When using VSS-2 or VSS-3 with Remote Database Backup, it is recommended, but not required that the same disk pack hardware be used for auditing on both the primary and secondary systems. This optimizes performance at the secondary when using one of the audit file transfer modes (AFS, SCA, or NSC), since audit files created on the primary system will be optimized for the hardware on that system. This is less critical when using the audit block transfer mode ABW, since the audit is optimized for the resident hardware at each system.