administering storage in rac parti

8/6/2019 Administering Storage in RAC PartI

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Administering Storage in RAC(Part I)


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Objectives

After completing this lesson, you shouldbeable to do the following: Describe automatic storage management(ASM)

Install the ASM software Set up initialization parameter files forASM and database instances Start up and shut down ASM instancesAdd ASM instances to the target list of

Database Control Use Database Control to administer ASM ina RAC environment


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What Is Automatic StorageManagement?

Is a purpose-built cluster file system andvolume manager

Manages Oracle database files Spreads data across disksto balance load

Provides integrated mirroringacross disks

Solves many storagemanagement challenges

ASMFilesystem

Logical

volumemanager

Operatingsystem

Application

Database


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ASM: Key Features and Benefits

Stripes files rather than logical volumes Enables online disk reconfiguration anddynamic rebalancing

Provides adjustable rebalancing speed Provides redundancy on a file basis Supports only Oracle files Is cluster aware Is automatically installed as part of thebase code set


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ASM: New Concepts

Database

Tablespace

Segment

Extent

Oracleblock

Data file

Physicalblock

ASMdisk group

ASM disk

ASM file

Allocation

unit

File system

fileorraw device


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ASM: General Architecture

ASM

InstanceSID=ant

ASM

InstanceSID=bee

ASM disks ASM disks ASM disks ASM disks ASM disks ASM disks

ASM Disk group Tom ASM Disk groupDick

ASM Disk groupHarry

DBInstanceSID=sale

s

DBInstanc

e

SID=test

DBInstanceSID=sale

s

DBInstanc

e

SID=test

ASMB

ASMB

FG

FG FG

FG

Node2Node1

GroupServicestom=antdick=antharry=ant

GroupServicestom=beedick=beeharry=bee

DBW0

DBW0DBW0

DBW0ASMB

RBAL RBAL

ARB0

ARBA

ARB0

ARBA

ASMB

RBAL

RBAL RBAL

RBAL


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Notes only slide


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ASM Instance and Crash Recovery inRAC

Disk groupA

Node2

+ASM2

Node1

+ASM1

Both instancesmount

disk group

Disk groupA

Node2

+ASM2

Node1

+ASM1

ASM instancefailure

Disk groupA

Node2

+ASM2

Node1

Disk grouprepaired

by survivinginstance

Disk Group A

Node2

+ASM2

Node1

+ASM1

Only oneinstance

mounts diskgroup

Disk Group A

Node2

+ASM2

Node1

+ASM1

ASM instancefailure

Disk Group A

Node2

+ASM2

Node1

Disk grouprepaired

when nextmounted

ASM crashrecovery

ASM instancerecovery


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ASMLibs

An ASMLib is a storage-managementinterface between Oracle kernel and diskstorage.

You can load multiple ASMLibs. Purpose built drivers can provide:

o Device discoveryoMore efficient I/O interfaceo Increased performance and reliability

Oracle freely delivers an ASMLib on Linux.

Several participating storage vendors suchas EMC and HP are joining this initiative.


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Oracle Linux ASMLib Installation:Overview

1. Install the ASMLib packages on eachnode:o http://otn.oracle.com/tech/linux/asmlibo Install oracleasm-support, oracleasmlib, and

kernel-related packages2. Configure ASMLib on each node:o Load ASM driver and mount ASM driver filesystem

o Use the oracleasm script with the configureoption

3. Make disks available to ASMLibbymarking disks using oracleasm creatediskon one node.4. Make sure that disks are visible onother nodes using oracleasm scandisks.5. Use appropriate discovery strings forthis ASMLib.


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Oracle Linux ASMLib Installation

Install the packages as the root user:

Run oracleasm with the configure option:

o Provide oracle UID as the driver owner.o Provide dba GID as the group of the driver.o Load the driver at system startup.

# rpm -i oracleasm-support-version.arch.rpm \oracleasm-kernel-version.arch.rpm \oracleasmlib-version.arch.rpm

# /etc/init.d/oracleasm configure


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Notes only page


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ASM Library Disk Creation

Identify the device name for the disksthat you want to use with the fdisk lcommand.

Create a single whole-disk partition onthe disk device with fdisk.

