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  1. 1. Agenda RMAN Architecture  Why Use RMAN?  Implementation Decisions  RMAN Oracle9i New Features 
  2. 2. RMAN Architecture   Recovery Manager (RMAN) is a tool that can be used for Backup, Restore, and Recovery operations on your target database Standard utility when installing Oracle binaries • No extra license required • Only works on 8.0 or higher • Some features only implemented if using Enterprise Edition
  3. 3. RMAN Architecture (continued) Target Database datafiles controlfiles Archived redo logs Server Processes rman Server Processes Server Processes Backup files on disk Recovery Catalog Database (optional) Media Management (optional) Backup media
  4. 4. RMAN Architecture (continued)  Target Database • Database to be backed up, restored,or recovered • Datafiles, controlfies, archived redo files are backed up  rman executable • Utility you invoke for backup, restore, and recovery operations  Processes and Channels • RMAN uses processes to communicate with target and catalog databases • A process opened for I/O is called a channel
  5. 5. RMAN Architecture (continued)  Backups, Backup Sets, Backup Pieces • • • •  Backups are made up of Backup Sets Backup Sets are made up of Backup Pieces Backup pieces are the physical backup files rman is only utility that can read/write from physical files Target database control files • Contain information about RMAN backup operations • SQL> alter session set events „immediate trace name controlf level 10‟;  Backup sets, pieces, datafiles  Configuration settings (Oracle9i only)
  6. 6. RMAN Architecture (continued)  What‟s the Catalog Database? • A separate database usually on a separate host from target database • Schema that has objects that store data about backup, restore, and recovery activities  Catalog Database (optional) • Optional because much of same meta data in catalog is always stored in the target control file  Catalog does not contain backup files
  7. 7. RMAN Architecture (continued)  Media Management Layer (MML) • • • • • 3rd party piece of software Tracks what files have been written to what tapes MML required if backing up files to tape Optional because you can take backup directly to disk Can be frustrating to setup
  8. 8. So Why Use RMAN?  Incremental backups • Full will backup only used blocks • Incremental scheme to back up changed blocks • Backup resources correlate to transaction activity and not the size of the database
  9. 9. RMAN Advantages (continued)  Tablespaces not put in backup mode • No extra logging of full blocks to online redo logs during backup • With RMAN a database process is doing the copy • RMAN does a head/tail check on each block
  10. 10. RMAN Advantages (continued)  Automatic checking for corruption • Database block • Archived redo log RMAN reads every block and checks for corruption  Corrupt blocks information logged  • v$backup_corruption • v$copy_corruption
  11. 11. RMAN Advantages (continued)  Configurable I/O characteristics • • • Configure multiple I/O channels to process in parallel backup and restore commands Set max file size Set max read rate
  12. 12. RMAN Advantages (continued)  Logging of all backup operations • • RMAN writes what/when/where to target controlfile (and catalog if using) Listing and reporting commands
  13. 13. Implementation Decisions     Backup to disk (no MML required) Backup to tape (must use MML) Use RMAN with catalog Use RMAN without catalog
  14. 14. Most Moving Parts Target Database datafiles controlfiles Archived redo logs Server Processes rman Server Processes Server Processes Recovery Catalog Database MML Backup media
  15. 15. Simplest Implementation Target Database datafiles controlfiles Archived redo logs rman Server Processes Server Processes Backup files on disk
  16. 16. Disk Based Backup Set channel type disk  Let O/S backup scrape files to tape  Sometime after O/S backup delete RMAN backup files from disk  Advantages of Disk  • Easier to setup (no MML) • Fewer moving parts • Disk access faster
