Basic Principles and Solutions of OracleRMAN image backup (Imagecopies)

Last Update:2018-07-09 Source: Internet

Author: User

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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 customers to spend dual storage

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