How catalog incrementals and standard backups interact on UNIX

A catalog backup policy can include both full catalog backups and incremental catalog backups. However, incremental catalog backups differ from incremental standard backups. Catalog backups use both mtime and ctime to identify changed data. Standard incremental backups use only mtime to identify changed data.

Because of this difference, running a standard policy type backup that includes the /usr/openv/netbackup/db/images/ directory can adversely affect incremental catalog backups. When standard backups run, they reset the file access time (atime). In turn, the reset changes the ctime for files and directories. If an incremental catalog backup runs, it sees that the ctime has changed and backs up the files. The backup may be unnecessary since the files may not have changed since the last catalog backup.

To avoid additional processing during catalog backups, the following is recommended:

If incremental catalog backups are configured, exclude the NetBackup /usr/openv/netbackup/db/images/ directory from standard backups.

To exclude that directory, create a /usr/openv/netbackup/exclude_list file on the primary server.