Tuesday, 30 August 2016

ORACLE RAC BEGINNERS GUIDE

ORACLE RAC


1)   ARCHITECTURE

1.1)         WHAT IS IT
Oracle RAC allows multiple computers to run Oracle RDBMS software simultaneously while accessing a single database, thus providing a clustered database.
In a non-RAC Oracle database, a single instance accesses a single database. The database consists of a collection of data files, control files, and redo logs located on disk. The instance comprises the collection of Oracle-related memory and operating system processes that run on a computer system.
In an Oracle RAC environment, two or more computers (each with an instance) concurrently access a single database. This allows an application or user to connect to either computer and have access to a single coordinated set of data.

1.2)         ARCHITECTURAL   OVERVIEW
THE ORACLE 10G RAC ARCHITECTURE



From the point of view of the installation, the main architecture of the RAC environment includes the following:
* Nodes or Servers
* Private Interconnect
* Vendor Supplied Cluster Manager or Cluster Software (Optional)
* Oracle provided Cluster Ready Services
* Shared Storage Subsystem
* Raw Partitions or Cluster File System or Network Attached Storage (NAS) or Automatic Storage Management (ASM)
* Public Network Connection
* Oracle Database software with RAC option
* Filesystem
1.2.1) Nodes or Hosts
The nodes or servers are the main platforms on which the Oracle RAC database is installed. The Cluster nodes range from a high-end powerful Sun Fire 15K to a low-end Linux server. They can also range from a mainframe grade IBM zSeries server to the emerging blade-server technologies such as IBM BladeCenter or Egenera. First, the appropriate operating system needs to be installed on the nodes. It is also important to choose the appropriate number of nodes while setting up the node operating environment.
1.2.2) Private Interconnect
The private interconnect is the physical construct that allows inter-node communication. It can be a simple crossover cable with UDP or it can be a proprietary interconnect with specialized proprietary communications protocol. When setting up more than 2- nodes, a switch is usually needed. This provides the maximum performance for RAC, which relies on inter-process communication between the instances for cache-fusion implementation.
1.2.3) Clusterware
Oracle Clusterware is software that enables servers to operate together as if they are one server. Each server looks like any standalone server.
Creating clusters involves installation of the cluster software on all nodes in the proposed cluster, as well as checking the configuration. The necessary tests need to be performed to verify the validity of the cluster. At the same time, the necessary software that controls the private interconnect is also installed and configured. With the availability of Oracle provided Cluster Ready Services (CRS), one can achieve a uniform and standard cluster platform. CRS is more than just cluster software, but it extends the high availability services in the cluster.
1.2.4) Shared Storage
The storage system provides an external common disk system accessible by all nodes of the cluster. The connection from the nodes to the disk sub-system is usually through a fiber switch or a SCSI connection. Once the storage volumes are presented to the hosts in the cluster, usually with the help of the logical volume manager, one can create volumes of suitable size for use in the RAC database. With the introduction of ASM methodology, the shared storage structures can be managed very easily. Once the disk groups are created with input of the disk devices, the ASM instances on each of the node in the cluster provide the shared storage resources to create the Database Files. The preparation of storage structures has been covered extensively in Chapter 5, Preparing Shared Storage.
1.2.5) Public Network
The clustered servers or hosts need to have public network connectivity so that client machines in the network can access the resources on the RAC system.
1.2.6) Virtual IP Address for CRS
Oracle 10g release supports the concept of Service, which can be assigned the Virtual IP address, and which float among the specified nodes. By creating the Virtual IP address(A virtual IP address (VIP or VIPA) is an IP address that is not connected to a specific computer or network interface card (NIC) on a computer. Incoming packets are sent to the VIP address, but they are redirected to physical network interfaces.VIPs are mostly used for connection redundancy; a VIP address may still be available if a computer or NIC fails because an alternative computer or NIC replies to connections.) and Virtual Host names, the applications get a sense of transparency in their connection to the RAC database service.
1.2.7) File systems

A regular single-instance database has three basic types of files: database software and dump files; datafiles, spfile, control files and log files, often referred to as "database files"; and it may have recovery files, if using RMAN. A RAC database has an additional type of file referred to as "CRS files". These consist of the Oracle Cluster Registry (OCR) and the voting disk. An Oracle RAC database can have up to
100 instances.

Depending on your platform, you can use the following file storage
options for Oracle RAC
■ ASM, which Oracle recommends
■ Oracle Cluster File System (OCFS), which is available for Linux and Windows
platforms, or a third-party cluster file system that is certified for Oracle RAC
■ A network file system
■ Raw devices

Oracle RAC databases differ architecturally from Oracle RACsingle-instance Oracle
databases in that each Oracle RAC database instance also has:

■ At least one additional thread of redo for each instance
■ An instance-specific undo tablespace



1.3)            ARCHITECHTURAL COMPONENTS

1.3.1) Private interconnect components

Oracle recommends that you configure a redundant interconnect to prevent the
interconnect from being a single point of failure. Oracle also recommends that you use
User Datagram Protocol (UDP) on a Gigabit Ethernet for your cluster interconnect.
Crossover cables are not supported for use with Oracle Clusterware or Oracle RAC
databases. All nodes in an Oracle RAC environment must connect to a Local Area Network(LAN) to enable users and applications to access the database. . Users can access an Oracle RAC database using a client-server configuration or through one or more middle tiers, with or without connection pooling. Users can be DBAs, developers, application users, power users, such as data miners who create their own searches, and so on. Most public networks typically use TCP/IP, but you can use any supported hardware and software combination. Oracle RAC database instances can be accessed through a database’s defined, default IP address and through VIP addresses.

