RMAN Basic Commands
8 min readOracle Recovery Manager (RMAN) satisfies the most pressing demands of performance, manageable backup and recovery, for all Oracle data formats.
RMAN provides a common interface, via command line and Enterprise Manager, for backup tasks across different host operating systems.
The RMAN command for making backups is Backup. The RMAN BACKUP command supports backing up the following types of files:
- Datafiles and control files
- Server parameter file
- Archived redo logs
- RMAN backups
When you execute the BACKUP command in RMAN, the output is always either one or more backup sets or one or more image copies. A backup set is an RMAN-specific proprietary format, whereas an image copy is a bit-for-bit copy of a file. By default, RMAN creates backup sets.
Below are some of the commonly used RMAN commands which you can run through RMAN command line.
1) Shows all parameters. RMAN> show all; 2) Shows the archivelog deletion policy. RMAN> show archivelog deletion policy; 3) Shows the number of archivelog backup copies RMAN> show archivelog backup copies; 4) Shows the auxiliary database information. RMAN> show auxname; 5) Shows whether optimization is on or off. RMAN> show backup optimization; 6) Shows how the normal channel and auxiliary channel are configured. RMAN> show [auxiliary] channel; 7) Shows the characteristics of the channel RMAN> show channel for device type [disk | <media device>; 8) Shows whether control file autobackup is on or off. RMAN> show controlfile autobackup; 9) Shows the format of the autobackup control file RMAN> show controlfile autobackup format; 10) Shows the number of datafile backup copies being kept. RMAN> show datafile backup copies; 11) Shows the default type (disk or tape) RMAN> show default device type; 12) Shows policy for datafile and control file backups and copies that RMAN marks as obsolete. RMAN> show retention policy; 13) Shows the encryption algorithm currently in use. RMAN> show encryption algorithm; 14) Shows the encryption for the database and every tablespace. RMAN> show encryption for [database | tablespace]; 15) Shows the tablespaces excluded from the backup. RMAN> show exclude; 16) Shows the maximum size for backup sets. The default is unlimited. RMAN> show maxsetsize; 17) Shows the policy for datafile and control file backups and copies that RMAN marks as obsolete. RMAN> show retention policy; 18) Shows the snapshot control filename. RMAN> show snapshot controlfile name; 19) Shows the compression algorithm in force. The default is the ZLIB algorithm. RMAN> show compression algorithm;
**BACKUP COMMAND**
1) To perform a manual backup of the current control file RMAN> backup current controlfile; 2) To back up the control file as part of a tablespace backup operation RMAN> backup tablespace users include current controlfile; 3) To back up the server parameter file RMAN> backup spfile; 4) To restart an RMAN backup that failed midway through a nightly backup. RMAN> backup not backed up since time 'sysdate-1' database plus archivelog; 5) To force RMAN to back up a file regardless of whether it’s identical to a previously backed up file by specifying the force option RMAN> backup database force; By using the force option, you make RMAN back up all the specified files, even if the backup optimization feature is turned on. 6) To backup complete database RMAN> backup database; 7) To backup database plus archivelogs RMAN> backup database plus archivelogs; 8) To backup all archive logs RMAN> backup archivelog all; 9) To backup specific data file. A tag was also added to easily locate this datafile’s backup. RMAN> backup datafile 5 tag dbfile_5_bkp;
**CATALOG COMMAND**
1) Add user-managed copies of datafile to RMAN repository RMAN> catalog datafilecopy '/u01/oracle/users.bkp'; RMAN> catalog datafilecopy '/u01/oracle/users.bkp' level 0; (To catalog as incremental level 0 backup) 2) Add uncataloged backup piece to RMAN repository RMAN> catalog backuppiece 'rhsytsv091'; 3) To catalog multiple files ( say you copied production backup to target database for database cloning) RMAN> catalog start with '/backups/source_bkp' noprompt; The start with clause specifies that RMAN catalog all valid backup sets, datafile copies, and archived redo logs starting with the string pattern you pass. 4) To catalog all files in the flash recovery area RMAN> catalog recovery area;
**REPORT COMMAND**
1) To find out which backups you need to make in order to conform to the retention policy you put in place RMAN> report need backup; 2) To get a report about all the datafiles in a database RMAN> report schema; RMAN> report schema at time 'sysdate-1'; (from a past point in time) 3) To reports on any obsolete backups RMAN> crosscheck backup; RMAN> report obsolete; Always run the crosscheck command first in order to update the status of the backups in the RMAN repository to that on disk and tape.
