Applies to:
Oracle Database - Enterprise Edition - Version 10.2.0.1 and later
Oracle Database Exadata Cloud Machine - Version N/A and later
Oracle Cloud Infrastructure - Database Service - Version N/A and later
Oracle Database Cloud Exadata Service - Version N/A and later
Oracle Database Exadata Express Cloud Service - Version N/A and later
Information in this document applies to any platform.
Goal
Moving User datafiles between ASM Diskgroups using Incrementally Updated Backups.
Solution
NOTE: In the images and/or the document content below, the user
information and environment data used represents fictitious data from
the Oracle sample schema(s), Public Documentation delivered with an
Oracle database product or other training material. Any similarity to
actual environments, actual persons, living or dead, is purely
coincidental and not intended in any manner.
For the purposes of this document, the following fictitious environment is used as an example to describe the procedure:
Database:
DB_NAME: PROFIT
ASM DISKGROUP : +ASM_DISK1 and +ASM_DISK2
Move datafiles in ASM diskgroups with minimum downtime.
1. Take level 0 datafile copy as a base to the new Diskgroup. This copy has either a system-defined or user-defined tag.
2. Periodically take level 1 differential backups created with the same tag as the level 0 datafile copy.
Use BACKUP FOR RECOVER OF COPY command so that an incremental backup is created containing only blocks
changed since the most recent incremental backup with the same tag.
3. Periodically, apply the incremental backup to the level 0 datafile copy. Because the datafile copy has
been updated with more recent changes, it would require less media recovery.
4. Take the datafile offline.
5. Use RMAN to switch the datafile to the latest image copy.
6. Recover the datafile to make it consistent with the other files.
7. Bring the datafile online.
8. Verify by querying v$datafile and proceed with deleting the old file.
Note:- These steps are not applicable for system or sysaux datafiles
example:-
Query v$datafile for the location of the datafile (6 in this test case)
FILE# NAME STATUS
---------- ---------------------------------------------------------------------- -------
1 +ASM_DISK1/profit/datafile/system.256.766889099 SYSTEM
2 +ASM_DISK1/profit/datafile/undotbs1.258.766889099 ONLINE
3 +ASM_DISK1/profit/datafile/sysaux.257.766889099 ONLINE
6 +ASM_DISK1/profit/datafile/test.275.767269709 ONLINE
1. Making Incrementally Updated Backups
RMAN> BACKUP INCREMENTAL LEVEL 1 FOR RECOVER OF COPY WITH TAG 'incr_update' DATAFILECOPY FORMAT '+ASM_DISK2' datafile 6;
Starting backup at 25-06-2012 18:32:02
using channel ORA_DISK_1
no parent backup or copy of datafile 6 found => This is a level 0 backup as there is no parent backup.
channel ORA_DISK_1: starting datafile copy
input datafile fno=00006 name=+ASM_DISK1/profit/datafile/test.275.767269709
output filename=+ASM_DISK2/profit/datafile/test.272.786911523 tag=INCR_UPDATE recid=25 stamp=786911531
channel ORA_DISK_1: datafile copy complete, elapsed time: 00:00:15
Finished backup at 25-06-2012 18:32:18
RMAN> list copy of datafile 6;
List of Datafile Copies
Key File S Completion Time Ckp SCN Ckp Time Name
------- ---- - ------------------- ---------- ------------------- ----
25 6 A 25-06-2012 18:32:11 1356009 25-06-2012 18:32:03 +ASM_DISK2/profit/datafile/test.272.786911523
SQL> alter system switch logfile;
2. Second time when the command is fired it creates incremental level 1 backups.
RMAN> BACKUP INCREMENTAL LEVEL 1 FOR RECOVER OF COPY WITH TAG 'incr_update' DATAFILECOPY FORMAT '+ASM_DISK2' datafile 6;
Starting backup at 25-06-2012 18:35:19
using target database control file instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: sid=150 devtype=DISK
channel ORA_DISK_1: starting incremental level 1 datafile backupset
channel ORA_DISK_1: specifying datafile(s) in backupset
input datafile fno=00006 name=+ASM_DISK1/profit/datafile/test.275.767269709
channel ORA_DISK_1: starting piece 1 at 25-06-2012 18:35:20
channel ORA_DISK_1: finished piece 1 at 25-06-2012 18:35:27
piece
handle=+ASM_DISK2/profit/backupset/2012_06_25/nnndn1_tag20120625t183519_0.271.786911721
tag=TAG20120625T183519 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:07
Finished backup at 25-06-2012 18:35:27
3. Apply the incremental backup to the level 0 data file copy
RMAN> RECOVER COPY OF DATAfile 6 WITH TAG 'incr_update';
Starting recover at 25-06-2012 18:37:12
using channel ORA_DISK_1
channel ORA_DISK_1: starting incremental datafile backupset restore
channel ORA_DISK_1: specifying datafile copies to recover
recovering datafile copy fno=00006 name=+ASM_DISK2/profit/datafile/test.272.786911523
channel ORA_DISK_1: reading from backup piece
+ASM_DISK2/profit/backupset/2012_06_25/nnndn1_tag20120625t183519_0.271.786911721
channel ORA_DISK_1: restored backup piece 1
piece handle=+ASM_DISK2/profit/backupset/2012_06_25/nnndn1_tag20120625t183519_0.271.786911721 tag=TAG20120625T183519
channel ORA_DISK_1: restore complete, elapsed time: 00:00:02
Finished recover at 25-06-2012 18:37:14
RMAN> list copy of datafile 6;
List of Datafile Copies
Key File S Completion Time Ckp SCN Ckp Time Name
------- ---- - ------------------- ---------- ------------------- ----
26 6 A 25-06-2012 18:37:13 1356106 25-06-2012 18:35:20 +ASM_DISK2/profit/datafile/test.272.786911523
4. Take the datafile offline.
SQL> alter database datafile 6 offline;
5. Switch the datafile to the latest image copy and recover the datafile.
RMAN> switch datafile 6 to copy;
RMAN> recover datafile 6;
6. Bring the datafile online.
SQL> alter database datafile 6 online;
SQL> select file#, name,status from v$datafile;
FILE# NAME STATUS
---------- ---------------------------------------------------------------------- -------
1 +ASM_DISK1/profit/datafile/system.256.766889099 SYSTEM
2 +ASM_DISK1/profit/datafile/undotbs1.258.766889099 ONLINE
3 +ASM_DISK1/profit/datafile/sysaux.257.766889099 ONLINE
6 +ASM_DISK2/profit/datafile/test.272.786911523 ONLINE