Introduction to Oracle Backup and Recovery

Slides:



Advertisements
Similar presentations
INTRODUCTION TO ORACLE Lynnwood Brown System Managers LLC Backup and Recovery Copyright System Managers LLC 2008 all rights reserved.
Advertisements

5 Copyright © 2006, Oracle. All rights reserved. Database Recovery.
Advanced Databases DBA: Backups 1. Advanced Databases Agenda Define backup Discuss Backup Terminology Explain various backup and restore options in Oracle.
Database Backup and Recovery
RMAN Restore and Recovery
Backup and Recovery (2) Oracle 10g CAP364 1 Hebah ElGibreen.
Backup and Recovery Part 1.
Chapter 12 Performing Incomplete Recovery. Background Viewed as one of the more difficult chapters to write Thought it was important to put in material.
Harvard University Oracle Database Administration Session 11 Database Recovery.
CHAPTER 16 User-Managed Backup and Recovery. Introduction to User Managed Backup and Recovery Backup and recover is one of the most critical skills a.
Configuring Recovery Manager
4 Copyright © 2008, Oracle. All rights reserved. Configuring Backup Specifications.
Chapter 5 Configuring the RMAN Environment. Objectives Show command to see existing settings Configure command to change settings Backing up the controlfile.
CHAPTER 5 Managing Control Files, Online Redo Logs, and Archiving.
9 Copyright © Oracle Corporation, All rights reserved. Oracle Recovery Manager Overview and Configuration.
CHAPTER 17 Configuring RMAN. Introduction to RMAN RMAN was introduced in Oracle 8.0. RMAN is Oracle’s tool for backup and recovery. RMAN is much more.
Oracle9i Database Administrator: Implementation and Administration
Backup Concepts. Introduction Backup and recovery procedures protect your database against data loss and reconstruct the data, should loss occur. The.
CHAPTER 18 RMAN Backups and Reporting. Introduction to RMAN Backups and Reporting The focus of this chapter is backups of: Datafiles Control files Archived.
Agenda  Overview  Configuring the database for basic Backup and Recovery  Backing up your database  Restore and Recovery Operations  Managing your.
Oracle backup and recovery strategy
Using RMAN to Perform Recovery
CHAPTER 16 User-Managed Backup and Recovery. Introduction to User Managed Backup and Recovery Backup and recover is one of the most critical skills a.
IS 4510 – Database Administration Module – 2 Database Backup 10/24/20141Compiled by: Zafar Iqbal Khan.
Backup & Recovery Concepts for Oracle Database
13 Copyright © Oracle Corporation, All rights reserved. RMAN Complete Recovery.
Oracle Recovery Manager (RMAN) 10g : Reloaded
PPOUG, 05-OCT-01 Agenda RMAN Architecture Why Use RMAN? Implementation Decisions RMAN Oracle9i New Features.
SRUTHI NAGULAVANCHA CIS 764, FALL 2008 Department of Computing and Information Sciences (CIS) Kansas State University -1- Back up & Recovery Strategies.
5 Copyright © 2004, Oracle. All rights reserved. Using Recovery Manager.
5 Copyright © 2008, Oracle. All rights reserved. Using RMAN to Create Backups.
Chapter 7 Making Backups with RMAN. Objectives Explain backup sets and image copies RMAN Backup modes’ Types of files backed up Backup destinations Specifying.
11 Copyright © Oracle Corporation, All rights reserved. RMAN Backups.
11 Copyright © Oracle Corporation, All rights reserved. RMAN Backups.
15 Copyright © 2005, Oracle. All rights reserved. Performing Database Backups.
Backup & Recovery Backup and Recovery Strategies on Windows Server 2003.
16 Copyright © 2007, Oracle. All rights reserved. Performing Database Recovery.
RMAN: Your New Best Friend for Backup and Recovery Ruth Gramolini ORACLE DBA Vermont Department of Taxes.
15 Copyright © 2007, Oracle. All rights reserved. Performing Database Backups.
9 Copyright © 2004, Oracle. All rights reserved. Flashback Database.
The protection of the DB against intentional or unintentional threats using computer-based or non- computer-based controls. Database Security – Part 2.
CHAPTER 5 Managing Control Files and Online Redo Logs.
A Guide to Oracle9i1 Database Instance startup and shutdown.
Chapter 8Oracle9i DBA II: Backup/Recovery and Network Administration 1 Chapter 8 Complete Recovery with Recovery Manager.
Week 3 Lecture 1 The Redo Log Files and Diagnostic Files.
IT Database Administration Section 09. Backup and Recovery Backup: The available options Full Consistent (cold) Backup Database shutdown, all files.
14 Copyright © 2005, Oracle. All rights reserved. Backup and Recovery Concepts.
Backup Concepts. Introduction Backup and recovery procedures protect your database against data loss and reconstruct the data, should loss occur. The.
3 Copyright © 2006, Oracle. All rights reserved. Using Recovery Manager.
10 Copyright © Oracle Corporation, All rights reserved. User-Managed Backups.
Chapter 1Oracle9i DBA II: Backup/Recovery and Network Administration 1 Chapter 1 Backup and Recovery Overview MSCD642 Backup and Recovery.
© 2006 Northgate Information Solutions plc and its associated companies. All rights reserved. Slide 1.
Overview of Oracle Backup and Recovery Darl Kuhn, Regis University.
12 Copyright © Oracle Corporation, All rights reserved. User-Managed Complete Recovery.
18 Copyright © 2004, Oracle. All rights reserved. Backup and Recovery Concepts.
6 Copyright © 2007, Oracle. All rights reserved. Performing User-Managed Backup and Recovery.
2 Copyright © 2007, Oracle. All rights reserved. Configuring for Recoverability.
2 Copyright © 2006, Oracle. All rights reserved. Configuring Recovery Manager.
8 Copyright © 2007, Oracle. All rights reserved. Using RMAN to Duplicate a Database.
18 Copyright © 2004, Oracle. All rights reserved. Recovery Concepts.
14 Copyright © 2005, Oracle. All rights reserved. Backup and Recovery Concepts.
10 Copyright © 2007, Oracle. All rights reserved. Using RMAN Enhancements.
9 Copyright © 2004, Oracle. All rights reserved. Incomplete Recovery.
14 Copyright © 2007, Oracle. All rights reserved. Backup and Recovery Concepts.
Backup and Recovery (1) Oracle 10g Hebah ElGibreen CAP364.
Performing Database Backups
Oracle9i Database Administrator: Implementation and Administration
Index Index.
Performing Database Recovery
Chapter 5 The Redo Log Files.
Presentation transcript:

