Recommended Postinstallation Tasks

Recommended Postinstallation Tasks

Oracle recommends that you complete the following tasks as needed after installing Oracle Grid Infrastructure:

• Back Up the root.sh Script
• Tune Semaphore Parameters
• Create a Fast Recovery Area Disk Group

Back Up the root.sh Script

Oracle recommends that you back up the root.sh script after you complete an installation. If you install other products in the same Oracle home directory, then the installer updates the contents of the existing root.sh script during the installation. If you require information contained in the original root.sh script, then you can recover it from the root.sh file copy.

Tune Semaphore Parameters

Refer to the following guidelines only if the default semaphore parameter values are too low to accommodate all Oracle processes:

Note:

Oracle recommends that you refer to the operating system documentation for more information about setting semaphore parameters.

1.      Calculate the minimum total semaphore requirements using the following formula:

2 * sum (process parameters of all database instances on the system) + overhead for background processes + system and other application requirements

2.      Set semmns (total semaphores systemwide) to this total.

3.      Set semmsl (semaphores for each set) to 250.

4.      Set semmni (total semaphores sets) to semmns divided by semmsl, rounded up to the nearest multiple of 1024.

Create a Fast Recovery Area Disk Group

During installation, by default you can create one disk group. If you plan to add an Oracle Database for a standalone server or an Oracle RAC database, then you should create the Fast Recovery Area for database files.

About the Fast Recovery Area and the Fast Recovery Area Disk Group

The Fast Recovery Area is a unified storage location for all Oracle Database files related to recovery. Database administrators can define the DB_RECOVERY_FILE_DEST parameter to the path for the Fast Recovery Area to enable on-disk backups, and rapid recovery of data. Enabling rapid backups for recent data can reduce requests to system administrators to retrieve backup tapes for recovery operations.

When you enable Fast Recovery in the init.ora file, all RMAN backups, archive logs, control file automatic backups, and database copies are written to the Fast Recovery Area. RMAN automatically manages files in the Fast Recovery Area by deleting obsolete backups and archive files no longer required for recovery.

Oracle recommends that you create a Fast Recovery Area disk group. Oracle Clusterware files and Oracle Database files can be placed on the same disk group, and you can also place Fast recovery files in the same disk group. However, Oracle recommends that you create a separate Fast Recovery disk group to reduce storage device contention.

The Fast Recovery Area is enabled by setting DB_RECOVERY_FILE_DEST. The size of the Fast Recovery Area is set with DB_RECOVERY_FILE_DEST_SIZE. As a general rule, the larger the Fast Recovery Area, the more useful it becomes. For ease of use, Oracle recommends that you create a Fast Recovery Area disk group on storage devices that can contain at least three days of recovery information. Ideally, the Fast Recovery Area should be large enough to hold a copy of all of your data files and control files, the online redo logs, and the archived redo log files needed to recover your database using the data file backups kept under your retention policy.

Multiple databases can use the same Fast Recovery Area. For example, assume you have created one Fast Recovery Area disk group on disks with 150 GB of storage, shared by three different databases. You can set the size of the Fast Recovery Area for each database depending on the importance of each database. For example, if database1 is your least important database, database 2 is of greater importance and database 3 is of greatest importance, then you can set different DB_RECOVERY_FILE_DEST_SIZE settings for each database to meet your retention target for each database: 30 GB for database 1, 50 GB for database 2, and 70 GB for database 3.

Creating the Fast Recovery Area Disk Group

To create a Fast recovery file disk group:

1.      Navigate to the Grid home bin directory, and start Oracle ASM Configuration Assistant (ASMCA). For example:

2.  $ cd /u01/app/11.2.0/grid/bin

3.  $ ./asmca

4.      ASMCA opens at the Disk Groups tab. Click Create to create a new disk group

5.      The Create Disk Groups window opens.

In the Disk Group Name field, enter a descriptive name for the Fast Recovery Area group. For example: FRA.

In the Redundancy section, select the level of redundancy you want to use.

In the Select Member Disks field, select eligible disks to be added to the Fast Recovery Area, and click OK.

6.      The Diskgroup Creation window opens to inform you when disk group creation is complete. Click OK.

7.      Click Exit.