Oracle Database Automatic Storage Management-installation Configuration

This brings many benefits, but it also requires learning new concepts, commands, usage, and management tasks. So before you invest in your production system, let's look at what it solves, what it manages, and what it looks like.
Why create it?
The best way to answer this question is to directly trace the source, Bill Bridge-the initial architect of Automatic Storage Management. In Oracle ASM in the title of Oracle Press, Bill provides a link where he discussed the problems encountered when managing Oracle data file placement using a file system of a vendor-specific operating system:
1. for archiving logs and backups, the operating system vendor does not provide a shared disk file system.
2. The logical volume manager hides the file location, making it difficult to manage disk I/O and provide good statistics.
3. When the number of disks exceeds 100, the existing lvm cannot work well.
4. When the database has more than 1000 data files, the operating system and Oracle cannot process the database well.
5. It is difficult to name a large number of data files.
6. Features and file system restrictions vary with the operating system.
7. Users at the operating system level can access Oracle files through standard usage, which Oracle does not know.
Therefore, he began to solve these problems by establishing an Oracle file system. His goal is to provide these features:
1. tightly integrated with Oracle and used with clusters (parallel servers ).
2. automatically use the new storage and manage it as a disk unit or disk group.
3. Supports thousands of disks.
4. The file will not be named and will be hidden in the operating system.
Who needs it?
Now, you can quickly browse the above problems and solutions to help you determine who needs ASM. At first, it was used to process a very large online database. So if it includes your store, you may already be following it, or start executing ASM. If your database is small and there are not many data files, you may need some reason to consider using it.
1. You will be familiar with some new technologies, and should start from building them in your development environment and test them for several months.
2. If you want to get higher performance from your existing Disk Subsystem and get better statistics for predicting disk I/O.
3. If you are using RAC, you need to consider ASM.
Start
ASM is managed by an instance and is very similar to an Oracle database. However, the initial parameters are very limited, and the startup process is much simpler.
A. Set your ORACLE_SID to + ASM1
B. Edit init. ora.
Copy codeThe Code is as follows:
# As opposed to RDBMS for a normal Oracle instance
INSTANCE_TYPE = ASM
# These names will be used in place of datafile names when you create tablespaces
ASM_DISKGROUPS = SEAN, AARON
Processes = 100
# This parameter is platform specific and is the path to the raw disk device
ASM_DISKSTRING = '/dev/cciss/c0d0p1'
# On 11g you shoshould use diagnostic_dest instead of these
Background_dump_dest =/opt/oracle/admin/+ ASM/bdump'

Core_dump_dest =/opt/oracle/admin/+ ASM/cdump'
User_dump_dest =/opt/oracle/admin/+ ASM/udump'

C. Start the ASM instance
Copy codeThe Code is as follows:
$ Sqlplus/as sysdba
SQL> startup

D. Create a disk group
Copy codeThe Code is as follows:
SQL> create diskgroup SEAN disk'/dev/cciss/c0d0p1 ';

E. Create a checklist Space
You may guess that creating a tablespace may slightly change. The default method is as follows:
SQL> create tablespace sean_space datafile '+ SEAN' size 1 GB;
But think about this very good feature. If the init. ora file in your database is set: