14 Copyright © 2004, Oracle. All rights reserved. Automatic Storage Management.

14Copyright © 2004, Oracle. All rights reserved.

Automatic Storage Management

14-2 Copyright © 2004, Oracle. All rights reserved.

Objectives

After completing this lesson, you should be able to:

• Describe the concepts of Automatic Storage Management (ASM)

• Set up initialization parameter files for ASM and database instances

• Execute SQL commands with ASM file names

• Start up and shut down ASM instances

• Administer ASM disk groups

• Use RMAN to migrate your database to ASM


What Is Automatic Storage Management?

• Portable and high performancecluster file system

• Manages Oracle database files

• Data is spread across disksto balance load

• Integrated mirroring acrossdisks

• Solves many storage management challenges

ASM

FileSystem

VolumeManager

Operating System

Application

Database


ASM Key Features and Benefits

• Stripes files, not logical volumes

• Online disk reconfiguration and dynamic rebalancing

• Adjustable rebalancing speed

• Provide redundancy on a file basis

• ASM only supports Oracle database files

• Cluster aware

• Automatically installed


ASM Concepts

Database

Tablespace

Segment

Extent

Oracleblock

Data file

PhysicalBlock

ASMDisk Group

ASM Disk

ASM File

Allocation UnitFile System

Fileor

Raw Device


ASM General Architecture

ASM Instance

SID=ant

ASM Instance

SID=bee

ASM Disks ASM Disks ASM Disks ASM Disks ASM Disks ASM Disks

ASM Diskgroup Tom ASM Diskgroup Dick ASM Diskgroup Harry

DB Instance

SID=sales

DB Instance

SID=test

DB Instance

SID=sales

DB Instance

SID=test

ASMB

ASMB

FG

FG FG

FG

Node2Node1 Group Servicestom=ant

dick=antharry=ant

Group Services tom=bee

dick=beeharry=bee

DBW0

DBW0DBW0

DBW0ASMB

RBAL RBAL

ARB0

ARBA

…ARB0

ARBA

…

ASMB

RBAL

RBAL RBAL

RBAL


ASM Instance Functionalities

CREATE DISKGROUP

ALTER DISKGROUP DROP DISKGROUP

ALTER SYSTEM RESTRICTED SESSION

ASMinstance

Database instance


ASM Instance Creation


ASM Instance Initialization Parameters

INSTANCE_TYPE = ASM

DB_UNIQUE_NAME = +ASM

ASM_POWER_LIMIT = 1

ASM_DISKSTRING = '/dev/rdsk/*s2', '/dev/rdsk/c1*'

ASM_DISKGROUPS = dgroupA, dgroupB

LARGE_POOL_SIZE = 8MB


Accessing an ASM Instance

Disk group Disk group

Storage system

AS SYSDBA AS SYSOPERASM

instance

All operations Nondestructiveoperations


Dynamic Performance View Additions

Storage system

V$ASM_DISKGROUPV$ASM_CLIENT

V$ASM_DISK

V$ASM_FILE

V$ASM_TEMPLATE

V$ASM_ALIAS

V$ASM_OPERATION

Disk group A Disk group B


ASM Home Page


ASM Performance Page


ASM Configuration Page


Starting Up an ASM Instance

$ sqlplus /nolog

SQL> CONNECT / AS sysdba

Connected to an idle instance.

SQL> STARTUP;

ASM instance started

Total System Global Area 147936196 bytes

Fixed Size 324548 bytes

Variable Size 96468992 bytes

Database Buffers 50331648 bytes

Redo Buffers 811008 bytes

ASM diskgroups mounted


Shutting Down an ASM Instance

SHUTDOWN NORMAL

ASM Instance

Database Instance A Database Instance B

1 1

2

3


ASM Disk Groups

• A pool of disks managed asa logical unit

• Partitions total disk space into uniform sized units

• Spreads each file evenly across all disks

• Uses coarse or fine grain striping based on file type

• Administer disk groups not files

Disk Group

ASMInstance


Failure Group

Controller 1 Controller 2

Failure group 1 Failure group 2

Disk group A

Controller 3

Failure group 3

1 7 13

1 7 131 7 13

1 7 13

1 7 131 7 13

1 7 13

1 7 131 7 13

2

3

4

5

6


Disk Group Mirroring

• Mirror at extent level

• Mix primary and mirror extents on each disk

• External redundancy:Defers to hardwaremirroring

• Normal redundancy: – Two-way mirroring– At least two failure groups

• High redundancy: – Three-way mirroring– At least three failure groups


Disk Group Dynamic Rebalancing

• Automatic online rebalance wheneverstorage configurationchanges

• Only move data proportional to storage added

• No need for manual I/O tuning

• Online migration tonew storage


ASM Administration Page


Create Disk Group Page


Create or Delete Disk Groups

CREATE DISKGROUP dgroupA NORMAL REDUNDANCY

FAILGROUP controller1 DISK

'/devices/A1' NAME diskA1 SIZE 120G FORCE,

'/devices/A2',

'/devices/A3'

