•Scheduled RMAN backup jobs do not run. If you change the database mode to no archive during an RMAN backup, the RMAN backup will error out.

•If the database fails as a result of a corrupt data file, the database can only be restored to the last export backup available. This requires recreating the database along with the import.

When you change the database to archive mode, you reset the logs SCN, set the archive parameter in the database parameter file and enable the RMAN backup scheduler. Take a current RMAN backup after switching to archive mode, as described in ”Performing an RMAN Hot Backup” on page 204.

Architectural Overview of RMAN Backups

By default the management server does not backup the database automatically. If you enabled the database archive mode and RMAN backup as described in ”Setting the Archive Mode” on page 212, the management server backs up the Oracle instance for the management server every three days and saves the backup for two weeks. The management server alternates the directories in which it saves the backup. When the management server first performs a scheduled backup, the backup is saved in %ORA_HOME%\rman\backup1. The next time the management server performs a scheduled backup, it is saved %ORA_HOME%\rman\backup2. The management server saves the backup in alternating directories (backup1 and backup2), so you always have a copy of the last backup and the previous backup. To learn how to change the frequency of the scheduled backups, see ”Scheduling RMAN Hot Backups of the Database” on page 204.

You can back up the database at any time by clicking the Backup Now button on the Database tab. When you back up the database using this technique, the backup is saved only in %ORA_HOME%\rman\current. To recover the database, contact customer support.

Table 25 Backup Directories in %ORA_HOME%\rman

Directory

Contains

 

 

current

The backup when the Database Server Backup

 

button was clicked.

 

 

log

A log of when the backup was done.

backup1

Information from the automatic backup (alternating

 

day).

 

 

backup2

Information from the automatic backup (alternating

 

day).

Let's assume you recently installed the management server and you have not done any backups. You have schedule the backups to take place every three days. You performed a backup, and it is stored in the backup1 folder. The next scheduled backup occurs on day 4 and it is saved in the backup2 folder. If your database fails, you can restore the database from day 1 or day 4. Let's assume you have a scheduled backup on day 7, which is saved to the backup1 folder. This backup replaces the backup from day 1. The available backups are from day 4 and 7. Assume you click the

202 Database Maintenance and Management