In addition to the node’s host name and IP address, you must also assign a virtual host
name and an IP address to each node. The virtual host name or VIP should be used to
connect to the database instance. For example, you might enter the virtual host name
CRM in the address list of the tnsnames.ora file.

1.3.2) Oracle Clusterware components

The Oracle Clusterware requires two clusterware components: a voting
disk to record node membership information.Oracle RAC uses the voting disk to determine which instances are members of a cluster. The voting disk must reside on shared disk and the Oracle Cluster Registry (OCR) to record cluster configuration information. Maintains cluster configuration information as well as configuration information about any cluster database within the cluster.The OCR also manages information about processes that Oracle Clusterware controls. The voting disk and the OCR must reside on shared storage. The Oracle Clusterware can multiplex
the OCR and the voting disks and Oracle recommends that you use this feature to ensure cluster high availability.

The following list describes the functions of some of the major Oracle Clusterware components

Cluster Synchronization Services (CSS)—Manages the cluster configuration by
controlling which nodes are members of the cluster and by notifying members
when a node joins or leaves the cluster. If you are using third-party clusterware,
then the css process interfaces with your clusterware to manage node
membership information.
■ Cluster Ready Services (CRS)—The primary program for managing high
availability operations within a cluster. Anything that the crs process manages is
known as a cluster resource which could be a database, an instance, a service, a
Listener, a virtual IP (VIP) address, an application process, and so on. The crs
process manages cluster resources based on the resource’s configuration
information that is stored in the OCR. This includes start, stop, monitor and
failover operations. The crs process generates events when a resource status
changes. When you have installed Oracle RAC, crs monitors the Oracle instance,
Listener, and so on, and automatically restarts these components when a failure
occurs. By default, the crs process makes five attempts to restart a resource and
then does not make further restart attempts if the resource does not restart.
■ Event Management (EVM)—A background process that publishes events that
crs creates.
■ Oracle Notification Service (ONS)—A publish and subscribe service for communicating Fast Application Notification (FAN- FAN is a notification mechanism that Oracle RAC uses to notify other processes about configuration and service level information such as includes service status changes, such as UP or DOWN events) events.
■ RACG—Extends clusterware to support Oracle-specific requirements and
complex resources. Runs server callout scripts when FAN events occur.
■ Process Monitor Daemon (OPROCD)—This background process is locked in memory to monitor the cluster and provide I/O fencing. OPROCD performs its check, stops running, and if the wake up is beyond the expected time, then OPROCD resets the processor and reboots the node. An OPROCD failure results in Oracle Clusterware restarting the node





2)   REQUIREMENTS

2.1) MINIMUM REQUIREMENTS

Production and Test (RAC)
Oracle Enterprise Linux 5 update 2
Oracle Clusterware (Grid) Oracle Clusterware Release 2 (10.2.0.1.0)
Oracle ASM 11.2.0.2
Oracle Database  EE Oracle Database 10g Release 2 (10.2.0.1.0)

Development (Single Instance)
Oracle Enterprise Linux 5 update 2
Oracle ASM -- Grid Infrastructure 
Oracle Database EE Oracle Database 10g Release 2 (10.2.0.1.0)


2.2) TOOLS FOR INSTALLING,CONFIGURING AND MANAGING ORACLE RAC

The following is a description of the tools used for installing, configuring, and
managing an Oracle RAC database:

■ Oracle Universal Installer (OUI)–OUI installs the Oracle Clusterware and the
Oracle Database software with Oracle RAC. After you configure the nodes that
you want to use in your cluster, OUI installs the Oracle software on the specified
nodes using a network connection.

■ Cluster Verification Utility (CVU)–The CVU is a command-line tool that you can
use to verify a range of cluster and Oracle RAC components such as shared
storage devices, networking configurations, system requirements, and Oracle
Clusterware, as well as operating system groups and users. You can use the CVU
for preinstallation as well as postinstallation checks of your cluster environment.
The CVU is especially useful during preinstallation and during installation of
Oracle Clusterware and Oracle RAC components. OUI runs the CVU after the
Oracle Clusterware installation to verify your environment.

■ Oracle Enterprise Manager –Oracle Enterprise Manager has both the Database
Control and Grid Control graphical user interfaces (GUIs) for managing singleinstance and Oracle RAC environments.
■ Server Control (SRVCTL)–SRVCTL is a command-line interface that you can use
to manage an Oracle RAC database from a single point. You can use SRVCTL to
start and stop the database and instances, and to delete or move instances and
services. You can also use SRVCTL to add services and manage configuration
information. You use SVRCTL to start and stop a group of applications that




2.3) CHECKING REQUIREMENTS

Before you begin your installation, you should check to make sure that your system
meets the requirements for Oracle Real Application Clusters (RAC). The requirements
can be grouped into the following three categories:
■ Checking the Hardware Requirements
■ Network Requirements
■ Verifying the Installed Operating System and Software Requirements

2.3.1) Checking the Hardware Requirements

Each node that you want to make part of your Oracle Clusterware, or Oracle
Clusterware and Oracle RAC installation, must satisfy the minimum hardware
requirements of the software. These hardware requirements can be categorized as
follows:
■ Physical memory (at least 1 gigabyte (GB) of RAM)
■ Swap space (at least 2 GB of available swap space)
■ Temporary space (at least 400 megabytes (MB))
■ Processor type (CPU) that is certified with the version of the Oracle software being installed

These Oracle Clusterware components require the following additional disk space:
■ Two Oracle Clusterware Registry files, 256 MB each, or 512 MB total disk space
■ Three voting disk files, 256 MB each, or 768 MB total disk space


2.3.2) Network Requirements

The interconnect used by Oracle RAC is the same interconnect that Oracle Clusterware uses. This interconnect should be a private interconnect, meaning it is not be accessible by nodes that are not members of the cluster.

