You can back up the database files and offline redo log files of your Oracle database with BR*Tools. If you are performing an offline backup of the whole database, the temporary files and online redo log files are also backed up. If you have lost data and want to recover it, the backup files are essential. You can also make a database copy and back up non-database files and directories.
You typically use BR*Tools for a one-off backup of the:
· Database files, such as after a structure change to the database. For example, after moving a data file, you can back up the database to make the recovery procedure easier.
· Offline redo log files. Oracle copies the online redo log files to the archiving directory, so creating the offline redo log files.
For routine backups, we recommend one of the following:
· DBA Planning Calendar to schedule a backup and then view its log
· A scheduler offered by a supplier of the BACKINT interface
· The scheduler cron for UNIX or at for Windows
If you need to recover your database, you must have access to all offline redo log files that have been written since the database backup. Otherwise you can only recover the database to the point in time of the last available redo log. Therefore, you must always back up the offline redo log files after a database backup, and immediately after an online backup.
In production systems, we strongly recommend you to:
· Run the database in ARCHIVELOG mode with automatic archival turned on. For more information, see Setting Up Archiving.
· Make two copies of the offline redo log files. In test systems, one copy is often sufficient.
· BRTOOLS normally calls the SAP tool BRBACKUP or BRARCHIVE to perform the backup. You can also perform a backup directly by calling BRBACKUP or BRARCHIVE from the command line.
We recommend you to normally use BRTOOLS rather than BRBACKUP or BRARCHIVE. This is because the BRTOOLS menus simplify entry of the correct parameters.
· “Archiver stuck” problem
The Oracle database hangs if it is operated in ARCHIVELOG mode, but the archiving process cannot save the online redo log files because the archiving directory is full. This situation is called “archiver stuck.” If this occurs you must back up the offline redo log files and delete them from the archive directory as soon as possible.
To avoid archiver stuck, back up the offline redo log files regularly to tape. How often you do this depends on the amount of activity in your SAP System. If a lot of redo log entries are written, and the redo log files are frequently switched, be sure to constantly monitor the archive directory. When necessary, save and delete the offline redo log files.
For more information about avoiding "archiver stuck," see SAP Note 316642.
· Make sure the necessary parameters have been set for BRBACKUP and BRARCHIVE in the Initialization Profile init<DBSID>.sap.
· You can back up the offline redo log files regardless of the current status of the database (open or closed) and the SAP system. If you have configured your system according to the SAP recommendations, the Oracle database system saves the online redo log files automatically as offline redo log files. Unless you have changed the standard profile init<DBSID>.ora, the offline redo log files are stored in the archive directory <SAPDATA_HOME>/oraarch. For more information, see Setting Up Archiving.
You can perform the following backup functions with BR*Tools:
· Database backup
· Archivelog backup (that is, backup of the offline redo log files)
· Database copy
· Non-database backup
· Backup of database disk backup
· Verification of database backup
· Verification of archivelog backup
· Additional functions
Ў Update of compression rates
Ў Preparation of RMAN backups
Ў Deletion of database disk backups
Ў Deletion of archivelog disk backups
Ў Controlling of BRARCHIVE run
Ў Initialization of BRBACKUP tape volumes
Ў Initialization of BRARCHIVE tape volumes
BRTOOLS calls BRRESTORE for the verification functions.
1. You call the backup function in BRTOOLS and check the displayed backup parameters, changing them as required.
The default parameter values, which are set in the initialization profile init<DBSID>.sap, are as follows:
Ў For database backup, the default is an offline whole database backup to a local tape device without file compression. This means that the online redo log files and control file are backed up as well as the data files.
Ў For archivelog (that is, offline redo log) file backup, the default is a first copy backup of offline redo log files without deletion to a local tape device without file compression.
BRTOOLS only lets you change certain parameters for the backup. If you have to make other changes, you must change the init<DBSID>.sap profile manually and then restart BRTOOLS.
2. If required, you change the default values for the backup parameters in the initialization profile init<DBSID>.sap and restart BRTOOLS.
3. If required, you choose Backup and Database Copy ® Reset program status to set the defaults used to the values in the initialization profile init<DBSID>.sap. For certain input values, there is no corresponding parameter in the initialization profile, in which case the default value from the BRTOOLS program is used.
4. You start the backup.
If the backup is being made locally or remotely to tapes or disks, then the backup is monitored and an estimation is made of the backup time, based on the elapsed time and the size of the files that still have to be backed up. You also see success or error messages.