This is mostly just to document if you hit similar issues and how to get past them. I had to perform some remote cloning in ExaCS (from one CDB to another CDB) within same VM cluster, but hit few issues which I had to resolve first before getting it to work.
[DBT-05514] Failed to connect to the database
This was the first issue, in the error message I could see following:
[FATAL] [DBAAS-60071] Operation has failed with following error message. [FATAL] [DBT-05514] Failed to connect to the database (mydb-scan.subnet.vcn.oraclevcn.com:1521/CDBDB_t4v_ams.subnet.vcn.oraclevcn.com). CAUSE: Specified connection string (mydb-scan.subnet.vcn.oraclevcn.com:1521/CDBDB_t4v_ams.subnet.vcn.oraclevcn.com) or SYSDBA credential is not valid to connect to the database. ACTION: Specify a valid connection string or SYSDBA credential to connect to the database..
Reason for this was simple, we didn’t have db_domain parameter set so to fix it, set db_domain to whatever your correct value in your VCN is.
alter system set db_domain = 'subnet.vcn.oraclevcn.com'
[DBT-19402] Local undo mode is not enabled
This is quite easy to figure out, local undo mode is needed to be enabled in order for PDB cloning to work. For this you can follow Tim’s great example on his page: https://oracle-base.com/articles/12c/multitenant-local-undo-mode-12cr2
[DBT-05505] Unable to execute sql script
This took some time to figure out, the error said it’s unable to query over DB link what tooling creates for the clone. But when you look the log files through, you can see OCI tooling creates user, role and link but fails with ORA-01017: invalid username/password; logon denied.
Reason for this is that tooling requires the SOURCE database to have sec_case_sensitive_logon set to TRUE (we had it as FALSE at this point in time).
alter system set sec_case_sensitive_logon = TRUE scope=spfile;
Which log files to look for errors
Just for troubleshooting it’s good to know where to look for errors, following log files helped me:
DCS logs, usually start with these: /opt/oracle/dcs/log/dcs-agent-requests.log & /opt/oracle/dcs/log/dcs-agent-0.log
Specific PDB log file location, has more log files specific when you get to PDB cloning: /var/opt/oracle/log/dbaastools/cfgtoollogs/dbca/DESTCDB_1ab_ams/PDB1