Introduction to Oracle Backup and Recovery Darl Kuhn, Regis University

Backup and Recovery Planning How valuable is your data? How much data can you lose? Is the data easily recreated? Mean time to recovery requirements (MTTR) Availability requirements Disaster recovery requirements (DR) Test Plan How much money can you spend?

Backup and Recovery DBAs must be knowledgeable of backup and recovery Arguably the most critical skill for a DBA to possess Must know how to architect backups Must know how to recover in the event of a failure

Oracle Architecture When dealing with backup and recovery, you must know the differences between an Oracle instance and database. When backing up files in an Oracle database, you will mainly be concerned with: control files, datafiles, and archive redo log files. Other file types to backup might be initialization files and network files. Keep in mind for online backups, you never backup the online redo log files, why?

Noarchivelog Mode Noarchivelog mode databases can only be backed up when the database is shutdown.

Archivelog Mode Archivelog mode is required for Hot Backups and RMAN Online backups. Archivelog mode allows you to take online backups, in other words, the database is up and running while the backup is taking place.

Archivelog Mode Continued Advantages Enables mechanism for recovery of every committed transaction Enables online backups (Hot or RMAN) Disadvantages Requires additional storage Additional administrative overhead (you need to backup and periodically remove archive redo log files) Additional process (ARCn) and I/O

Enabling Archivelog Mode SQL> shutdown immediate; SQL> startup mount; SQL> alter database archivelog; SQL> alter database open; It’s easy to enable archive log mode. However, now you need to consider where the archive redo logs are being written, and how long to keep them on disk before removing them, and how to remove them from disk (let RMAN do it or manually remove them).

Location and Management of Archive Redo Logs If the location for the archive redo logs becomes full and Oracle cannot write archive redo logs to disk, your database will hang. In a production environment, you must give some detailed thought to the location of the archive redo log files. You need to ensure there is enough space and that the archive redo logs are backed up and removed on a regular basis. Do you want to use the Fast Recovery Area (or not). How long do you keep archive redo logs on disk? How do you remove the archive redo logs?

Types of Backups User Managed Physical Backups Cold (offline) Hot (online) User Managed Logical Backups Old Export and Import utilities Data Pump export and import (10g and higher) Recovery Manager (RMAN) Offline physical Online physical 3rd Party Tools

User Managed Cold Backup (offline) Database shutdown during backup Uses operating system copy command Cold Backup Steps: 1. Determine location of datafiles, controlfiles, and online redo logs 2. Shutdown immediate, transactional, or normal 3. Copy files to backup location 4. Startup database

User Managed Hot Backup (online) Database must be in archivelog mode Tablespaces must be altered in and out of backup mode Database remains online during backup While tablespace in backup mode: When a block first changes Full block written to redo stream Not just the atomic change vector Can be significant performance hit Very common misperception that DBWn stops writing to datafiles during Hot Backup, not true!

