3 Configuring Oracle Clusterware and Oracle Database Storage

3.1.1 Overview of Storage Options

Use the following overview to help you select your storage option:

http://metalink.oracle.com

3.1.2 Checking for Available Shared Storage with CVU

To check for all shared file systems available across all nodes on the cluster with an NFS file system, use the following command:

/mountpoint/clusterware/cluvfy/runcluvfy.sh comp ssa -n node_list

If you want to check the shared accessibility of a specific shared storage type to specific nodes in your cluster, then use the following command syntax:

/mountpoint/clusterware/cluvfy/runcluvfy.sh comp ssa -n node_list -s storageID_list

In the preceding syntax examples, the variable mountpoint is the mountpoint path of the installation media, the variable node_list is the list of nodes you want to check, separated by commas, and the variable storageID_list is the list of storage device IDs for the storage devices managed by the file system type that you want to check.

For example, if you want to check the shared accessibility from node1 and node2 of storage devices /dev/c0t0d0s2 and /dev/c0t0d0s3, and your mountpoint is /dev/dvdrom/, then enter the following command:

/dev/dvdrom/clusterware/cluvfy/runcluvfy.sh comp ssa -n node1,node2 -s\ /dev/c0t0d0s2,/dev/c0t0d0s3

If you do not specify specific storage device IDs in the command, then the command searches for all available storage devices connected to the nodes on the list

3.2.1 Requirements for Using a file system for Oracle Clusterware Files

To use a file system for Oracle Clusterware files, the file system must comply with the following requirements

• To use an NFS file system, it must be on a certified NAS device

  
  

  Note: If you are using a shared file system on a NAS device to store a shared Oracle home directory for Oracle Clusterware or RAC, then you must use the same NAS device for Oracle Clusterware file storage.

  
  

• If you choose to place your Oracle Cluster Registry (OCR) files on a shared file system, then you should ensure one of the following is true:

  • Either ensure that the disks used for the file system are on a highly available storage device, (for example, a RAID device that implements file redundancy), or mount at least two file systems, and use the features of Oracle Database 10g Release 2 (10.2) to provide redundancy for the OCR.

• If you intend to use a shared file system to store database files, then you should ensure that you use at least two independent file systems, with the database files on one file system, and the recovery files on a different file system.

• The oracle user must have write permissions to create the files in the path that you specify.

Use Table 3-1 to determine the partition size for shared file systems:

In Table 3-1, the total required volume size is cumulative. For example, to store all files on the shared file system, you should have at least 3.4 GB of storage available over a minimum of two volumes.

3.2.2 Checking NFS Buffer Size Parameters

If you are using NFS, then you must set the values for the NFS buffer size parameters rsize and wsize to at least 16384. Oracle recommends that you use the value 32768.

For example, if you decide to use rsize and wsize buffer settings with the value 32768, then update the /etc/vfstab file on each node with an entry similar to the following:

nfs_server:/vol/DATA/oradata  /home/oracle/netapp nfs -yes     rw,hard,nointr,rsize=32768,wsize=32768,tcp,noac,vers=3

If you use NFS mounts, then Oracle recommends that you use the option forcedirectio to force direct I/O for better performance. However, if you add forcedirectio to the mount option, then the same mount point cannot be used for Oracle software binaries, executables, shared libraries, and objects. You can only use the forcedirectio option for Oracle data files, the OCR, and voting disks. For these mount points, enter the following line:

nfs_server:/vol/DATA/oradata  /home/oracle/netapp nfs -yes     rw,hard,nointr,rsize=32768,wsize=32768,tcp,noac,forcedirectio,vers=3

3.2.3 Creating Required Directories for Oracle Clusterware Files on Shared File Systems

Use the following instructions to create directories for Oracle Clusterware files. If you intend to use a file system to store Oracle Clusterware files, then you can also configure file systems for the Oracle Database and recovery files.

To create directories for the Oracle Clusterware files on separate file systems to the Oracle base directory, follow these steps:

1. If necessary, configure the shared file systems that you want to use and mount them on each node.

   
   

   Note: The mount point that you use for the file system must be identical on each node. Make sure that the file systems are configured to mount automatically when a node restarts.

