Oracle® Real Application Clusters Installation and Configuration Guide
10g Release 1 (10.1.0.3) for Linux x86-64
Part No. B14406-01
This chapter provides an overview of the Real Application Clusters (RAC) installation and configuration procedures and includes the following topics:
This section describes the RAC documentation set. The Oracle Database 10g CD contains a copy of this book, the Oracle Real Application Clusters Installation and Configuration Guide in both HTML and PDF formats. This book contains the pre-installation, installation, and post-installation information for platform.
The Server Documentation CD contains the following additional documentation about RAC administration and deployment: the Oracle Real Application Clusters Administrator's Guide and the Oracle Real Application Clusters Deployment and Performance Guide as described under the following headings:
The Oracle Real Application Clusters Administrator's Guide provides RAC-specific administration information. Some of the topics described in this book include the use of Oracle Enterprise Manager in RAC environments. The book also describes how to administer services and storage and how to use RAC scalability features to add and delete instances and nodes in RAC environments. The book also discusses how to use Recovery Manager (RMAN) and how to perform backup and recovery in RAC.
The Oracle Real Application Clusters Administrator's Guide also describes how to use the Server Control (SRVCTL) utility to start and stop the database and instances, manage configuration information, and to delete or move instances and services. You can also use the appendix to resolve various RAC tools messages. A troubleshooting section describes how to interpret the content of RAC-specific log files.
The Oracle Real Application Clusters Deployment and Performance Guide highlights the main deployment topics for RAC by briefly describing Cluster Ready Services (CRS), storage, database creation, and services deployment in RAC. Design and deployment topics in this book describe service topologies and workload management in RAC. Specifically, the book describes how the Automatic Workload Repository tracks and reports service levels and how you can use service level thresholds and alerts to improve high availability in your RAC environment. There is also a services deployment example in the appendix of this book that you can use to learn more about how to deploy and manage services in RAC environments.
The Oracle Real Application Clusters Deployment and Performance Guide provides a high-level description of interconnect protocols, as well as information about how to monitor and tune performance in RAC environments using both Oracle Enterprise Manager and using information in the Automated Workload Repository and Oracle performance views. The book also highlights some application-specific deployment techniques for online transaction processing and data warehousing environments.
Each node that is going to be part of your RAC installation must meet the following hardware and software requirements. You will also perform step-by-step tasks for hardware and software verification for Linux x86-64 specific pre-installation procedures in Part II of this book.
Before using this manual, however, you should read the Oracle Real Application Clusters Deployment and Performance Guide and the Oracle Real Application Clusters Administrator's Guide.
Each node in a cluster requires a supported interconnect software protocol to support Cache Fusion, and Cluster Ready Services (CRS) polling. Your interconnect must be certified by Oracle for your platform. You should also have a Web browser to enable Oracle Enterprise Manager and to view online documentation.
Before installing RAC, perform the following procedures:
Ensure that you have a certified combination of operating system and Oracle software version by referring to the OracleMetaLink certification information under "Availability & Certification" > "1.View Certifications by Product" at the following site:
Note:The layout of the MetaLink site and the site's certification policies are subject to change.
Configure a high-speed interconnect that uses a private network. Configure a second interconnect for redundancy, if the interconnect redundancy is supported by the platform, to avoid making the interconnect a single point of failure. Some platforms support automatic failover to the alternate interconnect. To enable this, you must configure the operating system-provided failover mechanism.
Determine the storage option for your system and configure the shared disk. Oracle recommends that you use Automatic Storage Management (ASM) and Oracle Managed Files (OMF), or a cluster file system. If you use ASM or a cluster file system, then you can also take advantage of OMF and other Oracle Database 10g storage features. If you use RAC on the Oracle Database 10g Standard Edition, then you must use ASM.
Note:If you use ASM, Oracle recommends that you install ASM in a separate home from the CRS home and the Oracle home, particularly if the ASM instance is to manage storage for more than one RAC database. This reduces downtime when upgrading or de-installing different versions of the software. However, you must create the ASM instance manually because the OUI and DBCA do not support a separate install of ASM.
Install the operating system patches that are listed in the pre-installation chapters in this book in Part II.