  17. 17. Disk Based Backup (continued)  Disadvantages of Disk • If RMAN backup file has been deleted from disk, and if needed during a restore, DBA has to tell Operator which file needs to be retrieved and what day it was backed up
  18. 18. Tape Based Backup  Configure RMAN to backup to tape • Implement MML • Set channel type sbt_tape  Advantages of Tape • Tape storage is cheaper than disk • Might be only option for a large database • MML keeps track of long history of what file is on what tape
  19. 19. Tape Based Backup (continued)  Disadvantages of Tape • • MML setup can be frustrating And MML adds complexity
  20. 20. Why Use a Catalog?  Gives you more flexibility in certain situations  Oracle8i reasons to use a catalog •Restoring controlfile •Marking backup sets unavailable •Listing commands
  21. 21. Why Use a Catalog? (continued)  8i and 9i Reasons to Use Catalog •  If not using catalog, finite amount of days of RMAN backup operations stored • •  One centralized repository for all your target databases control_file_record_keep_time has a default of 7 days Could be an issue for a database with hundreds of datafiles With catalog you can store data for long periods of time
  22. 22. Catalog Disadvantages Another moving part  Another database to maintain, monitor, backup, etc.  Can get complex if many different versions of targets  • One catalog, one schema • One catalog, multiple schemas • Different catalogs
  23. 23. If Not Using a Catalog May need to increase init.ora control_file_record_keep_time  In 8i, ensure that you backup your controlfile outside of RMAN  SQL> alter database backup controlfile to „<path>/<filename>‟;
  24. 24. RMAN 9i New Features RESTORE command optimized  Block level recovery  New ways to handle archived redo  Configurable Persistent Settings  •Autobackup of controlfile •Optimization •I/O channel characteristics  Backup/Restore syntax simplified
  25. 25. Oracle9i New Features  Can easily give fellow DBA heart attack •  Pick a paranoid one Setup • • • No Server Manager in Oracle9i Create a file $ORACLE_HOME/bin/svrmgrl chmod +x echo “ “ echo “SVRMGR> ORA-99999: deleting all datafiles…” sleep 2
  26. 26. RMAN 9i New Features  RESTORE command optimized  RMAN restore now does: • Checks if file is on disk • Checks file header • If passes checks, does not restore  Can override w/FORCE option
  27. 27. RMAN 9i New Features Block Level Recovery  Detecting block level corruption  •v$backup_corruption •trace files •dbverify RMAN> blockrecover datafile 2 block 30;
  28. 28. RMAN 9i New Features  Block Level Recovery (continued) • • • • Appropriate for small amounts of corruption Could reduce mean time to recovery Does not replace datafile restore/recovery Gives DBA another restore/recovery tool
  29. 29. RMAN 9i Archive Redo Backups  New BACKUP … PLUS ARCHIVELOG command RMAN> backup database plus archivelog; 1. 2. 3. 4. 5. Switches online redo logs Backup archivelog all; Backs up files database datafiles Switches online redo logs Backs up any archived redo logs generated during backup
  30. 30. 9i RMAN Controlfile Restore    New CONFIGURE command Settings stored in target controlfile Enable autobackup controlfile RMAN> configure controlfile autobackup on;   Controlfile automatically backed up with BACKUP and COPY commands RMAN controlfile restore can then be done without connecting to catalog
  31. 31. RMAN 9i New Features (continued)  Configure optimization RMAN> configure backup optimization on;  If a file has been backed up and hasn‟t changed since last backup, RMAN will skip the file
  32. 32. RMAN 9i New Features (continued) Configure persistent channel I/O settings  Persist until you change or clear  RMAN> configure default device type to disk; RMAN> configure device type disk parallelism 2; RMAN> configure channel device type disk format /ora01/brdstn/rman_%U.bus; RMAN> show all;
  33. 33. RMAN 9i New Features (continued) Syntax simplified for BACKUP and RESTORE commands  No longer required to wrap within RUN{} command  Syntax now can be as simple as:  RMAN> backup database; RMAN> restore database;
  34. 34. RMAN Summary RMAN has significant advantages  Many different ways to implement  Enhancements to RMAN in Oracle9i  Q&A 