Image-level backup (image copies) is equivalent to copying copies of data files and archive logs. It is exactly the same as the original file in the storage space. If you need to perform partial recovery (such as a data file) when using image backup, you only need to retrieve the corresponding image, and the recovery speed is very fast. In some situations, you can directly switch to the image data file to ensure that the production environment is stopped for as short as possible, and copy the file to the original path afterwards, and select swich to go back again in idle time.
Since image backup needs to occupy the same space as the production data file, we do not recommend this solution when the data volume is large, because this solution requires the customer to spend double storage costs, however, if the data file is not large at the beginning of a database, or the data volume of a database is always small, it is an excellent solution to influence backup, you can restore the media in the shortest time when the data file is physically damaged.
The following describes some of the simplest RMAN image backup solutions.
1. Enable rman block Tracking Technology
SQL> alter database enable block change tracking using file '/u01/app/oralce/oradata/orcl/block_change_track_file.f ';
Database altered.
2. Perform level 0 backup at the image level
Run {
Allocate channel "identifier" device type disk format "/u04/% U ";
Backup as copy tag 'base01'
Incremental level 0
DATABASE;
}
3. Perform level 1 backup at the image level
$ Rman target/
Run {
Allocate channel "identifier" device type disk format "/u04/% U ";
Backup tag 'incr _ Update'
Incremental level 1
DATABASE;
}
4. Use level 1 backup to update the image in level 0
Run {
Allocate channel "identifier" device type disk format "/u04/% U ";
Recover copy of database with tag 'base01 ';
}
Lab records
1. level 0
RMAN> run {
Allocate channel "identifier" device type disk format "/u04/% U ";
Backup as copy tag 'base01'
Incremental level 0
DATABASE;
}
2> 3> 4> 5> 6>
Released channel: ORA_DISK_1
Allocated channel: allocated
Channel identifier: SID = 32 device type = DISK
Starting backup at 05-SEP-13
Channel metadata: starting datafile copy
Input datafile file number = 00001 name =/u01/app/oralce/oradata/orcl/system01.dbf
Output file name =/u04/data_D-ORCL_I-1349053318_TS-SYSTEM_FNO-1_0coj3jug tag = BASE01 RECID = 18 STAMP = 825348067
Channel completed: datafile copy complete, elapsed time: 00:00:25
Channel metadata: starting datafile copy
Input datafile file number = 00002 name =/u01/app/oralce/oradata/orcl/sysaux01.dbf
Output file name =/u04/data_D-ORCL_I-1349053318_TS-SYSAUX_FNO-2_0doj3jv9 tag = BASE01 RECID = 19 STAMP = 825348091
Channel completed: datafile copy complete, elapsed time: 00:00:25
Channel metadata: starting datafile copy
Input datafile file number = 00005 name =/u01/app/oralce/oradata/orcl/example01.dbf
Output file name =/u04/data_D-ORCL_I-1349053318_TS-EXAMPLE_FNO-5_0eoj3k02 tag = BASE01 RECID = 20 STAMP = 825348107
Channel completed: datafile copy complete, elapsed time: 00:00:15
Channel metadata: starting datafile copy
Input datafile file number = 00004 name =/u01/app/oralce/oradata/orcl/users01.dbf
Output file name =/u04/data_D-ORCL_I-1349053318_TS-USERS_FNO-4_0foj3k0h tag = BASE01 RECID = 21 STAMP = 825348116
Channel completed: datafile copy complete, elapsed time: 00:00:03
Channel metadata: starting datafile copy
Input datafile file number = 00003 name =/u01/app/oralce/oradata/orcl/undotbs01.dbf
Output file name =/u04/data_D-ORCL_I-1349053318_TS-UNDOTBS1_FNO-3_0goj3k0l tag = BASE01 RECID = 22 STAMP = 825348120
Channel completed: datafile copy complete, elapsed time: 00:00:07
Finished backup at 05-SEP-13
Starting Control File and SPFILE Autobackup at 05-SEP-13
Piece handle =/u01/app/Oracle/product/11.2.0/dbhome_1/dbs/c-1349053318-20130905-00 comment = NONE
Finished Control File and SPFILE Autobackup at 05-SEP-13
Released channel: released
RMAN>
For more details, please continue to read the highlights on the next page:
Recommended reading:
Basic Oracle tutorial-copying a database through RMAN
Reference for RMAN backup policy formulation
RMAN backup learning notes
Oracle Database Backup encryption RMAN Encryption