1. Agenda
RMAN Architecture
 Why Use RMAN?
 Implementation Decisions
 RMAN Oracle9i New Features


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. 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. 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. 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. 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. 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. 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. 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. 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. 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. 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. Implementation Decisions




Backup to disk (no MML required)
Backup to tape (must use MML)
Use RMAN with catalog
Use RMAN without catalog

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. Simplest Implementation
Target
Database
datafiles
controlfiles
Archived
redo logs
rman
Server
Processes
Server
Processes
Backup files
on disk

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. 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. 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. Tape Based Backup
(continued)

Disadvantages of Tape
•
•
MML setup can be frustrating
And MML adds complexity

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. 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. 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. 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. 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. 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. 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. RMAN 9i New Features
Block Level Recovery
 Detecting block level corruption

•v$backup_corruption
•trace files
•dbverify
RMAN> blockrecover datafile 2 block 30;

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. 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. 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. 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. 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. 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. RMAN Summary
RMAN has significant advantages
 Many different ways to implement
 Enhancements to RMAN in Oracle9i
 Q&A
