Experiments in Geekery

[oracle@target dbs]$ rman auxiliary sys@dup target sys@source [...] RMAN> duplicate target database to DUP from active database db_file_name_convert '/u2/data/PROD','/u2/data/DUP' LOG_FILE_NAME_CONVERT '/u2/data/PROD/onlinelog','/u2/data/DUP' nofilenamecheck; Starting Duplicate Db at 25-FEB-15 using target database control file instead of recovery catalog allocated channel: ORA_AUX_DISK_1 channel ORA_AUX_DISK_1: SID=171 device type=DISK RMAN-00571: =================================================== RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ======= RMAN-00571: =================================================== RMAN-03002: failure of Duplicate Db command at 02/25/2015 16:04:44 RMAN-05501: aborting duplication of target database RMAN-05531: a mounted database cannot be duplicated while datafiles are fuzzy Using Oracle 11.2.0.3 (anything below 11.2.0.3.6), this is the error if an attempt is made to duplicate from an activ...

Last week, we initiated a planned switchover of our primary and standby dataguard instances.  11.2.0.3, physical standby.  Dead easy. The database change went absolutely perfectly.  No problems.  Brilliant.  A 5 step process and everything did as the Oracle docs said they should. The problem... the problem was everything else. Some background: The company has been using active data guard to populate a read-only standby for about 9 months, and since it was installed have never done a switchover (or a failover).  Almost all client jobs are cron- & script-based (running on the DB host), or run manually. A week before the switch, I'd gone through a list of apps with a senior developer and checked that they all referenced a DNS name rather than an IP address.  That's a relatively short list of about 10 apps of various types and sizes. Come the switch, most things went as smoothly as you'd hope!  The vast majority of the Tomcat apps switch...