5.18.2013

A tricky standby database situation

A very tricky and interesting situation came-up this morning while configuring one of the standby databases of over 1.5TB sized . Whilst the database is being cloned to the DR site as part of the DUPLICATE..ACTIVE DATABASE command, which actually took more than 1.5 day, a couple of new datafiles were added to the primary database.  After cloning process was over, the newly build DR database was almost 2 days behind withe the primary database. I knew I can make it in SYNC the PRIMARY and STANDBY applying the standby roll-froward method, but, I already have a daily cumulative incremental backups on TAPE.  If I perform incremental backup to do the roll-forward upgrade, it gonna take much time. Hence, I determined to make use of the existing backups. When the the roll-forward method was followed, the following confronted:

RMAN> SWITCH DATABASE TO COPY;

RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of switch to copy command at 05/18/2013 10:25:29
RMAN-06571: datafile 58 does not have recoverable copy


Obviously, it was expected, because the datafile in the question was added after standby database creation initiations.

Workaround:
Had to try out-of-the-box solution (roll-forward method).
  1. Re-create and restore the standby controlfile
  2. Restore missing datafiles on the standby
  3. Catalog standby database datafiles (diskgroup was different from primary)
  4. Recover the database
  5. Complete the rest of the standby configure to make it in sync 
Will be writing a detailed article on this. Stay tuned for more.

Happy reading

Jaffar


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