Applies to:

Oracle Server - Standard EditionOracle Server - Personal EditionOracle Server - Enterprise Edition - Version: 9.0.1.0 and later [Release: 9.0.1 and later]Information in this document applies to any platform.

Purpose

The purpose of this document is to give a quick guide about how to perform Backup and Recovery on RAC databases. We will follow this points:1. Verify the database mode and archive destination.2. Verify connectivity using sqlnet for target and catalog.3. Determine your backup Device.4. Understand how to create an RMAN persistent configuration for a RAC env.5. Create backups to disk using the new persistent configuration parameters.6. Backupset Maintenance using the configured retention policy.7. Restore and Recover a. Complete b. Incomplete8. Review and understand the impact of resetlogs on the catalog.9. RMAN Sample Commands.

Scope and Application

This discussion is for a 2-node Oracle RAC Cluster.The logs are being archived to their respective node.We are allocating channels to each node to enable the autolocate feature of RMAN in a RAC env.

RMAN: RAC Backup and Recovery using RMAN

1. Verify the databases are in archivelog mode and archive destination.

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a. NODE 1: thread 1SQL> archive log list;Database log mode Archive ModeAutomatic archival EnabledArchive destination /u02/app/oracle/product/9.2.0/dbs/archOldest online log sequence 20Next log sequence to archive 21Current log sequence 21b. NODE 2: thread 2

SQL> archive log list;Database log mode Archive ModeAutomatic archival EnabledArchive destination /u02/app/oracle/product/9.2.0/dbs/archOldest online log sequence 8Next log sequence to archive 9Current log sequence 9

2. Verify connectivity to the target nodes and catalog if used. $ setenv TNS_ADMIN $ORACLE_HOME/network/admin $ sqlplus /nolog SQL> connect sys/pwd@node1 as sysdba SQL> connect sys/pwd@node2 as sysdba SQL> connect rman/rman@rcat

3. Set your testing areas.Testing HOME for logs: /u02/home/usupport/rmanBackups HOME Location: /rman/V920

4. Connect using RMAN to verify and set the controlfile persistent configuration.The controlfiles are shared between the instances so configuring the controlfile on node 1 also sets it for all nodes in the RAC cluster. * Always note the target DBID

connected to target database: V920 (DBID=228033884) * Default Configuration RMAN> SHOW ALL; CONFIGURE RETENTION POLICY TO REDUNDANCY 1; # default CONFIGURE BACKUP OPTIMIZATION OFF; # default CONFIGURE DEFAULT DEVICE TYPE TO DISK; # default CONFIGURE CONTROLFILE AUTOBACKUP ON; CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE DISK TO '%F'; # default CONFIGURE DEVICE TYPE DISK PARALLELISM 1; # default CONFIGURE DATAFILE BACKUP COPIES FOR DEVICE TYPE DISK TO 1; # default CONFIGURE ARCHIVELOG BACKUP COPIES FOR DEVICE TYPE DISK TO 1; # default CONFIGURE MAXSETSIZE TO UNLIMITED; # default CONFIGURE SNAPSHOT CONTROLFILE NAME TO '/u02/app/oracle/product/9.2.0/dbs/snapcf_V9201.f'; # default

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* Make changes to the default that fit your business requirements. Note the retention policy can be set "TO REDUNDANCY x" or it can be set "TO RECOVERY WINDOW OF x DAYS", this is new in Oracle9i. In this example, using PARALLELISM 2 as 2 nodes are used. The PARALLELISM will than automatically start 2 channels and will use the related CONFIGURE CHANNEL for additional clauses. CONFIGURE RETENTION POLICY TO REDUNDANCY 3; CONFIGURE BACKUP OPTIMIZATION OFF; CONFIGURE DEFAULT DEVICE TYPE TO DISK; CONFIGURE CONTROLFILE AUTOBACKUP ON; CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE DISK TO '/rman/V920/%F'; CONFIGURE DEVICE TYPE DISK PARALLELISM 2; CONFIGURE DATAFILE BACKUP COPIES FOR DEVICE TYPE DISK TO 1; CONFIGURE ARCHIVELOG BACKUP COPIES FOR DEVICE TYPE DISK TO 1; CONFIGURE MAXSETSIZE TO UNLIMITED; CONFIGURE SNAPSHOT CONTROLFILE NAME TO '/rman/V920/snapcf_V92321.f'; CONFIGURE CHANNEL 1 DEVICE TYPE DISK connect 'SYS/rac@node1'; CONFIGURE CHANNEL 2 DEVICE TYPE DISK connect 'SYS/rac@node2';

* Review/Verify your new configuration.