FAILGROUP controller2 DISK

'/devices/B1',

'/devices/B2',

'/devices/B3';

DROP DISKGROUP dgroupA INCLUDING CONTENTS;


Adding Disks to Disk Groups

ALTER DISKGROUP dgroupA ADD DISK

'/dev/rdsk/c0t4d0s2' NAME A5,



'/dev/rdsk/c0t7d0s2' NAME A8;

ALTER DISKGROUP dgroupA ADD DISK '/devices/A*';

Disk formatting

Disk group rebalancing


Miscellaneous Alter Commands

ALTER DISKGROUP dgroupA DROP DISK A5;

ALTER DISKGROUP dgroupA DROP DISK A6

ADD FAILGROUP fred DISK '/dev/rdsk/c0t8d0s2' NAME A9;

ALTER DISKGROUP dgroupB REBALANCE POWER 5;

ALTER DISKGROUP dgroupA UNDROP DISKS;

ALTER DISKGROUP dgroupA DISMOUNT;

ALTER DISKGROUP dgroupA CHECK ALL;


Monitoring Long-Running Operations Using V$ASM_OPERATION

Column Description

GROUP_NUMBER Disk group

OPERATION Type of operation: REBAL

STATE State of operation: QUEUED or RUNNING

POWER Power requested for this operation

ACTUAL Power allocated to this operation

SOFAR Number of allocation units moved so far

EST_WORK Estimated number of remaining allocation units

EST_RATE Estimated number of allocation units moved per minute

EST_MINUTES Estimated amount of time (in minutes) for operation termination


ASM Files

Database File

ASM File automatically spread inside Disk Group dgroupA

CREATE TABLESPACE sample DATAFILE '+dgroupA';

1234

1 2 3 4

Automatic ASM fileCreation

RMAN


ASM Filenames

ASM Filename

Fully-qualified

Incompletewith

templateNumeric Alias

Alias withtemplate

Incomplete

ReferenceSingle-fileCreation

Multiple-fileCreation


ASM File Name Syntax

1.

2.

3.

4.

5.

6.

+<group>/<dbname>/<file_type>/<tag>.<file#>.<incarnation#>

+<group>.<file#>.<incarnation#>

+<group>/<directory1>/…/<directoryn>/<file_name>

+<group>

+<group>(<temp>)

+<group>/<directory1>/…/<directoryn>/<file_name>(<temp>)


ASM File Name MappingOracle File Type <File Type> <Tag> Def Template

Control files controlfile CF/BCF CONTROLFILE

Data files datafile <ts_name>_<file#> DATAFILE

Online logs online_log log_<thread#> ONLINELOG

Archive logs archive_log parameter ARCHIVELOG

Temp files temp <ts_name>_<file#> TEMPFILE

Data file backup pieces backupset Client Specified BACKUPSET

Data file incrementalbackup pieces

backupset Client Specified BACKUPSET

Arch log backup piece backupset Client Specified BACKUPSET

Data file copy datafile <ts_name>_<file#> DATAFILE

Initialization parameters init spfile PARAMETERFILE

Broker configurations drc drc DATAGUARDCONFIG

Flashback logs rlog <thread#>_<log#> FLASHBACK

Change tracking bitmaps CTB BITMAP CHANGETRACKING

Auto backup AutoBackup Client Specified AUTOBACKUP

Data Pump dump set Dumpset dump DUMPSET

Cross-platform converted data files

XTRANSPORT


ASM File Templates

System Template StripedExternal Normal High CONTROLFILE fineunprotected 2-way mirror 3-way mirror

