Zero Downtime Backup solution for Oracle10g

© 2004 Hewlett-Packard Development Company, L.P.

The information contained herein is subject to change without notice

Zero Downtime Backup

solution for Oracle10g

Storage Grid Seminar

Oktober 2005

Frankfurt, München, Hamburg

Jaime Blasco

HP/Oracle CTC (Cooperative Technology Center) EMEA Competence Center

Agenda

•

Oracle Backup concepts

•

Split/Mirror Backup

•

Zero Downtime Backup / Instant Recovery for

Oracle

HP achieves world record

backup and restore

achieved with the following equipment:

• Superdome with 32CPU's • XP1024

• HP Tape library (ESL9595) with 16 Ultrium2 drives

• Oracle 9iR2 (9.2.0.2.0) for recovery catalog and target

database

• OpenView Data Protector 5.0

• 4.3TB database on file system using the TPC-H standard

setup: 8 tables partitioned over ~150 Tablespaces and ~ 260 datafiles.

3.16TB/hr Oracle online backup 1.23TB/hr Oracle restore

•

Based on the status of the Oracle Server, the Backup

can be:

− Offline Backup

− Online Backup

•

Oracle distinguishes between:

− User Managed Backup: OS copy commands

− Server Managed Backup: RMAN (Recovery MANager)

Oracle DB Backup and Recovery

concepts

Oracle DB Backup and Recovery

concepts

Backup Methods

Physical backup Closed database

Noarchivelog mode

Closed or open database

Consistent Whole Database Backup

(Closed Database Backup)

Datafiles Control

files Passwordfile

Online or offline storage Parameter file Redo log files

Open Database Backup

Datafiles Control files

Parameter file Archived redo log files Password file Online redo log files

Open Database Backup Options

sql>alter tablespace users begin backup; sql>alter system begin backup;

sql>alter tablespace users end backup; sql>alter system end backup;

Tablespace in backup mode

When a tablespace is put into backup mode, the following three things happen:

2. Oracle checkpoints the tablespace, flushing all changes

from shared memory to disk.

3. The SCN markers for each datafile in that tablespace

are "frozen" at their current values. Even though further updates will be sent to the datafiles, the SCN markers will not be updated until the tablespace is taken out of backup mode.

4. Oracle switches to logging full images of changed

database blocks to the redologs. Instead of recording how it changed a particular block (the change vector), it will log the entire image of the block after the change. This is why the redologs grow at a much faster rate while hot backups are going on.

Data Protector integration with

Oracle

Oracle 9i/10g server

RMAN tablespace 2 tablespace 1 control files target database channel C2 channel C1 channel C_n recovery catalog API DP Oracle agent archive redo log data filedata files

Agenda

•

Basic Oracle Backup Concepts

•

Zero Downtime Backup / Instant Recovery

concepts

•

ZDB and Oracle10g

tape backup no longer meets the need

for high-speed recovery

hp is shifting focus from backup to recovery

recovery point objective

(how old is the data to which I recover?) within the past hour within past 24 hours minutes several hours tape backup INSTANT RECOVERY

recovery time objective

(how long does it take?)

Faster data recovery

methods

low-cost disk recovery

backup server production data t application server recovery images on disk t₀ tape library recovery images on tape management Instant Recovery low-cost storage application server

low-cost disk recovery

management application server copy t productio n data backup server tape zero-downtime backup

Advanced backup to disk

management backup server application server tape low-cost storage

zero downtime backup process

running environment

backup session start

snapshot/snapclone

backup session completion

1. The application writes data to the array, using RAID to control

distribution of the data across physical disks.

2. Backup session starts. 3. DB is put into backup

mode/offline.

4. snapshots / snapclones are taken.

5. DB is taken out of Backup mode/put back on-line.

6. If a tape backup is specified,

the snapshot of data is backed up to tape.

7. Backup session ends.

O O O O O O

R R R

O O O R R R O O O

Zero Downtime Backup

Key features

• Perfectly integrated into Data Protector

• Easily implement backup jobs without custom script

development

• Use of Snapshots or Snapclones on the EVA array,

BC or CA on the XP.

• Application is not impacted during the backup process

• A dedicated backup server runs the backup from the

Snapshot/Snapclone or BC

O O

O - Original

R R

• Zero Downtime Backup

• Snapshots/snapclones can be created on the fly

• Backup host processes the data

• Snapshots/snapclones get removed at the end of the backup

R - Replica

Backup host Application host

EVA

Zero Downtime Backup snapshot

backup concept for EVA

instant recovery concept

(general)

• all restores from tape

• restore to the application host (or

backup host if disk array supports this) • either host involved in data processing

• fast, automated restore directly from the replica

• minutes instead of hours

• no host involved in data processing

Tape restore approach

O R

original replica

Instant Recovery for EVA

Key features

•

Builds on the ZDB solution

•

Keeps a defined number of shadow copies on the

EVA for fast recovery

•

Recover your data in minutes rather than hours

from tape

•

Snapclone only

Builds on zero-downtime backup to retain multiple images on disk for selective recovery to any point-in-time

image.

