Transcript Lesson 12

Automatic Storage Management
Copyright © 2006, Oracle. All rights reserved.
Objectives
After completing this lesson, you should be able to:
• Identify the features 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
12-2
Copyright © 2006, Oracle. All rights reserved.
Automatic Storage Management:
Review
•
•
•
•
•
Portable and high-performance
cluster file system
Manages Oracle database files
Data spread across disks
to balance load
Integrated mirroring across
disks
Solves many storage
management challenges
Application
Database
File
system
Volume
manager
ASM
Operating system
12-3
Copyright © 2006, Oracle. All rights reserved.
ASM General Architecture
DB instance
SID=sales
ASMB
DBW0
FG
ASM
instance
SID=asm
RBAL
ASM disks
ASM disks
ARB0
…
ARBA
ASM disks
ASM disk group 1
12-5
RBAL
ASM disks
ASM disks
ASM disks
ASM disk group 2
Copyright © 2006, Oracle. All rights reserved.
ASM Instance Tasks
The following are tasks that you need to be able to
perform in order to use an ASM instance:
• Create the ASM instance
• Set the initialization parameters
• Start the ASM instance
• Manage the ASM instance
• Shut down the ASM instance
12-7
Copyright © 2006, Oracle. All rights reserved.
Creating an ASM Instance
12-8
Copyright © 2006, Oracle. All rights reserved.
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
12-9
Copyright © 2006, Oracle. All rights reserved.
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
…
12-10
Copyright © 2006, Oracle. All rights reserved.
Starting Up an ASM Instance
$ export ORACLE_SID='+ASM'
$ sqlplus /nolog
SQL> CONNECT / AS sysdba
Connected to an idle instance.
SQL> STARTUP;
ASM instance started
Total System Global Area 147936196
Fixed Size
324548
Variable Size
96468992
Database Buffers
50331648
Redo Buffers
811008
ASM diskgroups mounted
12-11
bytes
bytes
bytes
bytes
bytes
Copyright © 2006, Oracle. All rights reserved.
Accessing an ASM Instance
ASM
instance
AS SYSDBA
All operations
AS SYSOPER
Nondestructive
operations
Disk group
Disk group
Storage system
12-12
Copyright © 2006, Oracle. All rights reserved.
ASM Home Page
12-14
Copyright © 2006, Oracle. All rights reserved.
ASM Performance Page
12-15
Copyright © 2006, Oracle. All rights reserved.
ASM Configuration Page
12-16
Copyright © 2006, Oracle. All rights reserved.
Shutting Down an ASM Instance
Database instance A
Database instance B
2
ASM instance
3
SHUTDOWN NORMAL
1
12-17
1
Copyright © 2006, Oracle. All rights reserved.
DBCA and Storage Options
12-18
Copyright © 2006, Oracle. All rights reserved.
ASM Storage: Concepts
ASM
disk group
Database
Tablespace
ASM file
Data file
Segment
Extent
Oracle data
block
12-19
ASM disk
File system
file
or
raw device
Allocation unit
(AU)
Physical
block
Copyright © 2006, Oracle. All rights reserved.
ASM Disk Groups
•
•
•
•
•
A pool of disks managed as
a logical unit
Partitions total disk space into
uniform sized units
Spreads each file evenly
across all disks
Uses coarse- or fine-grain
striping on the basis of file
type
Administers disk groups, not
files
ASM
instance
Disk group
12-20
Copyright © 2006, Oracle. All rights reserved.
Failure Group
Controller 1
Controller 2
Controller 3
6
5
4
3
2
1
1
1
7
7
7
13
13
13
Failure group 1
1
1
1
7
7
7
13
13
13
Failure group 2
Disk group A
12-21
Copyright © 2006, Oracle. All rights reserved.
1
1
1
7
7
7
13
13
13
Failure group 3
Disk Group Mirroring
•
•
•
•
Mirror at AU level
Mix primary and mirror
AUs on each disk
External redundancy:
Defers to hardware
mirroring
Normal redundancy:
– Two-way mirroring
– At least two failure groups
•
High redundancy:
– Three-way mirroring
– At least three failure groups
12-22
Copyright © 2006, Oracle. All rights reserved.
Disk Group Dynamic Rebalancing
•
•
•
•
•
12-23
Automatic online
rebalance whenever
storage configuration
changes
Only move data
proportional to
storage added
No need for manual
I/O tuning
Online migration to
new storage
Configurable load
on system using ASM_POWER_LIMIT
Copyright © 2006, Oracle. All rights reserved.
Managing Disk Groups
CREATE DISKGROUP
ASM
instance
DROP DISKGROUP
Database
instance
ALTER DISKGROUP
12-24
Copyright © 2006, Oracle. All rights reserved.
ASM Administration Page
12-25
Copyright © 2006, Oracle. All rights reserved.
Create Disk Group Page
12-26
Copyright © 2006, Oracle. All rights reserved.
Creating and Dropping 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;
12-27
Copyright © 2006, Oracle. All rights reserved.
Adding Disks to Disk Groups
ALTER DISKGROUP dgroupA ADD
'/dev/rdsk/c0t4d0s2' NAME
'/dev/rdsk/c0t5d0s2' NAME
'/dev/rdsk/c0t6d0s2' NAME
'/dev/rdsk/c0t7d0s2' NAME
DISK
A5,
A6,
A7,
A8;
ALTER DISKGROUP dgroupA ADD DISK '/devices/A*';
Disk formatting
Disk group rebalancing
12-28
Copyright © 2006, Oracle. All rights reserved.
Miscellaneous ALTER Commands
Remove a disk from dgroupA:
ALTER DISKGROUP dgroupA DROP DISK A5;
Add and drop a disk in a single command:
ALTER DISKGROUP dgroupA
DROP DISK A6
ADD FAILGROUP fred
DISK '/dev/rdsk/c0t8d0s2' NAME A9;
Cancel a disk drop operation:
ALTER DISKGROUP dgroupA UNDROP DISKS;
12-30
Copyright © 2006, Oracle. All rights reserved.
ASM Files
CREATE TABLESPACE sample DATAFILE '+dgroupA';
Database file
RMAN
1
Automatic
ASM file
creation
1
2
3
4
2
3
4
ASM file automatically spread inside disk group dgroupA
12-32
Copyright © 2006, Oracle. All rights reserved.
ASMCMD Utility
SQL> CREATE TABLESPACE tbsasm DATAFILE '+DGROUP1' SIZE 100M;
Tablespace created.
SQL> CREATE TABLESPACE hrapps DATAFILE '+DGROUP1' SIZE 10M;
Tablespace created.
$ asmcmd
ASMCMD> ls -l DGROUP1/ORCL/DATAFILE
Type
Redund Striped Time
DATAFILE MIRROR COARSE
OCT 05 21:00:00
DATAFILE MIRROR COARSE
OCT 05 21:00:00
ASMCMD>
12-33
Sys
Y
Y
Copyright © 2006, Oracle. All rights reserved.
Name
HRAPPS.257.570923611
TBSASM.256.570922917
Migrating Your Database to ASM Storage
1. Shut down your database cleanly.
2. Shut down 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";
12-34
Copyright © 2006, Oracle. All rights reserved.
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
12-36
Copyright © 2006, Oracle. All rights reserved.
Practice Overview:
Using Automatic Storage Management
This practice covers the following topics:
• Creating and starting an ASM instance
• Creating and using ASM disk groups
• Migrating a tablespace to ASM storage
12-37
Copyright © 2006, Oracle. All rights reserved.