The pre-installation procedures in Part II explain how to verify user equivalence, perform network connectivity tests, as well as how to set directory and file permissions. Complete all of the pre-installation procedures and verify that your system meets all of the pre-installation requirements before proceeding to the install phase.
The Oracle Database 10g Real Application Clusters installation is a two-phase installation. In phase one, use the Oracle Universal Installer (OUI) to install CRS as described in Chapter 3, "Installing Cluster Ready Services on Linux Systems". Note that the Oracle home that you use in phase one is a home for the CRS software which must be different from the Oracle home that you use in phase two for the installation of the Oracle database software with RAC components. The CRS pre-installation starts the CRS processes in preparation for installing Oracle Database 10g with RAC as described in Chapter 4, "Installing Oracle Database 10g with Real Application Clusters". You use the OUI in this phase to install the RAC software.
If the OUI detects Oracle cluster software from a previous release, then the OUI starts the Database Upgrade Assistant (DBUA) to upgrade your database to Oracle Database 10g release 1 (10.1.0.3). In addition, the DBUA displays a Service Configuration page for configuring services in your RAC database.
After the installation completes, the OUI starts the Oracle assistants, such as the DBCA, to configure your environment and create your RAC database. You can later use the DBCA Instance Management feature to add or modify services and instances as described in Chapter 5, "Creating RAC Databases with the Database Configuration Assistant".
After you create your database, download and install the most recent patch sets for your Oracle Database 10g version as described in Chapter 6, "Real Application Clusters Post-Installation Procedures". If you are using other Oracle products with your RAC database, then you must also configure them.
You must also perform several post-installation configuration tasks to use certain Oracle Database 10g products such as the Sample Schema, Oracle Net Services, or Oracle Messaging Gateway. You must also configure Oracle pre-compilers for your operating system and if desired, configure Oracle Advanced Security.
Use the Companion CD to install additional Oracle Database 10g software that may improve performance or extend database capabilities, for example, Oracle JVM, Oracle interMedia or Oracle Text.
See Also:Oracle Real Application Clusters Administrator's Guide for more information about using RAC scalability features of adding and deleting nodes and instances from RAC databases
The Oracle Universal Installer (OUI) facilitates the installation of Cluster Ready Services (CRS) and Oracle Database 10g software. In most cases, you use the graphical user interface (GUI) provided by the OUI to install the software. However, you can also use the OUI to complete non-interactive installations, without using the GUI. See Appendix B for information about non-interactive installations.
When the OUI installs the Oracle software, Oracle recommends that you select a preconfigured database or use the Database Configuration Assistant (DBCA) interactively to create your cluster database. You can also manually create your database as described in procedures posted at
http://www.oracle.com/technology/. Oracle recommends that you use Automatic Storage Management (ASM). If you are not using ASM or if you are not using a cluster file system, then configure shared raw devices before you create your database.
When you install CRS or RAC, the OUI copies the Oracle software onto the node from which you are running it. If your Oracle home is not on a cluster file system, then the OUI propagates the software onto the other nodes that you have selected to be part of your OUI installation session.
When you create your RAC database using the OUI, or if you do it later using the DBCA, or if you use the Enterprise Manager Configuration Assistant to configure Enterprise Manager, Enterprise Manager is configured for your cluster database. Database control can manage your RAC database, all of its instances, and the hosts where instances are configured.
You can also configure Enterprise Manager Grid Control to manage multiple databases and application servers from a single console. To manage RAC databases in Grid Control, you must install a Grid Control agent on each of the nodes of your cluster. The Agent installation is clusterized, which means you need to perform the install on only one of the cluster nodes.
Oracle recommends using Automatic Storage Management (ASM) or a cluster file system with Oracle Managed Files (OMF) for database storage. This section provides an overview of ASM.
Note that RAC installations using the Oracle Database Standard Edition must use ASM for database file storage.
You can use ASM to simplify the administration of Oracle database files. Instead of having to manage potentially thousands of database files, using ASM, you need to manage only a small number of disk groups. A disk group is a set of disk devices that ASM manages as a single logical unit. You can define a particular disk group as the default disk group for a database, and Oracle will automatically allocate storage for, create, or delete, the files associated with the appropriate database object. When administering the database, you need only refer to database objects by name, rather than by file name.