 Data Protector fully

automates the protection

process, including creation and rotation of mirrors or snapshots.

_{for recovery, administrator}

selects a specific recovery

image from the graphical user interface management production data t application server media agent tape library recovery images on tape recovery images on disk t₀ t_-1 t_-2 single scheduler, single recovery interface

instant recovery – multiple

version on disk

replica storage –

snapshot / snapclone rotation

replica storage: Snapshot, -clone in rotation Production volume recovery images on tape catalog database:

- files, versions, hosts

- media, drives, libraries Application server Backup server FC SAN • replicas (snapshots or snapclones) are rotated

• the backup re-uses the oldest replica each time it runs

• only snapclones are used for Instant

Recovery (recovers Tbytes of data in

instant recovery on EVA

(example)

Original Unit Replica Unit x (snapclone)

before IR during IR after IR

- RU2 is selected for instant recovery and becomes the original disk

- original disk is removed

application host EVA RU2 OU RU3 RU1 EVA RU2 RU3 RU1 OU RUx

Agenda

•

Basic Oracle Backup Concepts

•

Zero Downtime Backup / Instant Recovery

concepts

•

ZDB and Oracle10g

Oracle ZDB integration steps

•

check Oracle requirements

− Oracle file layout

− recovery catalog database required

− Net8 installed and configured

− whether Oracle is required on backup system depends on RMAN backup method

•

install Data Protector components (disk array,

Oracle) on application and backup server

•

install Data Protector licenses

configure the integration

•

create backup specification

Oracle setup

Redo logs original _units replica _{units Control files}

XP / VA / EVA

RMAN online / offline thru

application host (proxy copy)

Oracle RMAN:

backup set – proxy copy

− up to Omniback 4.1: only backup set is supported

− data protector 5.0 & 5.1

supports only “proxy copy” (except with Oracle 8.0.x)

• whitepaper has introduced support for backups set ZDB for DP 5.1 (HP-UX)

− data protector 5.5 supports both

Oracle backup

RMAN user - managed

proxy copy backup set

•

RMAN offers two types of backup methods:

backup set and proxy copy

•

Data Protector 5.5 supports proxy copy and

backup method: proxy copy

•

what is proxy copy?

− media management vendor software (data protector) takes over data movement

− Oracle introduced proxy copy with version 8i (8.1.5)

•

what does this mean to the DP ZDB integration?

− backup server doesn’t require Oracle installation

− proxy copy returns a list of datafiles

− list of datafiles are “copied” via replica to the backup system

− datafiles are backed up on the backup server

− complete datafiles are backed up

•

data protector 5.0 and 5.1 support only proxy

backup method: backup set

•

what is backup set?

− Oracle sends/receives (backup/restore) data streams to/from the media management backup tool

− RMAN specific format

− also called stream backup

•

what does this mean to the Data Protector ZDB

integration?

− backup server requires Oracle installation

− data files are “copied” via replica to the backup system

− Oracle instance is started on the backup server and backup is performed

configuration

• backup method is determined when configuring the

integration

• for proxy copy

util_oracle8.exe –CONFIG_SMB_PROXY

<ORACLE_SID> Oracle SID

<ORACLE_HOME> Oracle home directory

<TARGET_DATABASE_LOGIN> connection string target db <RECOVERY_CATALOG_LOGIN> connection string catalog db <CONTROL_FILE_LOCATION> location for backup control file

• for backup set

util_oracle8.exe –CONFIG_SMB_BACKUP_SET

<ORACLE_SID> Oracle SID

<ORACLE_HOME> Oracle home directory

<TARGET_DATABASE_LOGIN> connection string to target db <RECOVERY_CATALOG_LOGIN> connection string to catalog db <CONTROL_FILE_LOCATION> location for backup control file

[<INIT_FILE>] original location of

create backup specification

•

combination of normal oracle integration and disk

array parameters

1. select split mirror or snapshot backup

6. select disk array options

overall procedure of a IR/Roll

Forward

1.

Oracle database has to be manually shut down

IR/roll forward is started via DP GUI

− all Oracle data files get “restored” caused by a re-sync from the replica to the original unit

− DP creates RMAN script according the user specified options

− RMAN script is started to recover the database

• missing archive logs and/or incremental backups are restored automatically by RMAN

• recovery is done until the specified time

− most recent time (now), specified time, logseq/thread, system change number (SCN)

Agenda

•

Basic Oracle Backup Concepts

•

Zero Downtime Backup / Instant Recovery

concepts

•

ZDB and Oracle10g

LIVE DEMONSTRATION OF

„ZERO DOWNTIME BACKUP“

AND „INSTANT RECOVERY“ !

Demo environment for ZDB/IR

OU

OU: original unit RU: replica unit

RU RU Backup Host Application Host E V A OU oracle2 oracle1 oracle3 DP Cell Server SAN SAN LAN w2k hp-ux hp-ux BACKU P