If you lose a disk, coserver, or the whole system, you can externally restore data only if it was externally backed up. You must use the same third-party utility for both the external backup and restore. To externally restore the storage spaces, copy the backed-up data to disk. Use the onbar -r -e command to mark the storage spaces as physically restored, replay the logical logs, and bring the storage spaces back online. If you do not specify an external restore command, the database server thinks that these storage spaces are still down.
You can perform these types of external restores:
To salvage logical logs, perform onbar -l -s before you copy the external backup and perform the external restore (onbar -r -e).
In Extended Parallel Server, you must perform a logical restore on the whole system after an external backup even if all the storage spaces were backed up together.