When you configure the network for Oracle RAC and Oracle Clusterware, each node
in the cluster must meet the following requirements:

■ Each node needs at least two network interface cards, or network adapters. One
adapter is for the public network and the other adapter is for the private network
used by the interconnect.

■ For the private network, the interconnect must support the user datagram protocol
(UDP) using high-speed network adapters and switches that support TCP/IP
(Gigabit Ethernet or better recommended).

■ You must have at least three IP addresses available for each node:
1. An IP address with an associated host name (or network name) for the public
interface.
2. A private IP address with a host name for each private interface.
3. One virtual IP address with an associated network name.

Public and Private interface names must be the same for all nodes


2.3.3) Verifying the Installed Operating System and Software Requirements

Operating system requirements

These requirements can include any of the following:
■ The operating system version
■ The kernel version of the operating system
■ Installed packages, patches, or patch sets
■ Installed compilers and drivers
■ Web browser type and version
■ Additional application software requirements

Operating system users and groups

The following operating system groups are used when installing Oracle software:
■ The OSDBA group (typically, dba) for Oracle Database authentication
■ The Oracle Inventory group (typically, oinstall) for all installations
■ (Optional) A separate OSASM group (for example, asm) for Automatic Storage

The following operating system users are required for all installations:
■ A user that owns the Oracle software (typically, oracle)
■ An unprivileged user (for example, the nobody user on Linux systems)

About Setting the Time on Both Nodes

Before starting the installation, ensure that the date and time settings on both nodes
are set as closely as possible to the same date and time. Oracle strongly recommends
using the Network Time Protocol (NTP) feature of most operating systems for this
purpose. All the nodes in your cluster should use the same reference NTP server.

About Deciding on a Shared Storage Solution

Each node in a cluster requires external shared disks for storing the Oracle
Clusterware (Oracle Cluster Registry and voting disk) files, and Oracle Database files.
The supported types of shared storage depend upon the platform you are using, for
example:
■ A supported cluster file system, such as OCFS2 for Linux, OCFS for Microsoft
Windows, or General Parallel File System (GPFS) on IBM platforms
■ Network file system (NFS), which is not supported on AIX Based Systems, Linux
on POWER, or on IBM zSeries Based Linux
■ Shared disk partitions consisting of block devices. Block devices are disk partitions
that are mounted using the Linux file system. Oracle Clusterware and Oracle RAC
write to these partitions directly.
■ Automatic Storage Management for Oracle Database files (strongly recommended)

Note: Oracle Clusterware files cannot be stored in ASM.it is only used to store the database files

Before you install Oracle Clusterware, you will need to configure 5 shared disk
partitions:
■ 1 partition which is 280 MB in size for storing the Oracle Cluster Registry (OCR)
■ 1 partition which is 280 MB in size for storing a duplicate OCR file on a different
disk, referred to as the OCR mirror
■ 3 partitions which are 280 MB in size, 1 for each voting disk location

About Choosing an Oracle Base Directory

Oracle Universal Installer (OUI) creates the Oracle base directory for you in the
location you specify. The Oracle base directory (ORACLE_BASE) acts as a top-level
directory for Oracle software installations. The file system that you use for the Oracle base directory must have at least 7 GB of available disk space for installing the Oracle Database software. The path to the Oracle base directory must be the same on all nodes. install Oracle RAC and ASM in separate home directories.


About Choosing an Oracle Clusterware Home Directory

OUI installs Oracle Clusterware into a directory structure referred to as CRS_home.
This home is separate from the home directories for other Oracle products installed on
the same server. OUI creates the CRS home directory for you. Before you start the
installation, you must have sufficient disk space on a file system for the Oracle
Clusterware directory, and the CRS home directory you choose should be owned by
the installation owner of Oracle Clusterware.

The file system that you use for the CRS home directory must have at least 2 GB of
available disk space. The path to the CRS home directory must be the same on all
nodes.


3)   INSTALLATION

3.1) INSTALLING AND CONFIGURING ORACLE CLUSTERWARE AND ORACLE RAC

This chapter includes the following sections:
■ Preparing the Oracle Media Installation File
■ Installing Oracle Clusterware
■ Configuring Automatic Storage Management in an ASM Home Directory
■ Installing the Oracle Database Software and Creating a Cluster Database
■ Performing Postinstallation Tasks

3.1.1) Preparing the Oracle Media Installation File

OUI installs Oracle Clusterware into a directory structure that is referred to as CRS_home. the standard Oracle Database 10g software installation
process installs the Oracle RAC option when OUI recognizes that you are performing
the installation on a cluster. OUI installs Oracle RAC into a directory structure that is
referred to as Oracle_home.

3.1.2) Installing Oracle Clusterware

The following topics describe the process of installing Oracle Clusterware:
■ Configuring the Operating System Environment
■ Verifying the Configuration Using the Cluster Verification Utility
■ Using Oracle Universal Installer to Install Oracle Clusterware
■ Completing the Oracle Clusterware Configuration

3.1.2.1) Configuring the Operating System Environment

You run OUI from the oracle user account. Before you start OUI you must configure
the environment of the oracle user. You must set the ORACLE_BASE environment
variables to the directory in which you want the Oracle central inventory files located. Prior to installing the Oracle Database software and creating an Oracle database, you
should also set the ORACLE_HOME environment variable to the location in which you
want to install the Oracle Database software

To modify the user environment prior to installing Oracle Clusterware on Red
Hat Linux:

