Copy-based Recovery and Risk Handling Measures

If service data at the production center is lost or corrupted, you can use copies created during protection to roll back and restore data.

If copies, currently protected objects, and used storage resources are changed, risks may arise during copy-based recovery. Table 1 describes the risks and provides handling measures.

In Table 1, A, B, and C represent protected objects. (A1, A2), (B1, B2, B3), and (C1, C2) represent storage resources used by A, B, and C.

**Table 1** Copy-based recovery and risk handling measures
Scenario	Copy Point in Time	Current Point in Time	Restored	Possible Risk	Handling Measure
The protected objects and their storage resources are not changed.	A: A1, A2 B: B1, B2	A: A1, A2 B: B1, B2	Yes	None	-
A new storage resource is added for a protected object.	A: A1, A2 B: B1, B2	A: A1, A2 B: B1, B2, B3 NOTE: New storage resource B3 is added for protected object B.	Yes	If the protected object is a database, the database may fail to be started during recovery because the configuration of the local database is changed.	Manually restart the database after the database configuration becomes consistent with the database at the copy point in time.
The storage resource of a protected object is removed.	A: A1, A2 B: B1, B2	A: A1, A2 B: B1 NOTE: Storage resource B2 of protected object B is removed.	No. The removed storage resource may be used by other applications.	During recovery, application data on removed storage resource B2 may be overwritten by the recovery data.	Manually restore data to the copy point in time based on site conditions.
Protected objects are no longer protected.	A: A1, A2 C: A1, A2 B: B1, B2	A: A1, A2 NOTE: Protected objects B and C are no longer protected. C and A share storage resources A1 and A2.	No	Since protected object B is removed, application data on B is overwritten after recovery.	Manually restore data to the copy point in time based on site conditions.
New protected objects are added.	A: A1, A2	A: A1, A2 B: A1, A2 C: C1, C2 NOTE: New protected objects B and C are added. B and A share storage resources A1 and A2.	Yes	After recovery, application data on protected object B is overwritten and protected C is not started or services on it are stopped. The running of operations on protected objects B and C may affect the recovery of applications on protected object A.	Restore services on protected object C or remove it from the protected group. Manually handle errors that occur during recovery until protected object A is restored successfully. For example, manually disable applications on B and C.