RMAN> SHOW ALL; CONFIGURE RETENTION POLICY TO REDUNDANCY 3; CONFIGURE BACKUP OPTIMIZATION OFF; CONFIGURE DEFAULT DEVICE TYPE TO DISK; CONFIGURE CONTROLFILE AUTOBACKUP ON; CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE DISK TO '/rman/V920/%F'; CONFIGURE DEVICE TYPE DISK PARALLELISM 2; CONFIGURE DATAFILE BACKUP COPIES FOR DEVICE TYPE DISK TO 1; CONFIGURE ARCHIVELOG BACKUP COPIES FOR DEVICE TYPE DISK TO 1; CONFIGURE CHANNEL 1 DEVICE TYPE DISK CONNECT 'SYS/rac@node1'; CONFIGURE CHANNEL 2 DEVICE TYPE DISK CONNECT 'SYS/rac@node2'; CONFIGURE MAXSETSIZE TO UNLIMITED; CONFIGURE SNAPSHOT CONTROLFILE NAME TO '/rman/V920/snapcf_V92321.f';

5. Make a backup using the new persistent configuration parameters.* Backup database with differential incremental 0 and then archived logs using the delete input option.

BACKUP INCREMENTAL LEVEL 0 FORMAT '/rman/V920/%d_LVL0_%T_%u_s%s_p%p' DATABASE; BACKUP ARCHIVELOG ALL FORMAT '/rman/V920/%d_AL_%T_%u_s%s_p%p'DELETE INPUT;

* Backup again using differential incremental level 1

BACKUP INCREMENTAL LEVEL 1 FORMAT '/rman/V920/%d_LVL1_%T_%u_s%s_p%p' DATABASE; BACKUP ARCHIVELOG ALL FORMAT '/rman/V920/%d_AL_%T_%u_s%s_p%p' DELETE INPUT;

* To simplify this from Oracle9i we can also use PLUS ARCHIVELOG BACKUP INCREMENTAL LEVEL 0 FORMAT '/rman/V920/%d_LVL0_%T_%u_s%s_p%p' DATABASE PLUS ARCHIVELOG FORMAT '/rman/V920/%d_AL_%T_%u_s%s_p%p' DELETE INPUT; This uses a different algorithm than backup database and backup archivelog in separate commands, the algorithm for PLUS ARCHIVELOG is: 1. Archive log current 2. Backup archived logs 3. Backup database level 0 4. Archive log current 5. Backup any remaining archived log created during backup

6. Backup set Maintenance using the configured retention policy RMAN> LIST BACKUP SUMMARY; RMAN> LIST BACKUP BY DATAFILE; RMAN> LIST BACKUP OF DATABASE; RMAN> LIST BACKUP OF ARCHIVELOG ALL; RMAN> LIST BACKUP OF CONTROLFILE; These above can be enhanced with the "until time" clause as well as the archivelog backups using "not backed up x times" to cut down on many copies of a log in several backup sets. Then continuing with SMR Server Managed Recovery use the change archivelog from...until...delete to remove old logs no longer needed on disk. To check/delete obsolete backups or archivelogs we use: RMAN> REPORT OBSOLETE; RMAN> DELETE OBSOLETE; or RMAN> DELETE NOPROMPT OBSOLETE; To check the database files: RMAN> REPORT SCHEMA;

7. Restore and Recover Complete Recovery With the database mounted on the node1 and no-mount on node2 connect to the target and catalog using RMAN. rman target / catalog rman/rman@rcat This script will restore and recover the database completely and open. All previous backup will still be available for use because there was not RESETLOGS command given. run { RESTORE DATABASE; RECOVER DATABASE; ALTER DATABASE OPEN;

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} Incomplete RecoveryIf you are using instance registration the database must be mounted to register with the listener. This means you must use the current controlfile for restore and recovery or setup a dedicated listener if not already done. RMAN requires a dedicated server connection and does not work with using instance registration before mounting the controlfile.Using the autobackup controlfile feature requires the DBID of the TARGET database. It must be set when the database is not mounted and only the controlfile and spfile (from 9.2) can be restored this way.

