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Learn to create backup sets, manage backups, and issue Recovery Manager commands effectively with examples. Explore the types of RMAN commands and necessary constraints for backup operations.
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Commands BACKUP Block C.T. Inc. Update LIST REPORT DELETE Objectives • After completing this lesson, you should be able to do the following: • Use the RMAN BACKUP command to create backup sets and image copies • Manage the backups and image copies taken with RMAN
Issuing Recovery Manager Commands • Interactive client • Enter commands at RMAN prompt. • Use when performing analysis, or when running reports or stored scripts. • Batch mode • Use with automated jobs. • Specify a command file when starting RMAN. • Specify the log file name to capture session log. • Pipe interface • Specify the PIPE command-line argument. • Use to communicate data between sessions or between RMAN and an external application.
Types of RMAN Commands • RMAN commands are of the following types: • Stand-alone command: • Is executed individually at the RMAN prompt • Cannot appear as subcommands within RUN • Job command: • Must be within the braces of a RUN command • Is executed as a group • Some commands can be executed as either astand-alone or a job command.
Job Commands: Example • Job commands appear inside a RUN command block: RMAN>RUN { 2>BACKUP AS BACKUPSET 3>FORMAT '/u01/db01/backup/%d_%s_%p' 4> DURATION 10:00 MINIMIZE LOAD 5>(DATABASE); 6>SQL'alter system archive log current'; 7>}
Enterprise Manager Storedscripts Catalog database RMAN Commands: Overview RESTORE RECOVER FLASHBACK RMAN BACKUP SPFILE REPORT LIST Targetdatabase Controlfile Catalog maintenanceCROSSCHECK DELETE…EXPIRED CHANGE Archivedlog files
Data file 1 Data file 3 Data file 2 Data file 3 Commands > BACKUP Block C.T. Inc. Update LIST REPORT DELETE BACKUP Command RMAN> BACKUP AS BACKUPSET 2> FORMAT '/BACKUP/df_%d_%s_%p.bus' 3> TABLESPACE hr_data; Backupset Data file 1 Data file 2 Tablespace HR_DATA
Backup Constraints • The database must be mounted or open. • You cannot back up online redo logs. • Only “clean” backups are usable in NOARCHIVELOG mode. • Only “current” data file backups are usable in ARCHIVELOG mode.
Channel Channel Data file 1 Data file 4 Data file 5 Backuppiece 2 MML MML Data file 2 Data file 3 Data file 9 Data file 6 Data file 7 Data file 8 Parallelization of Backup Sets • For performance, allocate multiple channels and assign files to specific channels. Backuppiece 1 Channel BackupPiece 3 MML
Compressed Backups RMAN> BACKUP AS 2> COMPRESSED BACKUPSET 3> DATABASE; Compressed backup files Database files RMAN> CONFIGURE DEVICE TYPE 2> DISK PARALLELISM 2 3> BACKUP TYPE TO 4> COMPRESSED BACKUPSET;
Image Copy RMAN> BACKUP AS COPY 2> DATAFILE '/ORADATA/users_01_db01.dbf' 3> FORMAT '/BACKUP/users01.dbf';RMAN> BACKUP AS COPY 4> ARCHIVELOG LIKE 'arch_1060.arc' 5> FORMAT 'arch_1060.bak'; Copy of data file 3 Data file 3 Data file 3 Copy of archived log Archivedlog file Archivedlog file
Tags for Backups and Image Copies • A tag is a logical name assigned to a backup set or image copy. month_full_backup week_full_backup Data files 1,3 Data file 3 Data files 2,4 Data file 4 Backup set Backup set
BACKUP Command Options • Check for physical block corruptions. • Scan for logical corruptions and physical corruptions. • Set a threshold on the number of detected corruptions allowed before aborting. • Validate the target input files before performing a backup operation. • Duplex the backup set. • Overwrite an existing backup set or image copy. • Pass control of the data transfer between storage devices and the data files on disk to the media management layer. • Encrypt the backup files.
