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Oracle vDB start fails with ORA-12547: TNS:lost contact (KBA10883)







Starting an Oracle vDB fails with the following error:

Enable dataset "VDB".
Failed to perform verification for virtual database "VDB" on host "" due to error 
" {Exception occurred while getting connection: oracle.ucp.UniversalConnectionPoolException:
Cannot get Connection from Datasource: java.sql.SQLException: ORA-12547: TNS:lost contact
Error Code
Suggested Action
Review and resolve the error and run the operation again.

Applicable Delphix Versions

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This fault can be due to the VDB not being shutdown cleanly. To force a cleanup, complete the following procedure:

In Delphix, ensure the vDB is disabled.

On the target server:

  1. mount | grepVDB (ensure there are no mounted filesystems)
  2. df -h (ensure there are no stale NFS mounts)
  3. ps -ef | grep pmon | grep [VDB] (ensure no pmon is running for the database)
  4. Execute the following to cleanup the stale instance:
export ORACLE_HOME=<path for the oracle home>
$ORACLE_HOME/bin/sqlplus /nolog
SQL> set _prelim on
SQL> conn / as sysdba
Prelim connection established
SQL> shutdown abort



Check the previous shutdown in the Oracle alert log or target connector logs for any shutdown issues:

  1. Example from the previous shutdown attempt captured in the Delphixconnector logs:
ERROR at line 1:
ORA-01012: not logged on
Process ID: 0
Session ID: 0 Serial number: 0'
Database is in bad state.
  1. When connecting to the instance you do not see the expected Connected to Idle Instance.

sqlplus '/as sysdba'
SQL*Plus: Release - Production on Wed Feb 28 08:30:18 2024 Version
Copyright (c) 1982, 2022, Oracle. All rights reserved.
SQL> exit

This occurs even when no Oracle pmon process is running on the target.



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