Enter a command similar to the followingto mark the shared disk as an ASM disk:

To make the disk available on the othernodes, enter the following as root on eachnode:

Set the ASM_DISKSTRING parameter

/etc/init.d/oracleasm createdisk disk1 /dev/sdbn

# /etc/init.d/oracleasm scandisks


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Notes only page


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ASM Administration

ASM instance

Disk groups and disks

Files

00100010


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ASM Instance Functionalities

CREATE DISKGROUP

ALTER DISKGROUP DR OP DISKGROUP

ALTER SYSTEM RESTRICTED SESSION

ASMinstance

Databaseinstance


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ASM Instance Creation


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ASM Instance InitializationParameters

INSTANCE_TYPE = ASMDB_UNIQUE_NAME = +ASMASM_POWER_LIMIT = 1ASM_DISKSTRING = '/dev/rdsk/*s2', '/dev/rdsk/c1*'

ASM_DISKGROUPS = dgroupA, dgroupBLARGE_POOL_SIZE = 8MB

PROCESSES = 25 + 15*


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RAC and ASM Instances Creation


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ASM Instance InitializationParameters and RAC

CLUSTER_DATABASE: This parameter must beset to TRUE.

ASM_DISKGROUP:oMultiple instances can have different

values.o Shared disk groups must be mountedby eachASM instance.

ASM_DISKSTRING:oMultiple instances can have differentvalues.

o With shared disk groups, every instanceshouldbe able to see the common pool of

physical disks.ASM_POWER_LIMIT: Multiple instances canhave different values.


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Discovering New ASM Instances withEM

If new ASM targets are not discovered:

$ emctl config agent addtarget

$ emctl stop agent

$ emctl start agent


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Accessing an ASM Instance

Diskgroup

Diskgroup

Storagesystem

AS SYSDBA ASMinstanc

e

Alloperations


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Dynamic Performance View Additions

Storagesystem

V$ASM_DISKGROUPV$ASM_CLIENT

V$ASM_DISK

V$ASM_FILE

V$ASM_TEMPLATE

V$ASM_ALIAS

V$ASM_OPERATION

Disk groupA

Disk groupB


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ASM Home Page


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ASM Performance Page


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ASM Configuration Page


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Starting Up an ASM Instance

$ sqlplus /nologSQL> CONNECT / AS sysdbaConnected to an idle instance.SQL> STARTUP;

ASM instance startedTotal System Global Area 147936196 bytesFixed Size 324548 bytesVariable Size 96468992 bytesDatabase Buffers 50331648 bytesRedo Buffers 811008 bytesASM diskgroups mounted


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Shutting Down an ASM Instance

ASM

SHUTDOWN NORMAL

DB

SHUTDOWN

ASM

SHUTDOWN IMMEDIATE

DB instanceimmediatelyaborted


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ASM Administration

ASM instance


Files

00100010


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ASM Disk Group

Is a pool of disks managedasa logical unit

Partitions total diskspace into uniform-sizedunits

Spreads each file evenlyacross all disks

Provides coarse- or fine-

grain striping based onfile type

Administers disk groups,not files

Diskgroup

ASMinstanc

e


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Failure Group

Controller1

Controller2

Failuregroup 1

Failuregroup 2

Disk groupA

Controller3

Failuregroup 3

1 7 13

1 7 13

1 7 13

1 7 13

1 7 13

1 7 13

1 7 13

1 7 13

1 7 13

2

3

4

5

6


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Disk Group Mirroring

Mirror at AU levelMix primary and mirrorAUs on each disk External redundancy:

Defers to hardwaremirroringNormal redundancy:

o Two-way mirroringoAt least two failure groups

High redundancy:o Three-way mirroringoAt least three failure groups


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Disk Group Dynamic Rebalancing

Automatic onlinerebalancing wheneverstorage configurationchanges

Only move dataproportional tostorage added

No need for manualI/O tuning

Online migration tonew storage


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ASM Administration Page


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Create Disk Group Page


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ASM Disk Groups with EM in RAC


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Disk Group Performance Page andRAC


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Create or Delete Disk Groups

CREATE DISKGROUP dgroupA NORMAL REDUNDANCYFAILGROUP 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;


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Adding Disks to Disk Groups

ALTER DISKGROUP dgroupA ADD DISK'/dev/rdsk/c0t4d0s2' NAME A5,'/dev/rdsk/c0t5d0s2' NAME A6,'/dev/rdsk/c0t6d0s2' NAME A7,'/dev/rdsk/c0t7d0s2' NAME A8;

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

Diskformatting

Disk grouprebalancing


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Miscellaneous Alter Commands

ALTER DISKGROUP dgroupADROP DISKA5;

ALTER DISKGROUP dgroupADROP DISKA6ADD FAILGROUP fred

DISK '/dev/rdsk/c0t8d0s2' NAME A9;

