The following one-time configuration specifies that archived redo logs are eligible for deletion from disk if two archived log backups exist on tape: After running the script in Example 9-2, you can delete unneeded logs by executing DELETE ARCHIVELOG ALL. Offline datafiles. Some offline data files can still be read because they exist on disk. Specify a valid date in the SINCE TIME parameter. You can break up the data file in this tablespace into file sections as shown in the following example: In this example, each of the three SBT channels backs up a 300 MB file section of the users data file. The COPIES option of the BACKUP command overrides every other COPIES or DUPLEX setting to control duplexing of backup sets. Thus, if you retry a job that was interrupted when the available duration expired, each successive attempt covers more of the files needing backup. You are worried about tape failure, however, so you want to ensure that you have more than copy of each log sequence number on an separate tape before you perform your weekly deletion of logs from disk. For example, you can set an upper limit for block reads so that RMAN does not consume excessive disk bandwidth and thereby degrade online performance. Specifying a window does not mean that RMAN backs up data faster than normal in order to ensure that the backup completes before the window ends. Also assume that three SBT channels are configured, with the parallelism setting for the SBT device set to 3. The following example backs up archived logs to tape, limiting the size of each backup set to 100 MB: If you specify the SECTION SIZE parameter on the BACKUP command, then RMAN creates a backup set in which each backup piece contains the blocks from one file section. These separate tablespaces can be backed upwhen the data reaches the point that it will not be changed again, and then it can be excluded from the normal backup routine. If you specify a small section size that would produce more than 256 sections, then RMAN increases the section size to a value that results in exactly 256 sections. Assuming that we have just migrated a non-CDB database to PDB and our pluggable database has 4 tablespaces all open read/write. At the end of the backup, you want to delete all archived logs that already have at least two copies on tape. Oracle Database Backup and Recovery Reference for BACKUP NOT BACKED UP syntax. We have very large tables that contain hundreds of datapoints per sensor. A file section is a contiguous range of blocks in a file. To only back up files that were not backed up after a specified date: Specify a valid date in the SINCE TIME parameter. RMAN attempts to limit all backup sets to this size. You can specify parameters to prevent termination, as listed in Table 9-2. When architecting the database, the age of the data, and therefore the possibility of data changing can be used as a factor in the physical database design that can optimize backup and recovery efficiency and performance. If you specify a section size that is larger than the size of the file, then RMAN does not use multisection backup for the file. If a multisection backup completes successfully, then none of the backup sets generated during the backup contain a partial datafile. |Service For each backup piece that it restores, RMAN checks whether it is encrypted.

In this scenario, you back up logs that are not on tape to one media family, then back up the same logs to a second media family. The procedure in this section explains how to make a split mirror backup with the ALTER SYSTEM SUSPEND/RESUME functionality. If RMAN finds a usable key, then the restore operation proceeds; otherwise, RMAN signals an error that the backup piece cannot be decrypted. If transparent encryption is configured, then omit the ONLY keyword to indicate that the backups are protected with both a password and the configured transparent encryption. You can use BACKUP MAXSETSIZE to limit the size of backup sets so that the database is divided among multiple backup sets. Configuring the Maximum Size of Backup Sets, Configuring the Maximum Size of Backup Pieces. Individual backup encryption keys or passwords are never stored in clear text. These include application performance, business continuity, security, and geographic distribution. Use this feature after a backup fails to back up the parts of the database missed by the failed backup. The database uses a new encryption key for every encrypted backup. All archived logs that have been backed up at least twice to tape are deleted. You can use this command to configure dual mode or password mode encryption at the RMAN session level. For example, you may want to restrict your database backups to a window of time when user activity on your system is low, such as between 2:00 a.m. and 6:00 a.m. RMAN backs up the least recently backed up files first. RMAN displays an error stack such as the following: Backup piece size is an issue in those situations where it exceeds the maximum file size of the file system or media management software. You can protect RMAN backup sets with backup encryption. Make Parallel the Validation of a Data File, About Backup Optimization for SBT Backups with Recovery Window Retention Policy, Maintaining RMAN Backups and RepositoryRecords, About Configuring the Environment for RMAN Backups, Media Manager Component of the Write Phase for SBT. First, perform a one-time configuration as follows: Because you have optimization enabled, you can run the following command every evening to back up all archived logs to the first_copy media family that have not already been backed up: Every Friday evening you create an additional backup of all archived logs in a different media family. You can restart a backup by specifying the SINCE TIME clause on the BACKUP command. For example, run the. Some mirroring technology does not require Oracle Database to suspend all I/O before a mirror can be separated and used as a backup. In many databases, older data represents a very large portion of the overall database, so such a scheme can significantly reduce the backup time, thereby significantly reducing the impact on the application. The COPIES option of the BACKUP command overrides every other COPIES or DUPLEX setting to control duplexing of backup sets. You can break up the datafile in this tablespace into file sections as shown in the following example: In this example, each of the three SBT channels backs up a 300 MB file section of the users datafile. If the BACKUP command is part of a RUN block, then the remaining commands in the RUN block continue to execute.