When using ASM with a single Oracle home for database instances on a node, the ASM instance can run from that same home. If you are using ASM with Oracle database instances from multiple database homes on the same node, then Oracle recommends that you run the ASM instance from an Oracle home that is distinct from the database homes. In addition, the ASM home should be installed on every cluster node. This prevents the accidental removal of ASM instances that are in use by databases from other homes during the de-installation of a database Oracle home.
Benefits of Automatic Storage Management
ASM provides many of the same benefits as storage technologies such as RAID or logical volume managers (LVMs). Like these technologies, ASM enables you to create a single disk group from a collection of individual disk devices. It balances I/O to the disk group across all of the devices in the disk group. It also implements striping and mirroring to improve I/O performance and data reliability.
However, unlike RAID or LVMs, ASM implements striping and mirroring at the file level. This implementation enables you to specify different storage attributes for individual files in the same disk group.
Disk Groups and Failure Groups
A disk group can include any number of disk devices. Each disk device can be an individual physical disk, a multiple disk device such as a RAID storage array or logical volume, or even a partition on a physical disk. However, in most cases, disk groups consist of one or more individual physical disks. To enable ASM to balance I/O and storage appropriately within the disk group, all devices in the disk group should have similar, if not identical, storage capacity and performance.
Note:Do not specify more than one partition on a single physical disk as a disk group device. ASM expects each disk group device to be on a separate physical disk.
Although you can specify a logical volume as a device in an ASM disk group, Oracle does not recommend their use. Because logical volume managers can hide the physical disk architecture, ASM may not operate effectively when logical volumes are specified as disk group devices.
When you add a device to a disk group, you can specify a failure group for that device. Failure groups identify disk devices that have common failure characteristics, for example, devices that are attached to the same controller. If the controller fails, then all devices attached to it become unavailable. By default, each device also belongs to its own failure group. By using the failure groups you specify, ASM can distribute data among the devices in the disk group to help minimize the risk of data loss caused by component failures.
The disk group contains devices, such as RAID devices, that provide their own data protection
Your use of the database does not require uninterrupted access to data, for example, in a development environment where you have a suitable back-up strategy
In disk groups created with normal redundancy, the contents of the disk group are two-way mirrored by default. However, you can choose to create certain files that are not mirrored. To create a disk group with normal redundancy, you must specify at least two failure groups (a minimum of two devices).
The effective disk space of a disk group that uses normal redundancy is half the total disk space of all of its devices.
In disk groups created with high redundancy, the contents of the disk group are three-way mirrored by default. However, you can choose to create certain files that are only two-way mirrored, or that are not mirrored. To create a disk group with high redundancy, you must specify at least three failure groups (a minimum of three devices).
The effective disk space of a disk group that uses high redundancy is one-third of the total disk space of all of its devices.
ASM and Installation Types
The type and number of disk groups that you can create when installing Oracle software depends on the type of database you choose to create during the installation, as follows:
If you choose to create the default preconfigured database that uses ASM, the OUI prompts you to specify two disk device names, which it uses to create a disk group named DATA, with normal redundancy.
If you choose to create an advanced database that uses ASM, you can create one or more disk groups. These disk groups can use one or more devices. For each disk group, you can specify the redundancy level that suits your requirements.
|Redundancy Level||Total DIsk Space Required|
|Normal||2 GB (on a minimum of two devices)|
|High||3 GB (on a minimum of three devices)|
Oracle recommends using the following Oracle Database 10g features to simplify RAC database management:
Enterprise Manager: Use Enterprise Manager to administer your entire processing environment, not just the RAC database. Enterprise Manager enables you to manage a RAC database with its instance targets, listener targets, host targets, and a cluster target, as well as ASM targets if you are using ASM storage for your database.
Automatic undo management: Automatically manages undo processing.
Automatic segment-space management: Automatically manages segment freelists and freelist groups.
Locally managed tablespaces: Enhances space management performance.
See Also:The Oracle Real Application Clusters Administrator's Guide for more information about these features in RAC environments
Oracle Database 10g provides single-instance database software and the additional components to operate RAC databases. Some of the RAC-specific components include:
Cluster Ready Services (CRS)
A RAC-enabled Oracle home
The OUI installs CRS on each node on which the OUI detects that Oracle9
i cluster manager is present. If vendor clusterware is not present, then you must use the OUI to enter the nodes on which to install CRS. The CRS home can be either shared by all nodes or private to each node depending on your responses when you run the OUI. The home that you select for CRS must be different from the RAC-enabled Oracle home.