DATAFILE coarseunprotected 2-way mirror 3-way mirror

ONLINELOG fineunprotected 2-way mirror 3-way mirror

ARCHIVELOG coarseunprotected 2-way mirror 3-way mirror

TEMPFILE coarseunprotected 2-way mirror 3-way mirror

BACKUPSET coarseunprotected 2-way mirror 3-way mirror

XTRANSPORT coarseunprotected 2-way mirror 3-way mirror

PARAMETERFILE coarseunprotected 2-way mirror 3-way mirror

DATAGUARDCONFIG coarseunprotected 2-way mirror 3-way mirror

FLASHBACK fineunprotected 2-way mirror 3-way mirror

CHANGETRACKING coarseunprotected 2-way mirror 3-way mirror

AUTOBACKUP coarseunprotected 2-way mirror 3-way mirror

DUMPSET coarseunprotected 2-way mirror 3-way mirror

Unprotected

2-way

Mirror

3-way

Mirror


ALTER DISKGROUP dgroupA ADD TEMPLATE reliable ATTRIBUTES (MIRROR);

ALTER DISKGROUP dgroupA DROP TEMPLATE reliable;

ALTER DISKGROUP dgroupA DROP FILE '+dgroupA.268.8675309';

ALTER DISKGROUP dgroupA ADD DIRECTORY '+dgroupA/mydir';

ALTER DISKGROUP dgroupA ADD ALIAS '+dgroupA/mydir/datafile.dbf' FOR '+dgroupA.274.38745';

ALTER DISKGROUP dgroupA DROP ALIAS '+dgroupA/mydir/datafile.dbf';

Template and Alias Examples


Retrieving Aliases

SELECT reference_index INTO :alias_idFROM V$ASM_ALIAS WHERE name = '+dgroupA';

SELECT reference_index INTO :alias_id FROM V$ASM_ALIASWHERE parent_index = :alias_id AND name = 'mydir';

SELECT name FROM V$ASM_ALIAS WHERE parent_index = :alias_id;


SQL Commands and File Naming

CREATE CONTROLFILE DATABASE sample

RESETLOGS ARCHIVELOG

MAXLOGFILES 5 MAXLOGHISTORY 100

MAXDATAFILES 10 MAXINSTANCES 2

LOGFILE GROUP 1 ('+dgroupA','+dgroupB') SIZE 100M,

GROUP 2 ('+dgroupA','+dgroupB') SIZE 100M

DATAFILE '+dgroupA.261.12345678' SIZE 100M

DATAFILE '+dgroupA.262.87654321' SIZE 100M;


DBCA and Storage Options


Database Instance Parameter Changes

…

INSTANCE_TYPE = RDBMS

LOG_ARCHIVE_FORMAT

DB_BLOCK_SIZE

DB_CREATE_ONLINE_LOG_DEST_n

DB_CREATE_FILE_DEST

DB_RECOVERY_FILE_DEST

CONTROL_FILES

LOG_ARCHIVE_DEST_n

LOG_ARCHIVE_DEST

STANDBY_ARCHIVE_DEST

LARGE_POOL_SIZE = 8MB

…


Migrating Your Database to ASM Storage

1. Shut down your database cleanly

2. Shutdown the database and modify your server parameter file to use Oracle Managed Files (OMF)

3. Edit and execute the following RMAN script:

STARTUP NOMOUNT;RESTORE CONTROLFILE FROM '/u1/c1.ctl';ALTER DATABASE MOUNT;BACKUP AS COPY DATABASE FORMAT '+dgroup1';SWITCH DATABASE TO COPY;SQL "ALTER DATABASE RENAME '/u1/log1' TO '+dgroup1' ";# Repeat RENAME command for all online redo log members ...ALTER DATABASE OPEN RESETLOGS;SQL "ALTER DATABASE TEMPFILE '/u1/temp1' DROP";


Summary

In this lesson, you should have learned how to:

• Describe the concepts of Automatic Storage Management (ASM)

• Set up initialization parameter files for ASM and database instances

• Execute SQL commands with ASM file names

• Start up and shut down ASM instances

• Administer ASM disk groups

• Use RMAN to migrate your database to ASM


Practice 14 Overview:Using ASM

This practice covers the following topics:

• Creating an ASM instance

• Creating tablespaces that use ASM storage

• Viewing ASM information

• Migrating a tablespace to use ASM storage

14 Copyright © 2004, Oracle. All rights reserved. Automatic Storage Management.

Documents

asm asm

asm slide

asm db

asm instances

sysoper asm instance

asm instance functionalities

asm instance creation

file basis asm