Couple of facts that might help you with your backup strategy:
- SMO integrates with Protection Manager to replicate the local app consistent backups created by SMO on the primary to a secondary storage system. You can then restore these protected backups from secondary back to primary anytime using SMO. you can also clone these protected backups on the secondary storage system to isolate your dev/test clones from the primary storage system.
- SMO has NO DR/Failover capabilities. So although SMO can protect backups to a secondary storage system via the integration with Protection Manager it does not provide any failover capabilities.
- Starting from version 3.0.1, SMO supports back up and cloning of 10gR2 Data Guard physical standby databases with the following restirctions as mentioned in the 3.0.1 release notes:
- Using SnapManager 3.0.1 for Oracle, you can backup and clone Oracle 10gR2 (10.2.0.4) physical standby databases created using Oracle Data Guard services. Using Data Guard, DBAs can switch a primary database to a standby mode and vice versa. Only full offline backups and clones of physical standby (standalone and RAC) databases are supported.
- Online backups of standby databases are not supported.
- Partial backups of standby databases are not supported.
- Restore of standby databases are not supported.
- Logical standby databases are not supported.
So currently using SMO, you can only perform offline backups of the standby to primarily clone from those backups for dev/test/reporting. You cannot restore the backups of the standby. So if you want to backup the standby on the secondary for the purpose of restores - then you cannot do this using SMO.
Having stated the facts, you could go with your suggestion of "just run SMO on the primary and let PM/SnapVault copy backups to the secondary DC and not do anything on the DataGuard copy." Since you are leveraging the integration between SMO and PM, you will then be able to clone the SnapVaulted backups on the secondary using SMO if required for dev/test. The standby in this case would then be used for failover/DR scenarios only.
The Oracle Dev/Test Reference Architecture discusses how Data Guard and SMO can be leveraged to replicate data from a non-NetApp storage system to a NetApp storage system and then backup the standby db on the NetApp storage using SMO and then clone those backups using SMO for dev/test/reporting.