1. Shutdown node1 and node2 2. Startup no-mount node2 and node1 3. Start rman rman trace reco1.log RMAN> CONNECT CATALOG rman/rman@rcat RMAN> SET DBID=228033884; RMAN> CONNECT TARGET 4. Restore the controlfile from autobackup % rman trace recocf.log RMAN> SET DBID=228033884; RMAN> CONNECT TARGET RMAN> RUN { SET CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE disk TO '/rman/V920/%F'; ALLOCATE CHANNEL d1 DEVICE TYPE disk; RESTORE CONTROLFILE FROM AUTOBACKUP MAXSEQ 5 # start at sequence 5 and count down (optional) MAXDAYS 5; # start at UNTIL TIME and search back 5 days (optional) MOUNT DATABASE; }

5. Verify what is available for incomplete recovery. We will recover with the highest available redo information. In a RAC database, both thread must be considered to determine highest available redo. The options are "until time", "until scn", or "until sequence". We will use the log sequence in this case. * First we need to find the highest sequence of each thread: SQL> select max(sequence#) from v$archived_log where thread#=1; MAX(SEQUENCE#)

-------------- 25 SQL> select max(sequence#) from v$archived_log where thread#=2; MAX(SEQUENCE#)

-------------- 13 * Next is to find the thread with lowest NEXT_CHANGE# scn. In this case the next_change# SCN in thread 1 sequence 25 is lower than sequence 13 thread 2. In a RAC environment, we use the lower to ensure we have the redo required from BOTH threads. In other words, we use the lower (thread# 1) to ensure that ALL scn (s) in thread #1 exist in the available sequence for thread #2. So we will set sequence 26 for thread 1 for RMAN 'until sequence' recovery, because RMAN stops the recovery before applying the indicated sequence. Log sequence for recovery needs always be sequence+1 to end at +1 after applying the prior sequence. SQL> select sequence#, thread#, first_change#, next_change# from v$archived_log where sequence# in (13,25); SEQUENCE# THREAD# FIRST_CHANGE# NEXT_CHANGE#

-------------------- -------------- ------------------------- ------------------------- 25 1 1744432 1744802 13 2 1744429 1744805 SQL> select sequence#, thread#, first_change#, next_change# from v$backup_redolog where sequence# in (13,25); SEQUENCE# THREAD# FIRST_CHANGE# NEXT_CHANGE#

-------------------- -------------- ------------------------- ------------------------- 25 1 1744432 1744802 13 2 1744429 1744805

--- SET UNTIL SEQUENCE 26 THREAD 1 ---- 6. Get the sentences to add TEMPFILES after opening DB.Locally Managed Temporary Tablespaces are not restored by RESTORE command, we need to create them manually after recovery is complete.If using LMT Temporary tablespace the controlfile will have the syntax to add the tempfile after recovery is complete. The following command will give us the create controlfile sencence: SQL> alter database backup controlfile to trace; Example: # Commands to add tempfiles to temporary tablespaces. # Online tempfiles have complete space information. # Other tempfiles may require adjustment. ALTER TABLESPACE TEMP ADD TEMPFILE '/dev/db/rV92B_temp_01.dbf' SIZE 41943040 REUSE AUTOEXTEND OFF; # End of tempfile additions. # 7. Run the rman scriptSince log sequence 13 thread 2 next_change# is 3 changes ahead of thread 1 sequence 25 we are using sequence 14 to stop recovery. This will restore the data files and recover them completely using the online logs. run { SET UNTIL SEQUENCE 26 THREAD 1; RESTORE DATABASE; RECOVER DATABASE; ALTER DATABASE OPEN RESETLOGS; }Finally add the tempfiles with sentences from step 6.

8. Review and understand the impact of resetlogs on the catalog.After resetlogs there are 2 incarnations in the recovery catalog. Only one incarnation can be current at one time for a given DBID. The Inc Key keeps track of the database incarnations.RMAN> LIST INCARNATION OF DATABASE V920;List of Database IncarnationsDB Key Inc Key DB Name DB ID CUR Reset SCN Reset Time----------- ----------- ------------ ---------------- ------- -------------- ---------------

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2656 2657 V920 228033884 NO 1 29-MAY-032656 3132 V920 228033884 YES 1744806 13-JUN-03

9. RMAN Sample Commands* With a dedicated listener (not using instance registration) restoring the controlfile. run { ALLOCATE CHANNEL D1 TYPE DISK CONNECT 'SYS/RAC@NODE1'; ALLOCATE CHANNEL D2 TYPE DISK CONNECT 'SYS/RAC@NODE2'; SET UNTIL SEQUENCE 14 THREAD 2; RESTORE CONTROLFILE; ALTER DATABASE MOUNT; RELEASE CHANNEL D1; RELEASE CHANNEL D2; } * Backup Archivelog BACKUP ARCHIVELOG ALL NOT BACKED UP 3 TIMES; BACKUP ARCHIVELOG UNTIL TIME 'SYSDATE-2' NOT BACKED UP 2 TIMES;

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