Backup3G/DA-RMAN/User Guide/Defining Oracle RMAN Backups

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Revision as of 07:18, 23 February 2007

Oracle backups are configured in much the same as other backup jobs:

• you define a backup item for each data object or in this case, Oracle SID, to be backed up
• you define backup jobs to back up one or more items at the scheduled time to a particular drive or drive pool

The main differences are:

• in the backup item you use an Oracle/RMAN-specific backup method instead of one of the standard UNIX methods
• the data object refers to an Oracle SID and not to a filesystem or directory

This section describes the ways you can back up Oracle databases, the Oracle/RMAN-specific backup methods, and how to define backup items. Defining, scheduling, and monitoring backup jobs is described in the backup3G User Guide.

Types of Oracle/RMAN Backup

This topic describes the different methods for backing up Oracle databases.

Oracle/RMAN Backup uses Oracle and Recovery Manager (RMAN) facilities to start up and shut down databases, and to find the names of tablespaces and archived logs to be backed up. Once the object names have been obtained, they are backed up using the RMAN API facility (library) provided as part of DA for Oracle/RMAN.

What happens if a step fails

If any step in the backup job returns a non-zero exit status, the backup job terminates. In this event DA-RMAN does not try to change the database mode or attempt any other recovery action.

You should diagnose the problem to see whether it occurred in an Oracle operation or a backup command, then if possible fix the problem and resubmit the backup job.

‘Exit status 2’ usually indicates a usage error in the backup command, such as an unrecognized option or an incorrect number of arguments. Other exit statuses are dependent on the backup method—check the manual page for the command that reported the error.

Any previous steps that wrote to the tape and completed successfully may be restored from, but depending on the type of backup may not be worth recovering.

The DBA should examine the reason for failure and the type of object in the successful backup steps to see whether they can be usefully recovered.

Two versions of Oracle installed on a host

For each Oracle Instance to be backed up you will need to first define the instances. Each instance maybe owned by a different user and have different connect strings.

Offline Backup

Online Backup

Archive Log Backup

Export Backup

Note

DA-RMAN does not support export at this stage.

Defining Oracle Backups

You must define a backup item for each type of backup that you want to perform on a database instance. For example, if the monthly cycle of backups for a particular database includes online and offline backups, and backups of archived redo log files, you will need to define four backup items.

Once you have defined all your backup items, you must define a set of backup jobs to back up these items at the scheduled times. See How to Define a Backup Job in the backup3G User Guide.

How to Define a Backup Item

A backup item describes the ‘what’ and ‘how’ of a backup. It identifies the host name and Oracle SID, and the method that will be used to back it up.

How you specify the exact Oracle object to be backed up depends on the backup method.

Each backup method calls a driver script to back up the data. Table 2 shows the backup command and other attributes for the Oracle/RMAN backup method.

You can use the Options field to pass extra flags and arguments to the backup command. To see what options are supported by each method, press the Options button on the backup item form.

Note

These options are not validated when you define the backup item, but are simply passed to the backup command to be evaluated at run time.

To define a backup item

1. Select backup3G configuration > Maintain backup jobs.
2. Select Items > Maintain to display the list of existing backup items, then select Maintain > Add.

   Host

   Select the host on which the database is stored. If you want to back up the same database on multiple hosts, you must define a separate backup item for each.

   Folder/Object

   Enter the SID of the instance to be backed up. Make sure that it is correct, as backup3G doesn’t check that it exists at this point.

   Format

   Select 'rman'.

   Method

   Press Choose to list the 'rman' backup methods.

   Options

   Press Options to display RMAN backup options (see below).

   Comment

   Enter a descriptive comment.

   On error

   Should the backup job continue if this step fails?

   Select ‘continue’ if the job should continue after an error in this step.

   Select ‘abort’ if the job should not continue.

3. Press Accept to save this item.

To define RMAN backup item options

Type

Select 'full' for a level 0 backup.
Select 'differential' for a level 1 backup.

By

Select 'tablespace' to backup the SID where each tblespace will be a backup piece.
Select 'database' to backup the entire SID as one backup piece.

Note - Each backup piece must fit onto a single tape, other wise a new tape will be loaded and the backup of that piece will be attempted again.

Control file?

Check 'yes' to backup the control file after backing up the database or tablespaces.

Spfile?

Check 'yes' to backup the SP file after backing up the database or tablespaces.

Archive logs?

Check 'yes' to backup the archived log files after backing up the database or tablespaces.

Include tablespaces

Only backup these tablespaces in this backup step.

Exclude tablespaces

Do not backup these tablespaces.

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