   
   

2. Use the df -k command to determine the free disk space on each mounted file system.

3. From the display, identify the file systems that you want to use:

   File Type	File System Requirements
   Oracle Clusterware files	Choose a file system with at least 120 MB of free disk space
   Database files	Choose either: A single file system with at least 1.2 GB of free disk space Two or more file systems with at least 1.2 GB of free disk space in total
   Recovery files	Choose a file system with at least 2 GB of free disk space.

   
   

   If you are using the same file system for more than one type of file, then add the disk space requirements for each type to determine the total disk space requirement.

4. Note the names of the mount point directories for the file systems that you identified.

5. If the user performing installation (typically, oracle) has permissions to create directories on the disks where you plan to install Oracle Clusterware and Oracle Database, then OUI creates the Oracle Clusterware file directory, and DBCA creates the Oracle Database file directory, and the Recovery file directory.

   If the user performing the installation does not have write access, then you must create these directories manually using commands similar to the following to create the recommended subdirectories in each of the mount point directories and set the appropriate owner, group, and permissions on them:

   • Oracle Clusterware file directory:

     # mkdir /mount_point/oracrs
     # chown oracle:oinstall /mount_point/oracrs
     # chmod 775 /mount_point/oracrs
     
     

   • Database file directory:

     # mkdir /mount_point/oradata
     # chown oracle:oinstall /mount_point/oradata
     # chmod 775 /mount_point/oradata
     
     

   • Recovery file directory (flash recovery area):

     # mkdir /mount_point/flash_recovery_area
     # chown oracle:oinstall /mount_point/flash_recovery_area
     # chmod 775 /mount_point/flash_recovery_area
     
     

By making the Oracle user the owner of these directories, this permits them to be read by multiple Oracle homes, including those with different OSDBA groups.

When you have completed creating subdirectories in each of the mount point directories, and set the appropriate owner, group, and permissions, you have completed CFS or NFS configuration.

3.3.1 Identifying Required Raw Partitions for Clusterware Files

Table 3-2 lists the number and size of the raw partitions that you must configure for Oracle Clusterware files.

3.5.1 Identifying Storage Requirements for Automatic Storage Management

To identify the storage requirements for using Automatic Storage Management, you must determine how many devices and the amount of free disk space that you require. To complete this task, follow these steps:

1. Determine whether you want to use Automatic Storage Management for Oracle Database files, recovery files, or both.

   
   

   Note: You do not have to use the same storage mechanism for database files and recovery files. You can use the file system for one file type and Automatic Storage Management for the other. If you choose to enable automated backups and you do not have a shared file system available, then you must choose Automatic Storage Management for recovery file storage.

   
   

   If you enable automated backups during the installation, you can choose Automatic Storage Management as the storage mechanism for recovery files by specifying an Automatic Storage Management disk group for the flash recovery area. Depending on how you choose to create a database during the installation, you have the following options:

   • If you select an installation method that runs Database Configuration Assistant in interactive mode (for example, by choosing the Advanced database configuration option) then you can decide whether you want to use the same Automatic Storage Management disk group for database files and recovery files, or you can choose to use different disk groups for each file type.

     The same choice is available to you if you use Database Configuration Assistant after the installation to create a database.

   • If you select an installation method that runs Database Configuration Assistant in noninteractive mode, then you must use the same Automatic Storage Management disk group for database files and recovery files.

2. Choose the Automatic Storage Management redundancy level that you want to use for the Automatic Storage Management disk group.

   The redundancy level that you choose for the Automatic Storage Management disk group determines how Automatic Storage Management mirrors files in the disk group and determines the number of disks and amount of disk space that you require, as follows:

   • External redundancy

     An external redundancy disk group requires a minimum of one disk device. The effective disk space in an external redundancy disk group is the sum of the disk space in all of its devices.

     Because Automatic Storage Management does not mirror data in an external redundancy disk group, Oracle recommends that you use only RAID or similar devices that provide their own data protection mechanisms as disk devices in this type of disk group.

   • Normal redundancy

     In a normal redundancy disk group, Automatic Storage Management uses two-way mirroring by default, to increase performance and reliability. A normal redundancy disk group requires a minimum of two disk devices (or two failure groups). The effective disk space in a normal redundancy disk group is half the sum of the disk space in all of its devices.

     For most installations, Oracle recommends that you select normal redundancy disk groups.