1. As the oracle user, execute the following commands:
[oracle]$ unset ORACLE_HOME
[oracle]$ unset ORACLE_SID
[oracle]$ unset ORACLE_BASE
[oracle]$ export ORACLE_BASE=/opt/oracle/11gR1
2. Verify the changes have been made by executing the following commands:
[oracle]$ echo $ORACLE_SID
[oracle]$ echo $ORACLE_HOME
[oracle]$ echo $ORACLE_BASE
/opt/oracle/11gR1

To modify the user environment prior to installing Oracle Database on Red Hat
Linux:

1. As the oracle user, modify the user profile in the /home/oracle directory on
both nodes using the following commands:
[oracle] $ cd $HOME
[oracle] $ vi .bash_profile
Add the following lines at the end of the file:
export ORACLE_SID=sales
export ORACLE_BASE=/opt/oracle/11gR1
export ORACLE_HOME=/opt/oracle/11gR1/db
2. Read and implement the changes made to the .bash_profile file:
source .bash_profile
3. Verify the changes have been made by executing the following commands:
[oracle]$ echo $ORACLE_SID sales
[oracle]$ echo $ORACLE_HOME /opt/oracle/11gR1/db
[oracle]$ echo $ORACLE_BASE /opt/oracle/11gR1

3.1.2.2) Verifying the Configuration Using the Cluster Verification Utility

If you have not configured your nodes, network, and operating system correctly, your
installation of the Oracle Clusterware or Oracle Database 11g software will not
complete successfully

To verify your hardware and operating system setup:
1. As the oracle user, change directories to the staging directory for the Oracle
Clusterware software
[oracle] $ cd /staging_area
2. Run the runcluvfy.sh script, as shown in the following example, where
docrac1 and docrac2 are the name of the nodes in your cluster:
[oracle] $ ./runcluvfy.sh stage -pre crsinst -n docrac1,docrac2 -verbose

3.1.2.3) Using Oracle Universal Installer to Install Oracle Clusterware
As the oracle user on the docrac1 node, install Oracle Clusterware

To install Oracle Clusterware:
1. Use the following command to start OUI, where staging_area is the location of
the staging area on disk, or the location of the mounted installation disk:
cd /staging_area/Disk1
./runInstaller
The Select a Product to Install window appears.
2. Select Oracle Clusterware from the list, then click Next.


3.Change the path for the inventory location, if required. Select oinstall for the
operating system group name. Click Next.
The path displayed for the inventory directory should be the oraInventory
subdirectory of your Oracle base directory. For example, if you set the
ORACLE_BASE environment variable to /opt/oracle/11gR1 before starting
OUI, then the path displayed is /opt/oracle/11gR1/oraInventory.



4. Accept the default value for the Name field, which is the name of the Oracle home
directory for this product. For the Path field, click Browse. In the Choose Directory
window Go up the path until you reach the root directory (/), click
/u01/app/crs, then click Choose Directory.
After you have selected the path, click Next. The next window, Product-Specific
Prerequisite Checks, appears after a short period of time.
5. When you see the message "Check complete. The overall result of this check is:
Passed", as shown in the following screenshot, click Next.


6. Change the default cluster name to a name that is unique throughout your entire
enterprise network. For example, you might choose a name that is based on the
node names' common prefix.
When you have finished removing the domain name in the "Modify a node in the
existing cluster" window, click OK.
7. When you are returned to the Specify Cluster Configuration window, click Add.
8. In the "Add a new node to the existing cluster" dialog window, enter the second
node's public name (docrac2.us.oracle.com), private name
(docrac2-priv), and virtual IP name (docrac2-vip.us.oracle.com), and
then click OK.
The Specify Cluster Configuration window now displays both nodes in the
Cluster Nodes.


9. Verify eth0 and eth1 are configured correctly (proper subnet and interface type
displayed), then click Next.
The Specify Oracle Cluster Registry (OCR) Location window appears.
10. Select Normal Redundancy for the OCR Configuration. You will be prompted for two file locations. In the Specify OCR Location field, enter the name of the device
configured for the first OCR file, for example, /dev/sda1.
In the Specify OCR Mirror Location field, enter the name of the device configured
for the OCR mirror file, for example /dev/sdb1. When finished, click Next.
During installation, the OCR data will be written to the specified locations.



11. Select Normal Redundancy for the voting disk location. You will be prompted for
three file locations. For the Voting Disk Location, enter the name of the device
configured for the first voting disk file, for example, /dev/sda2. Repeat this
process for the other two Voting Disk Location fields.


12. Review the contents of the Summary window and then click Install.
OUI displays a progress indicator during the installation process.
13. During the installation process, the Execute Configuration Scripts window
appears. Do not click OK until you have run the scripts.



The Execute Configuration Scripts window shows configuration scripts, and the
path where the configuration scripts are located. Run the scripts on all nodes as
directed, in the order shown. For example, on Red Hat Linux you perform the
following steps (note that for clarity, the examples show the current user, node and
directory in the prompt):
a. As the oracle user on docrac1, open a terminal window, and enter the
following commands:
[oracle@docrac1 oracle]$ cd /opt/oracle/11gR1/oraInventory
[oracle@docrac1 oraInventory]$ su
b. Enter the password for the root user, and then enter the following command
to run the first script on docrac1:
[root@docrac1 oraInventory]# ./orainstRoot.sh
c. After the orainstRoot.sh script finishes on docrac1, open another
terminal window, and as the oracle user, enter the following commands:
[oracle@docrac1 oracle]$ ssh docrac2
[oracle@docrac2 oracle]$ cd /opt/oracle/11gR1/oraInventory
[oracle@docrac2 oraInventory]$ su
d. Enter the password for the root user, and then enter the following command
to run the first script on docrac2:
[root@docrac2 oraInventory]# ./orainstRoot.sh
e. After the orainstRoot.sh script finishes on docrac2, go to the terminal
window you opened in Step 15a. As the root user on docrac1, enter the
following commands to run the second script, root.sh:
[root@docrac1 oraInventory]# cd /u01/app/crs
[root@docrac1 crs]# ./root.sh