User Managed Hot Backup Procedure Hot Backup has more moving parts than a Cold: 1. Ensure database in archivelog mode 2. Determine which files to backup 3. Switch on-line redo logs 4. Alter tablespaces into backup mode (serial or parallel) 5. Use an OS utility to copy datafiles to backup location 6. Alter tablespaces out of backup mode 7. Switch on-line redo logs 8. Copy any archive redo logs generated during backup 9. Backup the controlfile via "alter database backup controlfile to <location/name>";

User Managed Logical Backups Export utility Data Pump export: 10g and higher Greatly enhanced performance Schedule data pump jobs within the server Control and monitor data pump jobs from a different session Enhanced ETL operations The old export utility and the newer Data Guard export utility are referred to as “logical” because the backup file is not a physical copy of the data blocks, rather it’s a backup of the SQL that is required to recreate the objects and then the data to repopulate those objects.

Recovery Manager (RMAN) RMAN is a tool that can be used for backup, restore, and recovery of Oracle databases First shipped with Oracle version 8.0 Oracle's recommended tool for B&R No extra license required Enterprise Edition contains all RMAN features, other editions contain subset of RMAN features. First stable release of RMAN was around 8.1.6. Many DBAs who tried to use RMAN before that release have bad memories of RMAN. But since 8.1.6, RMAN has been very reliable and stable. Some features of RMAN are only available in the Enterprise Edition of Oracle. RMAN does ship with other editions, but does not contain the full feature set.

RMAN Advantages Easy to use command line mode to issue backup, restore, and recover commands Accessible through Enterprise Manager Tablespaces not put in backup mode (this is a huge advantage over Hot Backups) Incremental backups Block corruption detection Configurable I/O features (parallelism) Logging of backup operations Integrates with Media Management Layer (MML) software Compression and encryption Cross-platform data conversion Advanced reporting capabilities Data Recovery Advisor Automatic backup of the control file and server parameter file (spfile) RMAN has many, many advantages over user managed Hot/Cold backups. You really should be using RMAN (and not user managed Hot/Cold) backups for backing up your Oracle databases.

RMAN 9i New Features Backup optimization Restore optimization Block level recovery New features for archive redo log backups Configurable persistent settings, automatic backup of controlfile, spfile Simplified syntax Retention policy RMAN was greatly enhanced in Oracle Database 9i. Many DBAs began to use RMAN with the release of 9i.

RMAN 10g New Features Make use of Flash Recovery Area (renamed to Fast Recovery Area in 11g) Change tracking Incremental merge Backup duration Compressed backups Automatic channel failover Restore failover Restore preview Automatic creation of missing datafiles Recovery through resetlogs With each release of Oracle, there are many significant improvements to RMAN functionality.

RMAN 11g New Features Data Recovery Advisor. Enhancements to compression. Ability to backup large datafiles in parallel. Enhancements to cloning/duplicating. Oracle Secure Backup enhancements. More integration with Data Guard.

RMAN 12c New Features Not yet released, Oracle Database 12c. Currently in Beta. Should be available ???

RMAN Backups Should you use a recovery catalog? Should you use a MML? What should be the retention policy? Online or Offline Database must be in archivelog mode for online RMAN backups Can be as simple as: RMAN> backup database;

Failures Happen Non-Media Failure Media Failure Process failure Statement failure User error Instance failure Media Failure Oracle unable to perform I/O on database file Requires DBA intervention

Crash vs. Media Recovery On startup, Oracle determines whether crash or media failure situation exists: IF (cf SCN = df SCN) THEN Startup normally; ELSE IF (cf stop SCN = infinity) THEN SMON performs crash recovery; ELSE IF (cf SCN > df SCN) THEN Throw media failure error; ELSE IF (cf SCN < df SCN) THEN Throw controlfile too old error; END IF; Media failure means there is a critical file that Oracle needs that it cannot read when trying to open the database. This could be a control file, an online redo log file, or a datafile.

Restore and Recovery Restore is copying datafiles back from the backup set Recovery is apply redo to the datafiles via a “recover” command Many, many different B&R scenarios Restore and recovery procedure varies widely depending on: Type of backup Type of failure (datafile, controlfile, redo) Archivelog or noarchivelog mode

Noarchivelog Mode Restore Restore from Cold Backup or an RMAN offline backup Restores to the point in time the backup was taken No redo available to restore transactions Most likely will result in loss of data

Archivelog Mode Restore and Recovery Restore datafiles from: Cold backup Hot backup RMAN online or offline backup Issue “recover” command to apply redo SQL> recover database .... Recovery can be either complete or incomplete

Complete Recovery Complete recovery means that you can recover all transactions ever committed in the database You're restoring the database to the point in time right before the failure occurred Complete recovery only available for archivelog mode databases Complete does not mean that you have to restore and recover all datafiles Only have to restore and recover datafiles that have experienced media failure

Incomplete Recovery All transactions are not restored Types of incomplete recovery: Change (SCN) Time Log Basic procedure: Copy all datafiles back from the backup set Rollforward to desired point SQL> alter database open resetlogs;

Summary Develop B&R plan that meets business requirements Wide variety of methods to backup and recover your database Use RMAN “Your backup is only as good as the last time you tested it...”