In Example 9-5, RMAN monitors the progress of the running backup, and periodically estimates how long the backup takes to complete at its present rate. Some mirroring technology does not require Oracle Database to suspend all I/O before a mirror can be separated and used as a backup. Hongmei Neon Equipment Factory If the SINCE TIME is later than the completion time, then RMAN backs up the file. The CONFIGUREBACKUP COPIES command specifies the number of identical backup sets to create on the specified device type. A datafile backup on disk simplifies the restore step of recovery, making recovery much quicker and more reliable. An added benefit is that the backup set each week will be significantly smaller thereby reducing disk requirements for the ongoing backup sets.

Use this tape backup only if the primary tape from pool first_copy is damaged. In a Multitenant environment is more important than ever to understand the effects of the parameterCONFIGURE BACKUP OPTIMIZATION which can be set to ON or OFF. by Robert Buda | Aug 3, 2017 | Backup and Recovery, Best Practices, Database Architecture, Oracle | 0 comments. Huanhua Road With RMAN configured as shown in Example 9-1, you run the following command every night to back up the database to tape: Because backup optimization is configured, RMAN skips backups of offline and read-only datafiles only if the most recent backups were made on or after the earliest point in the recovery window. Any completed backup sets are retained and can be used in restore operations, even if the entire backup is not complete. The minimum unit of restartability is a datafile. You cannot specify SECTION SIZE with MAXPIECESIZE. It is fully integrated with the Multitenant Architecture allowing to implement Manage Many-Databases-as-One strategy. Liwan District, Guangzhou,Guangdong (P.R.China) If you enjoyed this article please like and share! In Oracle Secure Backup, a media family is a named group of volumes with a set of shared, user-defined attributes. Because of these concerns, it is not recommended that you use MINIMIZE LOAD when backing up to tape. If you have configured transparent encryption with the CONFIGURE command as explained in "Configuring RMAN Backup Encryption Modes", then no additional commands are required to create encrypted backups. This prevents the use of the tape resource for any other purpose during the backup window. The MAXSETSIZE parameter of the BACKUP command specifies a maximum size for a backup set in units of bytes (default), kilobytes, megabytes, or gigabytes. As explained in "Configuring Backup Encryption", you can protect RMAN backup sets with backup encryption. Because the secondary tape is offsite, you do not want RMAN to use it for recovery, so you can mark the backup as unavailable: Chapter 11, "Maintaining RMAN Backups and RepositoryRecords" to learn how to change the status of and delete backups, Oracle Database Backup and Recovery Reference to learn about the CHANGE and DELETE commands. Backup piece size is an issue in those situations where it exceeds the maximum file size of the file system or media management software. This chapter contains the following topics: Skipping Offline, Read-Only, and Inaccessible Files. Assume that you want to back up all the archived logs every night, but you do not want to have multiple copies of each log sequence number. COPIES: Specify the number of identical copies with the COPIES option of the BACKUP command. Backup encryption is performed based on the encryption settings specified with the following commands: You can use this command to persistently configure transparent encryption. Restoring online redo log backups can create two archived logs with the same sequence number but different contents. RMAN can back up only those files that have not been backed up since a specified date. The first option, backup up from a standby database, may not be an option of you dont have a high availability environment. For example, run the following to make three copies of each backup set in the default DISK location: Because you specified COPIES in the BACKUP command, RMAN makes three backup sets of each datafile regardless of the CONFIGURE DATAFILE COPIES setting. If RMAN restores a set of backups created with different passwords, then all required passwords must be included with SET DECRYPTION . Use the SINCE TIME parameter of the BACKUP command to specify a date after which a new backup is required. Example 10-3 Skipping Files During an RMAN Backup. |Products If you specify a section size that is larger than the size of the file, then RMAN does not use multisection backup for the file. Resilver the split mirror for the affected data files. Oracle Database Backup and Recovery Reference, "Configuring the Maximum Size of Backup Sets", "Configuring the Maximum Size of Backup Pieces", "Parallelizing the Validation of a Datafile", "Backup Optimization for SBT Backups with Recovery Window Retention Policy", Chapter 11, "Maintaining RMAN Backups and RepositoryRecords", "Configuring the Environment for RMAN Backups", "Configuring RMAN Backup Encryption Modes", "Media Manager Component of Write Phase for SBT". When architecting database, think about what the impact of the backup and RMAN database recovery process will look like after 10 years. For the following scenarios, assume that you configure backup optimization and a retention policy as shown in the following example. RMAN encryption is a CPU intensive operation and can impact backup performance. All archived logs created since the last DELETE command are still on disk. If the SINCE TIME is later than the completion time, then RMAN backs up the file. This section contains the following topics: Limiting the Size of Backup Sets with BACKUP MAXSETSIZE, Dividing the Backup of a Large Data File into Sections. |News The following example sets the encryption password for all tablespaces (where password is a placeholder for the actual password that you enter) in the backup and specifies ONLY to indicate that the encryption is password-only: Use the SET ENCRYPTION BY PASSWORD command at the RMAN prompt to make password-protected backups. Thus, if you retry a job that was interrupted when the available duration expired, each successive attempt covers more of the files needing backup. Transparently encrypted backups need no intervention if the Oracle wallet is open and available. Very large databases are common in todays business environment. A backup window is a period of time during which a backup must complete. Use the MAXSETSIZE parameter of the CONFIGURE CHANNEL or ALLOCATE CHANNEL command to limit the size of backup pieces. For example, enter: Many sites keep a backup of the database stored on disk in case a media failure occurs on the primary database or an incorrect user action requires point-in-time recovery. Any completed backup sets are retained and can be used in restore operations, even if the entire backup is not complete. Archived logs that have fewer than two backups on tape are now in media families first_copy and second_copy. This setting applies to all backup sets except control file autobackups (because the autobackup of a control file always produces one copy) and backup sets when backed up with the BACKUP BACKUPSET command. You should use this tape backup only if the primary tape from pool first_copy is damaged. After the weekly backup, you can send the tape from the media family second_copy to offsite storage. BACKUP COPIES setting is ignored for image copy backups. Refer to your storage manager, volume manager, or file system documentation for information about whether you must suspend I/O from the database instance. You can specify parameters to prevent termination, as listed in Table 10-2. Dispite having a FULL database backup every night, only 1 backup every 8 days will be complete and consistent, because the RMAN backup optimization algorithm will detect the SEED PDB datafiles unchanged and it will skip those files. RMAN must do further checking to determine whether to skip the file, however, because both the retention policy and the backup duplexing feature are factors in the algorithm that determines whether RMAN has sufficient backups on the specified device type. Such parameters define for example the backup retention policy, the default device type, how many archivelog copy should be stored, if the backup-sets should be compressed and/or encrypted and so on. If the BACKUP command is in a RUN command, then the RUN command terminates.

