Remote DBA

Oracle Creating the ASM Instance Manually (on Windows)

Oracle Tips by Burleson Consulting

This is an excerpt from "Oracle 10g New Features for Administrators" by Ahmed Baraka.

1. If CSS service is not there, create it by executing the following bat file:

<orahome>\bin\localconfig add

2. Building the ASM Candidate "disks": for testing or development purpose

ASMTOOL -create c:\asmdisks\asmdisk1 250

3. Create a pfile with the name "init+ASM.ora" in the folder <ORACLE_HOME>\database. Insert the following parameters in the file:

INSTANCE_TYPE=ASM
_ASM_ALLOW_ONLY_RAW_DISKS = FALSE
DB_UNIQUE_NAME = +ASM
ASM_DISKSTRING ='C:\asmdisks\*'
LARGE_POOL_SIZE = 16M
BACKGROUND_DUMP_DEST =
'D:\oracle\admin\+ASM\bdump'
USER_DUMP_DEST = 'D:\oracle\admin\+ASM\udump'
CORE_DUMP_DEST = 'D:\oracle\admin\+ASM\cdump'

Note: The undocumented parameter_ASM_ALLOW_ONLY_RAW_DISKS is used to make the instance recognize virtual disks created in previous step.

Of course, in a production database, this parameter is not used.

4. Create the ASM instance service:

ORADIM -NEW -ASMSID +ASM -STARTMODE auto

5. Startup the instance

SET ORACLE_SID=+ASM
C:\> SQLPLUS / AS SYSDBA
SQL> STARTUP FORCE
SQL> SELECT PATH, MOUNT_STATUS FROM V$ASM_DISK;

Creating the ASM Instance Manually (on Unix)

Steps here assumes the following:

� Red Hat Enterprise Server 3 installed and patched to kernel version 2.4.21-15

� Oracle version 10.1.0.3 (Enterprise Edition) installed as per instructions here.

1. After logging as root, create disks Create physical files:

dd if=/dev/zero of=/asmdisks/disk1 bs=1024k
count=250

Map loopback devices to the files:

/sbin/losetup /dev/loop1 /asmdisks/disk1

2. Download oracleasm utility from Oracle site.

3. Install the utility files as follows:

rpm -ivh *.rpm

4. With the basic libraries installed, you need to configure them so that they get re-loaded at every server reboot:

[root@koala howardjr]# /etc/init.d/oracleasm
configure
Default user to own the driver interface []:
oracle
Default group to own the driver interface []:
oinstall
Start Oracle ASM library driver on boot (y/n)
[n]: y
Fix permissions of Oracle ASM disks on boot
(y/n) [y]: y

5. Writing the ASM Disk Header information:

/etc/init.d/oracleasm createdisk ASMD1
/dev/loop1
Marking disk "/dev/loop1" as an ASM disk [ OK ]

6. After logging on as Oracle user now, under the $ORACLE _HOME/dbs directory, create the file "init+ASM.ora" and type the following in it:

INSTANCE_TYPE = ASM
DB_UNIQUE_NAME = +ASM
LARGE_POOL_SIZE = 16M
ASM_DISKSTRING = 'ORCL:*'
[oracle@koala dbs]$ export ORACLE_SID=+ASM
[oracle@koala dbs]$ sqlplus / as sysdba
SQL> startup
SQL> select path from v$asm_disk;

Starting and Shutting Down an ASM Instance

� When starting an ASM instance, you can use the STARTUP command with the NOMOUNT, MOUNT, RESTRICT and FORCE options. You cannot use the STARTUP OPEN syntax.

� If you either start up your ASM instance with the STARTUP RESTRICT command or issue the ALTER SYSTEM ENABLE RESTRICTED SESSION command in a normal ASM instance, Oracle database instances cannot connect to the ASM instance.

� If you shut down an ASM instance, all Oracle databases currently connected to it will also shut down.