing the entire dataset. Thus, incremental backups can be more efficient and are better able to keep up with tape streaming speed.