OCI - Enable DG Failed with errors - *RMAN duplicate is failing on Standby*, ...

刘泽宇

OCI - Enable DG Failed with errors - *RMAN duplicate is failing on Standby*, *DCS-10001:Internal error encountered: Unable to duplicated primary db using rman active.*

SYMPTOMS
As per DCS Agent log, enable DG failed during RMAN duplication phase.

*RMAN duplicate is failing on Standby*
*DCS-10001:Internal error encountered: Unable to duplicated primary db using rman active.*
When they connected to the DG instance (before completing the DG association) they observed-

SQL*Plus: Release 18.0.0.0.0 - Production on Mon Apr 27 09:46:24 2020
Version 18.9.0.0.0

Copyright (c) 1982, 2018, Oracle. All rights reserved.

Enter password:
Connected to an idle instance.

SQL> startup mount
ORA-00821: Specified value of sga_target xxxxM is too small, needs to be at least xxxxxM
ORA-01078: failure in processing system parameters
SQL>


CAUSE
This is similar to Bug 30311032, which was closed as not a Bug.
We observed that the customer modified the SGA components there, which was causing this issue.

In this case, we identified that the problem was due to these 2 parameters:

db_2k_cache_size
db_32k_cache_size

DG was building with SGA 2G but the modified values of these two caches were exceeding 2G, which caused the issue here.

SOLUTION
Here we recommended creating a dummy instance in the same shape of this impacted DBCS instance and then compare the parameter values.
During comparison we identified that the below parameters were modified and then they reverted them

db_2k_cache_size
db_32k_cache_size

And then the DG configuration completed successfully.