When vendor clusterware is present, CRS interacts with the vendor clusterware to coordinate cluster membership information. For Oracle Database 10g on Linux, CRS coexists with but does not interact with previous Oracle clusterware versions.
Note:On Linux, pre-Oracle Database 10g cluster manager implementations were referred to as "Cluster Manager". In Oracle Database 10g, the cluster manager role is performed by Cluster Synchronization Services (CSS), a component of CRS. The OCSSD performs this function.
All instances in RAC environments share the control file, server parameter file, redo log files, and all datafiles. These files reside on a shared cluster file system or on shared disks. Either of these types of file configurations are accessed by all the cluster database instances. Each instance also has its own set of redo log files. During failures, shared access to redo log files enables surviving instances to perform recovery.
You can install and operate different versions of Oracle cluster database software on the same computer as described in the following points:
If you run the OUI to install RAC on a system that already has an Oracle Database 10g RAC installation, then the OUI prompts you to install additional Oracle Database 10g products if you have not already installed all of them.
You can also install multiple Oracle Database 10g RAC homes on the same node. The multiple homes feature enables you to install one or more releases on the same machine in multiple Oracle home directories. However, each node can have only one CRS home.
The OUI also enables you to de-install and re-install Oracle Database 10g Real Application Clusters if needed.
In addition, you cannot install Oracle Database 10g RAC into an existing Oracle home. If you have an Oracle home for Oracle Database 10g, then use a different Oracle home, and one that is available across the entire cluster for your new installation. Similarly, if you have an Oracle home for an earlier Oracle cluster database software release, then you must also use a different home for the new installation.
If the OUI detects an earlier version of a database, then the OUI asks you about your upgrade preferences. You have the option to upgrade one of the previous-version databases with DBUA or to create a new database using DBCA. The information collected during this dialog is passed to DBUA or DBCA after the software is installed.
Note:Do not move Oracle binaries from one Oracle home to another because this causes dynamic link failures.
This section describes information specific to RAC on UNIX-based platforms. Depending on whether this is the first time you are installing the Oracle server software on your Linux system, you may need to create several UNIX groups and a UNIX user as described later in the pre-installation procedures. The required UNIX groups and user are:
The Oracle Inventory group (
You must create this group the first time you install Oracle software on the system. The usual name for this group is
oinstall. This group owns the Oracle inventory which is a catalog of all of the Oracle software installed on the system.
The OSDBA group (
You must create this group the first time you install Oracle software on the system. It identifies users that have database administrative privileges (the
SYSOPER privileges). The default name for this group is
dba. To specify a group name other than the default, choose the Custom installation type to install the software. You must also create an OSDBA group if an OSBDA group exists but you want to give a different group of users database administrative privileges in a new Oracle server installation.
The OSOPER group (
This is an optional group. Create this group if you want a separate group of users to have a limited set of database administrative privileges (the
SYSDBA privilege). The default name for this group is
oper. To use this group, choose the Custom installation type to install the software. To use an OSOPER group, you must create it in the following circumstances:
If an OSOPER group does not exist, for example, if this is the first installation of Oracle server software on the system
If an OSOPER group exists but you want to give a different group of users database operator privileges in a new Oracle server installation
The Oracle Software Owner user (
You must create this user the first time you install Oracle software on the system. This user owns all of the software installed during the installation. The usual name for this user is
oracle. This user must have the Oracle Inventory group as its primary group and the OSDBA group as its secondary group. It must also have the OSOPER group as a secondary group if you choose to create that group. If an Oracle software owner user exists, but you want to use a different user, with different group membership, in a new Oracle server installation, you must give database administrative privileges to those groups.
A single Oracle Inventory group is required for all installations of Oracle software on the system. However, you can create different Oracle software owner users, OSDBA groups, and OSOPER groups (other than
oper) for separate installations. Using different groups enables you to grant
DBA privileges to a particular operating system user on one database, which they would not have on another database on the same system.
See Also:The Oracle Database Administrator's Reference, 10g Release 1 (10.1) for UNIX Systems and the Oracle Database 10g Administrator's Guide contain more information about the OSDBA and OSOPER groups and the