**LIST COMMAND**
1) To review RMAN backups of datafiles, archived redo logs, and control files. RMAN> list backup; 2) List the backups by just the backup files RMAN> list backup by file; 3) Lists only backup sets and proxy copies but not image copies RMAN> list backupset; 4) Lists only datafile, archived redo log, and control file copies RMAN> list copy; 5) Lists backups by tag: RMAN> list backupset tag 'full_database_backup'; 6) To list the backups of all datafiles and archivelogs of the target database: RMAN> list backup of database; 7) Lists all incarnations of a database RMAN> list incarnation; When you perform an open resetlogs operation, it results in the creation of a new incarnation of the database. When performing recovery operations on such a database, you might want to check the database incarnation 8) Lists all restore points in the target database RMAN> list restore point; 9) Lists the names of all recovery catalog scripts RMAN> list script names; 10) Which of the backups of the target database have an expired status in the repository. RMAN> list expired backup; 11) Which of the archived redo log backups have the expired status RMAN> list expired archivelog all; 12) To restrict the list of backups and copies whose status is listed as available RMAN> list recoverable backup; 13) To view all the restore points in the database RMAN> list restore point all;
**CROSSCHECK COMMAND**
1) Cross-checking just backup sets RMAN> crosscheck backupset; 2) Cross-checking a copy of a database RMAN> crosscheck copy of database; 3) Cross-checking specific backupsets RMAN> crosscheck backupset 10, 12; 4) Cross-checking using a backup tag RMAN> crosscheck backuppiece tag = 'monthly_backup'; 5) Cross-checking a control file copy; RMAN> crosscheck controlfilecopy '/backups/control01.ctl'; 6) Cross-checking backups completed after a specific time RMAN> crosscheck backup of datafile "/u01/oracle/system01.dbf" completed after 'sysdate-7'; 7) Cross-checking of all archivelogs and the spfile RMAN> crosscheck backup of archivelog all spfile; 8) Cross-checking all backups on disk and tape RMAN> crosscheck backup; The crosscheck command checks whether the backups still exist. The command checks backup sets, proxy copies, and image copies.
**DELETE COMMAND**
1) To remove both archived redo logs and RMAN backups RMAN> delete backup; RMAN always prompts you for confirmation before going ahead and deleting the backup files. You can issue the delete noprompt command to suppress the confirmation prompt. This will also remove the physical file from the backup media To make sure the repository and the physical media are synchronized, run “RMAN> crosscheck backup;” before running above command 2) To remove all image copies RMAN> delete copy; To make sure the repository and the physical media are synchronized, run “RMAN> crosscheck copy;” before running above command 3) To delete specfic backuppiece RMAN> delete backuppiece 9; 4) To delete copy of controlfile under /backups RMAN> delete copy of controlfile like '/backups/%'; 5) To delete backups with specific tag RMAN> delete backup tag='double_bkp_prod'; 6) To delete bakups of specific tablespace RMAN> delete backup of tablespace sysaux device type sbt; ****************** You can also use force, expired, obsolete keyword with delete commad: delete force ..: Deletes the specified files whether they actually exist on media or not and removes their records from the RMAN repository as well delete expired ..: Deletes only those files marked as expired as per crosscheck command. delete obsolete ..: Deletes datafile backups and copies and the archived redo logs and log backups that are recorded as obsolete in the RMAN repository The delete obsolete command relies only on the backup retention policy in force. ****************** 7) To delete all archived redo logs RMAN> delete archivelog all; 8) To delete already backed up archived redo logs RMAN> delete archivelog all backed up 2 times to sbt; 9) To delete specific archived redo logs RMAN> delete archivelog until sequence = 1234; 10) Delete archive logs after taking backup RMAN> backup device type sbt archivelog all delete all input; 11) Delete stored script RMAN> delete script full_disk_db; If you have two scripts—one local and one global—in the same name, then the delete script command drops the local one, not the global one. If you want to drop the global script, you must use the keyword global in the command, as shown here: RMAN> delete global script full_disk_db;
**CHANGE COMMAND**
1) Change the status of a backup set to unavailable RMAN> change backupset 6 unavailable; You usually do it when you don’t want to delete the backup/copy but you also don’t want to delete that backup/copy (probably it is not available physically on disk) Once you mark a backup file unavailable, RMAN won’t use that file in a restore or recover operation. 2) Change the status of a backup set to available again RMAN> change backupset 6 available; For example, say you performed a backup using an NFS-mounted disk and that disk subsequently becomes inaccessible for some reasons, just issue the change command to set the status of the backup as unavailable. Later, once the disk becomes accessible again, you can change its status back to available. 3) To modify a regular consistent database backup into an archival backup: RMAN> change backup tag 'initial_db_bkup' keep forever; When you make an archival backup with the keep … forever option, RMAN disregards the backup retention time for these backups. 4) To change the archival backup to a normal database backup RMAN> change backup tag 'inital_db_backup' nokeep; When you run the change … nokeep command, the backup set with the tag inital_db_backup, which was previously designated as a long term archival backup, will once again come under the purview of your configured retention policy. 5) To modify the time period for which you want to retain the archival backups RMAN> change backupset 12 keep until time 'sysdate+60'; After the 60 days are up, the backup will become obsolete and is eligible for deletion by the delete obsolete command.
**VALIDATE COMMAND**
1) To check all the datafiles and the archived redo logs for physical corruption without actually performing the backup RMAN> backup validate database archivelog all; 2) To check for logical corruption without actually performing the backup RMAN> backup validate check logical database archivelog all; The check logical clause means that RMAN will check for logical corruption only. 3) To validate a single backup set RMAN> validate backupset 5; 4) To validate all datafiles at once RMAN> validate database; Note that the validate command can check at a much more granular level than the backup … validate command. You can use the validate command with individual datafiles, backup sets, and even data blocks. he validate command always skips all the data blocks that were never used, in each of the datafile it validates. 5) To validate recovery area RMAN> validate recovery area; 6) To validate all the recovery related files RMAN> validate recovery files; 7) To validate the spfile RMAN> validate spfile; 8) To validate specific tablespace RMAN> validate tablespace <tablespace_name>; 9) To validate specific control file copy RMAN> validate controlfilecopy <filename>; 10) To validate specific backupset RMAN> validate backupset <primary_key>;
Very useful commands in one go. Love the presentation.