At the completion of this script, the following message is displayed:
f. After the root.sh script finishes on docrac1, go to the terminal window
you opened in Step 15c. As the root user on docrac2, enter the following
commands:
[root@docrac2 oraInventory]# cd /u01/app/crs
[root@docrac2 crs]# ./root.sh
After the root.sh script completes, return to the OUI window where the Installer
prompted you to run the orainstRoot.sh and root.sh scripts. Click OK.
The Configuration Assistants window appears. When the configuration assistants
finish, OUI displays the End of Installation window.
14. Click Exit to complete the installation process, then Yes to confirm you want to
exit the installer.
If you encounter any problems, refer to the configuration log for information. The
path to the configuration log is displayed on the Configuration Assistants window.

3.1.2.4) Completing the Oracle Clusterware Configuration

To complete the Oracle Clusterware configuration on Red Hat Linux:
1. As the oracle user on docrac1, check the status of the Oracle Clusterware
targets by entering the following command:
/u01/app/crs/bin/crs_stat -t
This command provides output showing if all the important cluster services, such
as gsd, ons, and vip, are running on the nodes of your cluster.



3.1.3) Configuring Automatic Storage Management in an ASM Home Directory

This section explains how to install the ASM software in its own home directory.
Installing ASM in its own home directory enables you to keep the ASM home separate
from the database home directory (Oracle_home).

3.1.3.1) To install ASM in a home directory separate from the home directory used by Oracle Database:

1. Use the following commands to start OUI, where staging_area is the location
of the staging area on disk, or the location of the mounted installation disk:
cd /staging_area/database
./runInstaller
When you start Oracle Universal Installer, the Select a Product to Install window
appears.
2.       Select Oracle Database 11g from the list, then click Next.

The Select Installation Type window appears.
3. Select either Enterprise Edition or Standard Edition and then click Next.
4. In the Specify Home Details window, specify a name for the ASM home directory,
for example, OraASM11g_home. Select a directory that is a subdirectory of your
Oracle Base directory, for example, /opt/oracle/11gR1/asm. Click Browse to
change the directory in which ASM will be installed.


After you have specified the ASM home directory, click Next.
The Specify Hardware Cluster Installation Mode window appears.
5. Click Select All to select all nodes for installation, and then click Next.
If your Oracle Clusterware installation was successful, then the Specify Hardware
Cluster Installation Mode window lists the nodes that you identified for your
cluster, such as docrac1 and docrac2.
After you click Next, the Product-Specific Prerequisites Checks window appears.
6. When you see the message "Check complete. The overall result of this check is:
Passed", as shown in the following screenshot, click Next.


The Select Configuration Option window appears.
7. Select the Configure Automatic Storage Management (ASM) option to install and
configure ASM. The ASM instance is managed by a privileged role called SYSASM,
which grants full access to ASM disk groups.
Enter a password for the SYSASM user account. The passwords should be at least 8
characters in length and include at least one alphabetic and one numeric character.
Confirm the password by typing it in again in the Confirm ASM SYS Password
field.


When finished, click Next.
The Configure Automatic Storage Management window appears.
8. In the Configure Automatic Storage Management window, the Disk Group Name
defaults to DATA. You can enter a new name for the disk group, or use the default
name.
Check with your system administrator to determine if the disks used by ASM are
mirrored at the storage level. If so, select External for the redundancy. If the disks
are not mirrored at the storage level, then choose Normal for the redundancy.
9. At the bottom right of the Add Disks section, click Change Disk Discovery Path
to select any devices that will be used by ASM but are not listed.
In the Change Disk Discovery Path window, enter a string to use to search for
devices that ASM will use, such as /dev/sd*, and then click OK.


You are returned to the Configure Automatic Storage Management window.
10. Select the disks to be used by ASM, for example, /dev/sdd and /dev/sde


After you have finished selecting the disks to be used by ASM, click Next. The
Privileged Operating Systems Groups window appears.
11. Select the name of the operating system group you created in the previous chapter
for the OSDBA group, the OSASM group, and the database operator group. If you
choose to create only the dba group, then you can use that group for all three
privileged groups. If you created a separate asm group, then use that value for the
OSASM group.


After you have supplied values for the privileged groups, click Next. The Oracle
Configuration Manager Registration window appears.
12. The Oracle Configuration Manager Registration window enables you to configure
the credentials used for connecting to OracleMetaLink. You can provide this
information now, or configure it after the database has been installed. Click Next
to continue.
OUI displays the Summary window.
13. Review the information displayed in the Summary window. If any of the
information appears incorrect, then click Back to return to a previous window and
change it. When you are ready to proceed, click Install.
OUI displays a progress window indicating that the installation has started.
14. The installation takes several minutes to complete. During this time, OUI
configures ASM on the specified nodes, and then configures a listener on each
node.
After ASM has been installed, OUI runs the Configuration Assistants. When the
assistants have finished successfully, click Next to continue.
The Execute Configuration Scripts window appears.
15. Run the scripts as instructed in the Execute Configuration scripts window. For the
installation demonstrated in this guide, only one script, root.sh, must be run,
and it must be run on both nodes.


