All of the backup job templates that are created for synthetic backup and true image restore must have the option Collect additional information for synthetic backup and for true image restore selected. This option can be selected on the General page on the backup job template properties when a policy is being created.

This option specifies that Backup Exec collects the information required to detect files and directories that have been moved, renamed, or newly installed since the last backup, and then includes those files and directories in the backup jobs. This option also lets Backup Exec keep track of deleted files so that they are not included in true image restore of the corresponding backup sets, and are not included in the backup sets created by synthetic backup.

If this option is not selected, Backup Exec skips these files and directories if their archive bits are unchanged. If this option is selected, Backup Exec compares path names, file names, modified times, and other attributes with those from the previous full and incremental backups. If any of these attributes are new or changed, then the file or directory is backed up.

For synthetic backup, the first backup that is associated with the synthetic backup always backs up all of the files, even if it is an incremental backup. Backup Exec starts collecting the additional information with this first backup, but does not compare it to any previous backup.