Backing Up Archived Redo Logs • Online redo log file switch is automatic. • Archived log failover is performed. • You can specify a range of archived redo logs to back up. • Backup sets of archived redo log files cannot contain any other type of file. RMAN> BACKUP 2> FORMAT '/disk1/backup/ar_%t_%s_%p' 3> ARCHIVELOG FROM SEQUENCE=234 4> DELETE INPUT;
Whole Database Backup RMAN>BACKUP DATABASE PLUS ARCHIVELOG; Controlfile Archived log file copies Data file copies SPFILE
RMAN Backup Types Full, or "level 0incremental backup" • A full backup contains all used data file blocks. • A level 0 incremental backup is equivalent to a full backup that has been marked as level 0. • A cumulative level 1 incremental backup contains only blocks modified since thelast level 0 incremental backup. • A differential level 1 incremental backup contains only blocks modified since the last incremental backup. Cumulative incremental backup Differential incremental backup
Differential Versus Cumulative • A differential incremental backup contains all blocks changed since the last incremental backup. • A cumulative incremental backup contains all blocks changed since the last level 0 incremental backup. Level 0 Level 0 0 1 1 1c 1 1c 1 0 Lvl Day Sun Mon Tue Wed Thu Fri Sat Sun
Commands BACKUP > Block C.T. Inc. Update LIST REPORT DELETE Block Change Tracking • The backup process can be streamlined by enabling block change tracking, which: • Records changed blocks in a change tracking file • Is used automatically by RMAN, if enabled • Optimizes incremental backups by avoiding full data file scans during backup List of changed blocks 1011001010110 0001110100101 1010101110011 Change trackingfile CTWR Redogeneration SGA Redo log
Enabling Block Change Tracking SQL> ALTER DATABASE ENABLE 2> BLOCK CHANGE TRACKING 3> USING FILE '/mydir/rman_change_track.f' 4> REUSE;
Commands BACKUP Block C.T. > Inc. Update LIST REPORT DELETE Incrementally UpdatingBackups Image copyof data file Incremental backup files RMAN> RECOVER COPY OF 2> DATAFILE {n|'file_name'} 3> WITH TAG 'incr_upd_df1'; Image copy of data file updated to a more recent state Recovered data file
Commands BACKUP Block C.T. Inc. Update > LIST REPORT DELETE LIST Command • List backup sets and copies of data files: • List backup sets and copies of any data file for a specified tablespace: • List backup sets and copies containing archive logs for a specified range: RMAN> LIST BACKUP OF DATABASE; RMAN> LIST BACKUP OF DATAFILE 2> "/db01/ORADATA/u03/users01.dbf"; RMAN> LIST COPY OF TABLESPACE "SYSTEM"; RMAN> LIST COPY OF DATABASE ARCHIVELOG 2> FROM TIME='SYSDATE-7';
REPORT Command Commands BACKUP Block C.T. Inc. Update LIST > REPORT DELETE • Produces a detailed analysis of the repository • Produces reports to answer: • What are the data files in the database? • Which files need a backup? • Which backups can be deleted? • Which files are unrecoverable?
REPORTNEEDBACKUP Command • Lists all data files that require a backup • Assumes that the most recent backup is used during a restore • Provides four options: • Incremental • Days • Redundancy • Recovery window • Uses the current retention policy configuration if no options are specified
REPORTNEEDBACKUP: Examples • Files that need more than three incremental backups for recovery: • Files that have not been backed up for three days: • Backup needed if there are not two or more backups already: • Backup needed to recover to three days ago: RMAN> REPORT NEED BACKUP incremental 3; RMAN> REPORT NEED BACKUP days 3; RMAN> REPORT NEED BACKUP redundancy 2; RMAN> REPORT NEED BACKUP 2> recovery window of 3 days;
Commands BACKUP Block C.T. Inc. Update LIST REPORT > DELETE REPORTOBSOLETE andDELETEOBSOLETE • Find all recovery files that are deemed obsolete according to the current retention policy settings: • List the obsolete recovery files, if no more than two backup copies are needed: • Delete the backup set with a backup set key of 4: • Delete the recovery files considered obsolete, because they have more than two backups: RMAN> REPORT OBSOLETE; RMAN> REPORT OBSOLETE REDUNDANCY 2; RMAN> DELETE BACKUPSET 4; RMAN> DELETE OBSOLETE REDUNDANCY 2;
Managing Backups with EM Navigation aid:Database home page > Maintenance > Manage Current Backups
RMAN Dynamic Views • V$ARCHIVED_LOG • V$BACKUP_CORRUPTION • V$BACKUP_DEVICE • V$BACKUP_FILES • V$BACKUP_PIECE • V$BACKUP_REDOLOG • V$BACKUP_SET • V$BACKUP_SPFILE • V$COPY_CORRUPTION • V$RMAN_CONFIGURATION
Monitoring RMAN Backups • Correlate server sessions with channels by using the SETCOMMANDID command. • Query V$PROCESS and V$SESSION to determine which sessions correspond to which RMAN channels. • Query V$SESSION_LONGOPS to monitor the progress of backups and copies. • Use an operating system utility to monitor the process or threads.
Summary • In this lesson, you should have learned how to: • Use the RMAN BACKUP command to create backup sets and image copies • List backups and image copies taken with RMAN • Report and delete obsolete RMAN backups
Practice Overview: Backing UpYour Database • This practice covers the following topics: • Enabling archival of redo logs for a database • Using RMAN to display the database structure • Using Recovery Manager to back up data files and the control file • Using Recovery Manager to make image copies of data files • Creating a compressed backup of a database • Scheduling a backup job