The following steps demonstrate how to complete this task on a Linux system
(note that for clarity, the examples show the user, node name, and directory in the
prompt):
a. Open a terminal window. As the oracle user on docrac1, change directories
to the ASM home directory, and then switch to the root user:
[oracle@docrac1 oracle]$ cd /opt/oracle/11gR1/asm
[oracle@docrac1 oracle]$ su
b. Enter the password for the root user, and then run the script specified in the
Execute Configuration scripts window:
[root@docrac1 oracle]# ./root.sh

c. As the root.sh script runs, it prompts you for the path to the local bin
directory. The information displayed in the brackets is the information it has
obtained from your system configuration. Press the Enter key each time you
are prompted for input to accept the default choices.
d. After the script has completed, the prompt appears. Open another terminal
window, and enter the following commands:
[oracle@docrac1 oracle]$ ssh docrac2
Enter the passphrase for key ’/home/oracle/.ssh/id_rsa’:
[oracle@docrac2 oracle]$ cd /opt/oracle/11gR1/asm
[oracle@docrac2 asm]$ su
Password:
e. Enter the password for the root user, and then run the script specified in the
Execute Configuration scripts window:
[root@docrac2 asm]# ./root.sh
f. Accept all default choices by pressing the Enter key.
g. After you finish executing the script on all nodes, return to the Execute
Configuration Scripts window and click OK to continue.
OUI displays the End of Installation window.
16. Review the information in the End of Installation window. The Web addresses
displayed are not used in this guide, but may be needed for your business
applications.
17. Click Exit, and then click Yes to verify that you want to exit the installation.

3.1.3.2) Verifying Your ASM Installation
Verify that all the database services for ASM are up and running.
To verify ASM is operational following the installation:
1. Change directories to the bin directory in the CRS home directory:
cd /u01/app/crs/bin
2. Run the following command as the oracle user, where docrac1 is the name of
the node you want to check:
./srvctl status asm -n docrac1
ASM instance +ASM1 is running on node docrac1.
The example output shows that there is one ASM instance running on the local
node.
3. Repeat the command shown in Step 2, substituting docrac2 for docrac1 to
verify the successful installation on the other node in your cluster.


3.1.4) Installing the Oracle Database Software and Creating a Cluster Database

The next step is to install the Oracle Database 11g Release 1 software on the docrac1
Node. Before you start OUI you must configure the environment of the oracle user. You
must set the ORACLE_SID, ORACLE_BASE, and ORACLE_HOME environment variables
to the desired values for your environment.

3.1.4.1) To install Oracle Database on your cluster:

1. As the oracle user, use the following commands to start OUI, where
staging_area is the location of the staging area on disk, or the location of the
mounted installation disk:
cd /staging_area/database
./runInstaller
When you start Oracle Universal Installer, the Select a Product to Install window
appears.
2. Select Oracle Database 11g from the list, then click Next.
The Select Installation Type window appears.
3. Select either Enterprise Edition or Standard Edition. The Enterprise Edition option
is selected by default. When finished, click Next.
The Install Location window appears.
4. Specify a name for the Oracle home, for example, OraDb11g_home.
5. Select an Oracle home directory that is a subdirectory of your Oracle base
directory, for example, /opt/oracle/11gR1/db_1.
You can click Browse to change the directory in which the Oracle Database
software will be installed. After you have selected the directory, click Choose
Directory to close the Choose Directory window.
If the directory does not exist, you can type in the directory path in the File Name
field, and then click Choose Directory. If a window appears asking if you want to
create the directory, click Yes.


After you have verified the information on the Install Location window, click
Next.
The Specify Hardware Cluster Installation Mode window appears.
6. Select the nodes on which the Oracle Database software will be installed. You can
also click Select All to select all available nodes. After you have selected the nodes
on which to install the Oracle Database software, click Next.
The Product-Specific Prerequisite Checks window appears.
7. When you see the confirmation message that your system has passed the
prerequisite checks, click Next.
The Select Configuration Option window appears.
8. In the Select Configuration Option window, accept the default option of Create a
Database and click Next.
The Select Database Configuration window appears.
9. Select one of the following different types of databases to be created:
■ General Purpose
■ Transaction Processing
■ Data Warehouse
■ Advanced (for customized database creation)
The General Purpose database type is selected by default. Select the type of
database that best suits your business needs. For the example used by this guide,
the default value is sufficient. After you have selected the database type, click
Next.
The Specify Database Configuration Options window appears.
10. In the Global Database Name field, enter a fully qualified name for your database,
such as sales.mycompany.com. Ensure that the SID field contains the first part
of the database name, for example, sales.


11. Check the settings on each of the tabs. If you are not sure what values to use, then
accept the default values. On the Sample Schemas tab, if you want sample data
and schemas to be created in your database, then select the Create database with
sample schemas option. When finished, click Next to continue.
The Select Database Management Option window appears.
12. By default, the Use Database Control for Database Management option is
selected instead of the Use Grid Control for Database Management option. The
examples in this guide use Database Control, which is the default value.
Do not select the option Enable Email Notifications if your cluster is not connected
to a mail server.


After you have made your selections, click Next.
The Specify Database Storage Option window appears.
13. If you configured ASM on the cluster, select the option Automatic Storage
Management (ASM) for the database storage. Otherwise, select File System and
enter the location of your shared storage, then click Next.
The Specify Backup and Recovery Options window appears.
14. Select the default option Do not enable Automated backup, and then click Next.
You can modify the backup settings at a later time.
If you selected ASM as your storage solution, the Select ASM Disk Group window
appears.
15. The Select ASM Disk Group window shows you where the database files will be
created. Select the disk group that was created during the ASM installation, and
then click Next.