Example 10-4 Using MINIMIZE TIME with BACKUP DURATION. And there are many databases that are so large that the time it takes to back up the entire database is simply too long and exceeds the non-peak times for the application. Example 9-1 Configuring Backup Optimization. The following example uses the default configured channel to back up all database files and archived redo logs that have not been backed up in the last two weeks: Oracle Database Backup and Recovery Reference for an example of how to use the BACKUP command to restart a backup that did not complete. This control is helpful when backing up very large files. Also assume that three SBT channels are configured, with the parallelism setting for the SBT device set to 3. For example, enter the following command in RMAN: Split the mirrors for the underlying datafiles contained in these tablespaces. You must use the DELETE command to delete the partial backup set. To extend the backup to use the full time available, use the MINIMIZE LOAD option, as in Example 10-5. Thus, to limit a backup set to 305 MB, specify MAXSETSIZE 305M. When backing up to tape, ensure that the number of copies does not exceed the number of available tape devices. Encrypted backups cannot be read if they are obtained by unauthorized users. When backing up to tape, ensure that the number of copies does not exceed the number of available tape devices. First, perform a one-time configuration as follows: Because you have optimization enabled, you can run the following command every evening to back up all archived logs to the first_copy media family that have not already been backed up: Every Friday evening you create an additional backup of all archived logs in a different media family. To make a split mirror backup of a tablespace by using SUSPEND/RESUME: For example, to place tablespace users in backup mode, you connect RMAN to a target database and run the following SQL command: You can also use ALTER DATABASE END BACKUP to take all tablespaces out of backup mode.

RMAN divides the work among multiple channels, with each channel backing up one file section in a file.

Architecting the backup and restore efficiency into the database design at that time will save lots of redesign later on. The following example backs up archived logs to tape, limiting the size of each backup set to 100 MB: If you specify the SECTION SIZE parameter on the BACKUP command, then RMAN creates a backup set in which each backup piece contains the blocks from one file section. This control is especially useful when you use a media manager that has restrictions on the sizes of files, or when you must back up very large files. About Multiple Copies of RMAN Backups for a conceptual overview of RMAN backup copies. Some offline datafiles can still be read because they exist on disk. See Oracle Database Security Guide for more information. It is not possible to duplex backup sets to the fast recovery area. Making the tablespaces readonly, and configuring Backup Optimization in Oracle RMAN. If you do not have a backup set size persistently configured, then you can also use the BACKUP MAXSETSIZE command to limit the size of backup sets. Any incomplete backup sets are discarded.