Funny "ORA-01017: invalid username/password; logon denied" during DataGuard switchover operation from DG broker

Recently one of my customers encountered a problem when they tried to perform a switchover from DataGuard broker command line interface.

$ dgmgrl /
DGMGRL for Linux: Version - 64bit Production

Copyright (c) 2000, 2013, Oracle. All rights reserved.

Welcome to DGMGRL, type "help" for information.
Connected as SYSDG.
DGMGRL> show configuration;

Configuration - db12c

  Protection Mode: MaxPerformance
  db12c  - Primary database
    sdb12c - Physical (more...)

"ORA-16047 – DGID mismatch between destination setting and target database" while configuring dataguard.

While setting up dataguard configuration you may encounter ORA-16047 - DGID mismatch between destination setting and target database.

From alert.log on primary database:

LGWR: Setting 'active' archival for destination LOG_ARCHIVE_DEST_2
Sat Dec 31 08:29:30 2016
FAL[server, ARC3]: Error 16047 creating remote archivelog file 'sauxmes'
FAL[server, ARC3]: FAL archive failed, see trace file.
ARCH: FAL archive failed. Archiver continuing
ORACLE Instance auxmes - Archival Error. Archiver continuing.
Error 16047 for archive log file (more...)

Maintaining Tempfile in TEMP Tablespace of PDB$SEED in Oracle 12c (

During testing recovery procedures for one of the ongoing projects I wanted to test the "complete disaster" recovery scenario. In this scenario I had to recreate also all ASM disks and restore everything from backup.
Actually full backup with RMAN and subsequent restore of a pluggable 12c single-tenant database  was the solution. I will not talk about that as the main point of this post is quite different.

So the recovery was successful but after (more...)