The Specify Database Schema Passwords window appears.
16. Assign and confirm a password for each of the Oracle database schemas.
Unless you are performing a database installation for testing purposes only, do not
select the Use the same password for all the accounts option, as this can
compromise the security of your data. Each password should be at least 8
characters in length and include at least one alphabetic, one numeric, and one
punctuation mark character.
When finished entering passwords, click Next. OUI displays the Privileged
Operating System Groups window.
17. Select the name of the operating system group you created in the previous chapter
for the OSDBA group, the OSASM group, and the database operator group. If you
choose to create only the dba group, then you can use that group for all three
privileged groups. If you created a separate asm group, then use that value for the
OSASM group.


After you have supplied values for the privileged groups, click Next. The Oracle
Configuration Manager Registration window appears.
18. The Oracle Configuration Manager Registration window enables you to configure
the credentials used for connecting to OracleMetaLink. You can provide this
information now, or configure it after the database has been installed. Click Next
to continue.
OUI displays the Summary window.
19. Review the information displayed in the Summary window. If any of the
information is incorrect, click Back to return to a previous window and correct it.
When you are ready to proceed, click Install.
OUI displays a progress indicator to show that the installation has begun. This
step takes several minutes to complete.
20. As part of the software installation process, the sales database is created. At the
end of the database creation, you will see the Oracle Database Configuration
Assistant (DBCA) window with the URL for the Database Control console
displayed.


Make note of the URL, and then click OK. Wait for DBCA to start the cluster
database and its instances.
21. After the installation, you are prompted to perform the postinstallation task of
running the root.sh script on both nodes.


On each node, run the scripts listed in the Execute Configuration scripts window
before you click OK. Perform the following steps to run the root.sh script:
a. Open a terminal window. As the oracle user on docrac1, change directories
to your Oracle home directory, and then switch to the root user by entering
the following commands:
[oracle@docrac1 oracle]$ cd /opt/oracle/11gR1/db_1
[oracle@docrac1 db_1]$ su
b. Enter the password for the root user, and then run the script specified in the
Execute Configuration scripts window:
[root@docrac1 db_1]# ./root.sh
c. As the root.sh script runs, it prompts you for the path to the local bin
directory. The information displayed in the brackets is the information it has
obtained from your system configuration. Press the Enter key each time you
are prompted for input to accept the default choices.
d. After the script has completed, the prompt appears. Enter the following
commands:
[oracle@docrac1 oracle]$ ssh docrac2
[oracle@docrac2 oracle]$ cd /opt/oracle/11gR1/db_1
[oracle@docrac2 db_1]$ su
e. Enter the password for the root user, and then run the script specified in the
Execute Configuration scripts window:
[root@docrac2 db_1]# ./root.sh
f. Accept all default choices by pressing the Enter key.
After you finish executing the script on all nodes, return to the Execute
Configuration scripts window and click OK.
OUI displays the End of Installation window
22. Click Exit and then click Yes to verify that you want to exit OUI.

3.1.4.2) Verifying Your Oracle RAC Database Installation

At this point, you should verify that all the database services are up and running.

To verify the Oracle RAC database services are running:

1. Log in as the oracle user and go to the CRS_home/bin directory:
[oracle] $ cd /u01/app/crs/bin
2. Run the following command to view the status of the applications managed by
Oracle Clusterware:
[oracle] $ ./crs_stat –t
The output of the command should show that the database instances are available
(online) for each host.


3.1.4.3)  Configuring the Operating System Environment for Database Management

After you have installed the Oracle RAC software and created a cluster database, there
are two additional tasks to perform to configure your operating system environment
for easier database management:
■ Updating the oratab File
■ Reconfiguring the User Shell Profile

Updating the oratab File

Several of the Oracle Database utilities use the oratab file to determine the available
Oracle homes and instances on each node. The oratab file is created by the root.sh
script and is updated by Oracle Database Configuration Assistant when creating or
deleting a database.
The following is an example of the oratab file:
# This file is used by ORACLE utilities. It is created by root.sh
# and updated by the Database Configuration Assistant when creating
# a database.
# A colon, ':', is used as the field terminator. A new line terminates
# the entry. Lines beginning with a pound sign, '#', are comments.
#
# Entries are of the form:
# $ORACLE_SID:$ORACLE_HOME:<N|Y>:
#
# The first and second fields are the system identifier and home
# directory of the database respectively. The third field indicates
# to the dbstart utility that the database should, "Y", or should not,
# "N", be brought up at system boot time.
#
# Multiple entries with the same $ORACLE_SID are not allowed.
#
#
+ASM1:/opt/oracle/11gR1/asm:N
sales:/opt/oracle/11gR1/db_1:N
sales1:/opt/oracle/11gR1/db_1:N

To update the oratab file on Red Hat Linux after creating an Oracle RAC
database:

1. Open the /etc/oratab file for editing by using the following command on the
docrac1 node:
vi /etc/oratab
2. Add the Oracle_sid and Oracle_home for the local instance to the end of the
/etc/oratab file, for example:
sales1:/opt/oracle/11gR1/db_1:N
3. Save the file and exit the vi editor.
4. Modify the /etc/oratab file on each node in the cluster, adding in the
appropriate instance information.

Reconfiguring the User Shell Profile

There are several environment variables that can be used with Oracle RAC or Oracle
Database. These variables can be set manually in your current operating system
session, using shell commands such as set and export.
You can also have these variables set automatically when you log in as a specific
operating system user. To do this, modify the Bourne, Bash, or Korn shell
configuration file (for example .profile or .login) for that operating system user.

