RMAN recovery from loss of all control files

Posted by Gavin Soorma
On July 3, 2009
0 Comments

SCENARIO – LOSS OF ALL CONTROLFILES (NO CATALOG) To simulate this scenario, we will create and populate a table with some records, recover the database from a loss of all control files and then perform an incomplete recovery until the point of failure. SQL> insert into myobjects select * from myobjects; 919664 rows created. SQL> […]

Posted by Gavin Soorma
On July 3, 2009
1 Comments

MAA best practices dictates that to avoid such scenarios, we should be multiplexing the online redo log files. Each group should have at least 2 members and each member should be located on a different physical disk. Loss of a single current online redo log file will require us to restore the entire database and […]

Posted by Gavin Soorma
On July 2, 2009
3 Comments

SCENARIO – 10g Database Loss of datafile which has not been backed up. CREATE NEW TABLESPACE TEST SQL> create tablespace test datafile ‘/u02/oradata/testdb/test.dbf’ size 10m; Tablespace created. TAKE A BACKUP OF THE DATABASE AT THIS POINT >>>>>>>>> ADD DATAFILE TO TEST TABLESPACE SQL> alter tablespace test add datafile ‘/u02/oradata/testdb/test01.dbf’ size 10m; Tablespace altered. SIMULATE FAILURE […]

Posted by Arjun Raja
On June 30, 2009
1 Comments

BLOCK CHANGE TRACKING From version 10.2 onwards, Oracle have provided a new tool which is very useful to reduce the time of RMAN incremental backups. Prior to 10.2, all incremental backups had to read every single block in the database, and if the block has changed, it was backed up. This meant the RMAN backup […]

Posted by Arjun Raja
On June 29, 2009
0 Comments

FLASHBACK DATABASE Flashback database allows you to rollback database to a time in the past. Useful if you have : 1. Dropped user 2. Truncated table 3. Batch job:Partial changes. PRE-REQUISITE: DATABASE MUST BE IN ARCHIVELOG MODE AND YOU MUST SET FLASHBACK ON( BY DEFAULT IT IS OFF) FLASHBACK LOGS ARE CREATED IN YOUR FLASH_RECOVERY_AREA […]

Recovery from a backup taken before a RESETLOGS

Posted by Gavin Soorma
On June 28, 2009
0 Comments

Simulate loss of redo log files [oracle@itlinuxdevblade08 opsdba]$ rm redo*.log Check alert log Errors in file /u02/ORACLE/opsdba/bdump/opsdba_arc1_29898.trc: ORA-00313: open failed for members of log group 1 of thread 1 ORA-00312: online log 1 thread 1: '/u02/ORACLE/opsdba/redo01.log' ORA-27037: unable to obtain file status Linux-x86_64 Error: 2: No such file or directory Additional information: 3 Wed Jun […]

Posted by Gavin Soorma
On June 28, 2009
0 Comments

Original Data Guard Environment HQLINUX05 - PRIMARY ITLINUX03 - STANDBY. Perform FAILOVER TO ITLINUX03 (now the new Primary) Next in ITLINUX03 ..... Step 1: On the new primary, run the following query to determine at what SCN it became the new primary. bozo:/u01/ORACLE/bozo> sql SQL*Plus: Release 10.1.0.2.0 - Production on Mon May 9 14:48:57 2005 […]

Posted by Gavin Soorma
On June 28, 2009
0 Comments

From Oracle 9i onwards you can use RMAN to recover only blocks while database is up and running. This could possibly save hours and hours of recovery time as a full database restore is not necessary. Error reported by user pointing to block corruption. POPULATE_MACSDATA - ORA-01578: ORACLE data block corrupted (file # 48, block […]

Posted by Arjun Raja
On June 25, 2009
1 Comments

To clear the saved configuration in rman – example the configuration for Channel 1 RMAN> CONFIGURE CHANNEL 1 DEVICE TYPE DISK CLEAR; starting full resync of recovery catalog full resync complete old RMAN configuration parameters: CONFIGURE CHANNEL 1 DEVICE TYPE DISK FORMAT ‘/ora_export/backup/fin/%U’ MAXPIECESIZE 16 G; old RMAN configuration parameters are successfully deleted starting full […]

Posted by Arjun Raja
On June 25, 2009
1 Comments

USING RMAN REPAIR ADVISOR: Export ORACLE_SID=test1 sqlplus “sys as sysdba” Shutdown immediate. Go to c:\app\bb16872\test1 and rename SYSTEM01.DBF to SYSTEM01.old Next try to startup database…will fail with error that SYSTEM01.DBF is missing. Y:\>rman target / Recovery Manager: Release 11.1.0.6.0 – Production on Wed Apr 30 10:51:03 2008 Copyright (c) 1982, 2007, Oracle. All rights reserved. […]

Posted by Gavin Soorma
On June 24, 2009
0 Comments

11g New Feature – Standby Database creation from active database without having to take a backup …. Note the command output – APEXDG is created by copying the datafiles directly from an open database APEX without having to restore the backup from tape RMAN> run { allocate channel c1 type disk; allocate auxiliary channel c2 […]

Posted by Gavin Soorma
On June 24, 2009
1 Comments

By using a combination of Oracle 10g Block Change Tracking and RMAN Optimised Incremental Backups we can significantly reduce backup durations and more importantly restore and recover time. The optimised incremental backup will ensure that subsequent incremental backups after a full backup only contain blocks changed since the last backup and will also apply archive […]

Posted by Gavin Soorma
On June 19, 2009
0 Comments

CREATE GLOBAL SCRIPT full_backup { BACKUP DATABASE PLUS ARCHIVELOG; DELETE FORCE NOPROMPT OBSOLETE; } Script can also be created from existing files as well …… CREATE GLOBAL SCRIPT full_backup FROM FILE ‘backup_db.rcv’; For each registered database then : RUN { EXECUTE GLOBAL SCRIPT full_backup; }

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News

RMAN recovery from loss of all control files

RMAN recovery from loss of all online redo log files

Recovery From Loss Of Datafile For Which No Backup Is Available

Enable block change tracking

FLASHBACK DATABASE

Recovery from a backup taken before a RESETLOGS

Using FLASHBACK after a Data Guard Failover

RMAN Block Recovery

RMAN – Clear Saved Configuration

11g RMAN REPAIR ADVISOR

11g Standby Database creation without a backup

10g optimized incremental backups to disk

Using GLOBAL Scripts in RMAN