Abstract: A method and apparatus for storing on centralized mass storage devices archival data from multiple computers in a networked environment. In a networked computer system having a communication network interconnecting one or more computers and a storage unit, parallel processes are created to perform repeated backup operations for disks on computer devices on the communication network. The backup operations for a disk include a backup initialization which occurs when a primary storage device does not have a full index or a backup data file for a disk but a secondary storage device does. During a backup initialization, data from the files and directories on that disk along with an index entry for each file or directory are passed to the primary storage device which directly passes that information directly through to the secondary storage device. The index entries are incorporated into a full index and the data is incorporated into a backup data file.