To modify the oracle user’s profile for the bash shell on Red Hat Linux:

1. As the oracle user, open the user profile in the /home/oracle directory for
editing using the following commands:
[oracle] $ cd $HOME
[oracle] $ vi .bash_profile
2. Modify the following lines in the file so they point to the location of the newly
created Oracle RAC database:
export ORACLE_BASE=/opt/oracle/11gR1
export ORACLE_HOME=/opt/oracle/11gR1/db_1
export PATH=$ORACLE_HOME/bin:$PATH
3. On each node, modify the .bash_profile file to set the ORACLE_SID
environment variable to the name of the local instance. For example, on the host
docrac1 you would add the following line to the .bash_profile file:
export ORACLE_SID=sales1
On the host docrac2 you would set ORACLE_SID to the value sales2.
4. Read and implement the changes made to the .bash_profile file on each
instance:
source .bash_profile
5. On each client computer, configure user access to use a service name, such as
sales, for connecting to the database.

3.1.5)  Performing Postinstallation Tasks

After you have installed the Oracle RAC software, there are additional tasks that you
can perform before your cluster database is ready for use. These steps are
recommended, but are not required.
This section contains the following topics:
■ About Verifying the Oracle Clusterware Installation
■ About Backing Up the Voting Disk
■ About Downloading and Installing RDBMS Patches
■ Verifying Oracle Enterprise Manager Operations
■ Recommended Postinstallation Tasks

3.1.5.1)  About Verifying the Oracle Clusterware Installation
After the Oracle Clusterware installation is complete, OUI automatically runs the
cluvfy utility as a Configuration Assistant to verify that the Clusterware installation
has been completed successfully.
If the CVU reports problems with your configuration, correct these errors before
proceeding.

3.1.5.2)  About Backing Up the Voting Disk
After your Oracle Database 11g with Oracle RAC installation is complete, and after
you are sure that your system is functioning properly, make a backup of the contents
of the voting disk. Use the dd utility, as described in the section "About Backing Up
and Recovering Voting Disks".
Also, make a backup copy of the voting disk contents after you complete any node
additions or deletions, and after running any deinstallation procedures.

3.1.5.3)  About Downloading and Installing RDBMS Patches
Periodically, Oracle issues bug fixes for its software called patches. Patch sets are a
collection of bug fixes that were produced up to the time of the patch set release. Patch
sets are fully tested product fixes. Application of a patch set affects the software
residing in your Oracle home.
Ensure that you are running the latest patch set of the installed software. You might
also need to apply patches that are not included in a patch set. Information about
downloading and installing patches and patch sets is covered in Chapter 10,
"Managing Oracle Software and Applying Patches".

3.1.5.4)  Verifying Oracle Enterprise Manager Operations
When you create an Oracle RAC database and choose Database Control for your
database management, the Enterprise Manager Database Control utility is installed
and configured automatically.

To verify Oracle Enterprise Manager Database Control has been started in your
new Oracle RAC environment:

1. Make sure the ORACLE_SID environment variable is set to the name of the
instance to which you want to connect, for example sales1. Also make sure the
ORACLE_HOME environment variable is set to the location of the installed Oracle
Database software.
$ echo $ORACLE_SID
sales
$ export ORACLE_SID=sales1
$ echo $ORACLE_HOME
/opt/oracle/11gR1/db_1
2. Go to the Oracle_home/bin directory.
3. Run the following command as the oracle user:
./emctl status dbconsole
The Enterprise Manager Control (EMCTL) utility displays the current status of the
Database Control console on the current node.
4. If the EMCTL utility reports that Database Control is not started, use the following
command to start it:
./emctl start dbconsole
5. Repeat Step 1 through Step 3 for each node in the cluster.

3.1.5.5)  Recommended Postinstallation Tasks

Oracle recommends that you complete the following tasks after installing Oracle RAC:
■ About Backing Up the root.sh Script
■ About Configuring User Accounts

About Backing 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, OUI
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 backup copy.

About Configuring User Accounts

The oracle user operating system account is the account that you used to install the
Oracle software. You can use different operating system accounts for accessing and
managing your Oracle RAC database.




KEY TERMS
SWAP SPACE- Swap space is an area on disk that temporarily holds a process memory image. When physical memory demand is sufficiently low, process memory images are brought back into physical memory from the swap area on disk. Having sufficient swap space enables the system to keep some physical memory free at all times.
This type of memory management is often referred to as virtual memory and allows the total number of processes to exceed physical memory. Virtual memory enables the execution of a process within physical memory only as needed.
VIRTUAL IP-A virtual IP address (VIP or VIPA) is an IP address that is not connected to a specific computer or network interface card (NIC) on a computer. Incoming packets are sent to the VIP address, but they are redirected to physical network interfaces.VIPs are mostly used for connection redundancy; a VIP address may still be available if a computer or NIC fails because an alternative computer or NIC replies to connections
CACHE FUSION- Prior to Oracle 9, network-clustered Oracle databases used a storage device as the data-transfer medium (meaning that one node would write a data block to disk and another node would read that data from the same disk), which had the inherent disadvantage of lacklustre performance. Oracle 9i addressed this issue: RAC uses a dedicated network-connection for communications internal to the cluster.
Since all computers/instances in an RAC access the same database, the overall system must guarantee the coordination of data changes on different computers such that whenever a computer queries data it receives the current version — even if another computer recently modified that data. Oracle RAC refers to this functionality as Cache Fusion. Cache Fusion involves the ability of Oracle RAC to "fuse" the in-memory data cached physically separately on each computer into a single, global cache.
NTP(Network Time Protocol)- NTP is a protocol designed to synchronize the clocks of servers connected by a network.

RAW devices- a raw device is a special kind of block device file that allows accessing a storage device such as a hard drive directly, bypassing the operating system's caches and buffers (although the hardware caches might still be used). Applications like a Database management system can use raw devices

 




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