System Programmer Reference › Backing Up Data › Backing Up SFS and BFS Data › Incremental Backup of SFS File Spaces

Incremental Backup of SFS File Spaces

When performing an incremental backup, CA VM:Backup determines whether changes have occurred since a previous backup by computing a special hash value based on the FST attributes, file authorizations, and physical block numbers backed up for each file. CA VM:Backup computes this hash value regardless of the type of change detection the system administrator specifies in the backup job template file.

CA VM:Backup also computes, for the alias files, a separate hash value that contains the fully qualified names of both the alias and base files. The hash value computed for SFS differs from that computed for CMS minidisks in that it does not include the file's contents. If the base catalog contains domain-level detail, the file space contents are hashed.