PPOUG, 05-OCT-01 Agenda RMAN Architecture Why Use RMAN? Implementation Decisions RMAN Oracle9i New Features

PPOUG, 05-OCT-01 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

PPOUG, 05-OCT-01 RMAN Architecture (continued) Target Database datafiles controlfiles Archived redo logs rman Server Processes Recovery Catalog Database (optional) Backup files on disk Server Processes Server Processes Media Management (optional) Backup media

PPOUG, 05-OCT-01 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

PPOUG, 05-OCT-01 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)

PPOUG, 05-OCT-01 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

PPOUG, 05-OCT-01 RMAN Architecture (continued) Media Management Layer (MML) 3 rd 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

PPOUG, 05-OCT-01 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

PPOUG, 05-OCT-01 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

PPOUG, 05-OCT-01 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

PPOUG, 05-OCT-01 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

PPOUG, 05-OCT-01 RMAN Advantages (continued) Logging of all backup operations RMAN writes what/when/where to target controlfile (and catalog if using) Listing and reporting commands

PPOUG, 05-OCT-01 Implementation Decisions Backup to disk (no MML required) Backup to tape (must use MML) Use RMAN with catalog Use RMAN without catalog

PPOUG, 05-OCT-01 Most Moving Parts Target Database datafiles controlfiles Archived redo logs rman Server Processes Recovery Catalog Database Server Processes Server Processes MML Backup media

PPOUG, 05-OCT-01 Simplest Implementation Target Database datafiles controlfiles Archived redo logs rman Server Processes Backup files on disk Server Processes

PPOUG, 05-OCT-01 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

PPOUG, 05-OCT-01 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

PPOUG, 05-OCT-01 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

PPOUG, 05-OCT-01 Tape Based Backup (continued) Disadvantages of Tape MML setup can be frustrating And MML adds complexity

PPOUG, 05-OCT-01 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

PPOUG, 05-OCT-01 Why Use a Catalog? (continued) 8i and 9i Reasons to Use Catalog One centralized repository for all your target databases If not using catalog, finite amount of days of RMAN backup operations stored 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

PPOUG, 05-OCT-01 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

PPOUG, 05-OCT-01 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 ‘ / ’;

PPOUG, 05-OCT-01 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

PPOUG, 05-OCT-01 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

PPOUG, 05-OCT-01 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

PPOUG, 05-OCT-01 RMAN 9i New Features Block Level Recovery Detecting block level corruption v$backup_corruption trace files dbverify RMAN> blockrecover datafile 2 block 30;

PPOUG, 05-OCT-01 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

PPOUG, 05-OCT-01 RMAN 9i Archive Redo Backups New BACKUP … PLUS ARCHIVELOG command RMAN> backup database plus archivelog; 1. Switches online redo logs 2. Backup archivelog all; 3. Backs up files database datafiles 4. Switches online redo logs 5. Backs up any archived redo logs generated during backup

PPOUG, 05-OCT-01 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

PPOUG, 05-OCT-01 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

PPOUG, 05-OCT-01 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;

PPOUG, 05-OCT-01 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;

PPOUG, 05-OCT-01 RMAN Summary RMAN has significant advantages Many different ways to implement Enhancements to RMAN in Oracle9i Q&A