ALTER DISKGROUP dgroupB REBALANCE POWER 5;

ALTER DISKGROUP dgroupAUNDROP DISKS;

ALTER DISKGROUP dgroupADISMOUNT;

ALTER DISKGROUP dgroupACHECK ALL;


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Notes only page


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Monitoring Long-Running OperationsUsing V$ASM_OPERATION

Estimated amount of time (in minutes)for operation termination

EST_MINUTES

Estimated number of allocation unitsmoved per minute

EST_RATE

Estimated number of remainingallocation units

EST_WORK

Number of allocation units moved sofar

SOFAR

Power allocated to this operationACTUAL

Power requested for this operationPOWERState of operation: QUEUED or RUNNINGSTATE

Type of operation: REBALOPERATION

Disk groupGROUP_NUMBER

DescriptionColumn


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ASM Administration

ASM instance


Files

00100010


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ASM Files

Databasefile

ASM file automatically spread insidedgroupA

CREATE TABLESPACE sample DATAFILE '+dgroupA';

1

23

4

1 2 3 4

Automatic

ASM filemanagement

RMAN

Mandatoryfor

backups


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ASM File Names

ASMfilename

Fullyqualifie

d

Incomplete

with

template

Numeric Alias Aliaswithtemplate

Incomplete

Reference

Single-file

creation

Multiple-file

creation


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ASM File Name Syntax

+///..

+..

+////

+

+()

+////()

1

2

3

4

5

6


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Notes only slide


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ALTER DISKGROUP dgroupAADD TEMPLATE reliable ATTRIBUTES (MIRROR);ALTER DISKGROUP dgroupA DROP TEMPLATE reliable;

ALTER DISKGROUP dgroupADROP FILE '+dgroupA.268.8675309';

ALTER DISKGROUP dgroupAADD DIRECTORY '+dgroupA/mydir';ALTER DISKGROUP dgroupAADD ALIAS '+dgroupA/mydir/datafile.dbf'FOR '+dgroupA.274.38745';ALTER DISKGROUP dgroupADROP ALIAS '+dgroupA/mydir/datafile.dbf';

Template and Alias: Examples


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Retrieving Aliases

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

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

SELECT name

FROM V$ASM_ALIASWHERE parent_index = :alias_id;


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SQL Commands and File Naming

CREATE CONTROLFILE DATABASE sampleRESETLOGS ARCHIVELOGMAXLOGFILES 5 MAXLOGHISTORY 100MAXDATAFILES 10 MAXINSTANCES 2LOGFILE GROUP 1 ('+dgroupA','+dgroupB') SIZE 100M,GROUP 2 ('+dgroupA','+dgroupB') SIZE 100MDATAFILE '+dgroupA.261.12345678' SIZE 100M,'+dgroupA.262.12345678' SIZE 100M;


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DBCA and Storage Options


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Database Instance ParameterChanges

INSTANCE_TYPE = RDBMSLOG_ARCHIVE_FORMATDB_BLOCK_SIZEDB_CREATE_ONLINE_DEST_n

DB_CREATE_FILE_DEST_nDB_RECOVERY_FILE_DESTCONTROL_FILESLOG_ARCHIVE_DEST_nLOG_ARCHIVE_DESTSTANDBY_ARCHIVE_DEST


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Database Instance ParameterChanges

Add at least 600 KB to LARGE_POOL_SIZEAdd the following to SHARED_POOL_SIZE:

SELECT d+l+t DB_SPACEFROM (SELECT SUM(bytes)/(1024*1024*1024) dFROM v$datafile),(SELECT SUM(bytes)/(1024*1024*1024) lFROM v$logfile a, v$log bWHERE a.group#=b.group#),

(SELECT SUM(bytes)/(1024*1024*1024) tFROM v$tempfile WHERE status='ONLINE');

Add at least 16 to PROCESSES

(DB_SPACE/100+2)*#_External_RedOR(DB_SPACE/50+4)*#_Normal_RedOR(DB_SPACE/33+6)*#_High_Red


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Summary

In this lesson, you should have learned howto: Use the DBCA to create an ASM instance Start up and shut down ASM instances Create and maintain ASM disk groups Create database files using ASM


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Practice 5 Overview

This practice covers the following topics: Installing ASMLib. Using the DBCA to create ASM instances. Discovering ASM instances in Database

Control. Creating new ASM disk groups usingDatabase Control.

Generating automatic disk grouprebalancing operations.


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