   • High redundancy

     In a high redundancy disk group, Automatic Storage Management uses three-way mirroring to increase performance and provide the highest level of reliability. A high redundancy disk group requires a minimum of three disk devices (or three failure groups). The effective disk space in a high redundancy disk group is one-third the sum of the disk space in all of its devices.

     While high redundancy disk groups do provide a high level of data protection, you must consider the greater cost of additional storage devices before deciding to select high redundancy disk groups.

3. Determine the total amount of disk space that you require for the database files and recovery files.

   Use the following table to determine the minimum number of disks and the minimum disk space requirements for the installation:

   Redundancy Level	Minimum Number of Disks	Database Files	Recovery Files	Both File Types
   External	1	1.15 GB	2.3 GB	3.45 GB
   Normal	2	2.3 GB	4.6 GB	6.9 GB
   High	3	3.45 GB	6.9 GB	10.35 GB

   
   

   For RAC installations, you must also add additional disk space for the Automatic Storage Management metadata. You can use the following formula to calculate the additional disk space requirements (in MB):

   15 + (2 * number_of_disks) + (126 * number_of_Automatic_Storage_Management_instances)

   For example, for a four-node RAC installation, using three disks in a high redundancy disk group, you require an additional 525 MB of disk space:

   15 + (2 * 3) + (126 * 4) = 525

   If an Automatic Storage Management instance is already running on the system, then you can use an existing disk group to meet these storage requirements. If necessary, you can add disks to an existing disk group during the installation.

   The following section describes how to identify existing disk groups and determine the free disk space that they contain.

4. Optionally, identify failure groups for the Automatic Storage Management disk group devices.

   
   

   Note: You need to complete this step only if you intend to use an installation method that runs Database Configuration Assistant in interactive mode, for example, if you intend to choose the Custom installation type or the Advanced database configuration option. Other installation types do not enable you to specify failure groups.

   
   

   If you intend to use a normal or high redundancy disk group, then you can further protect your database against hardware failure by associating a set of disk devices in a custom failure group. By default, each device comprises its own failure group. However, if two disk devices in a normal redundancy disk group are attached to the same SCSI controller, then the disk group becomes unavailable if the controller fails. The controller in this example is a single point of failure.

   To protect against failures of this type, you could use two SCSI controllers, each with two disks, and define a failure group for the disks attached to each controller. This configuration would enable the disk group to tolerate the failure of one SCSI controller.

   
   

   Note: If you define custom failure groups, then you must specify a minimum of two failure groups for normal redundancy disk groups and three failure groups for high redundancy disk groups.

   
   

5. If you are sure that a suitable disk group does not exist on the system, then install or identify appropriate disk devices to add to a new disk group. Use the following guidelines when identifying appropriate disk devices:

   • All of the devices in an Automatic Storage Management disk group should be the same size and have the same performance characteristics.

   • Do not specify more than one partition on a single physical disk as a disk group device. Automatic Storage Management expects each disk group device to be on a separate physical disk.

   • Although you can specify a logical volume as a device in an Automatic Storage Management disk group, Oracle does not recommend their use. Logical volume managers can hide the physical disk architecture, preventing Automatic Storage Management from optimizing I/O across the physical devices.

   
   

   See Also: The "Configuring Disks for Automatic Storage Management" section for information about completing this task

   
   

3.5.2 Using an Existing Automatic Storage Management Disk Group

If you want to store either database or recovery files in an existing Automatic Storage Management disk group, then you have the following choices, depending on the installation method that you select:

• If you select an installation method that runs Database Configuration Assistant in interactive mode (for example, by choosing the Advanced database configuration option), then you can decide whether you want to create a disk group, or use an existing one.

  The same choice is available to you if you use Database Configuration Assistant after the installation to create a database.

• If you select an installation method that runs Database Configuration Assistant in noninteractive mode, then you must choose an existing disk group for the new database; you cannot create a disk group. However, you can add disk devices to an existing disk group if it has insufficient free space for your requirements.

To determine whether an existing Automatic Storage Management disk group exists, or to determine whether there is sufficient disk space in a disk group, you can use Oracle Enterprise Manager Grid Control or Database Control. Alternatively, you can use the following procedure:

1. View the contents of the oratab file to determine whether an Automatic Storage Management instance is configured on the system:

   # more /var/opt/oracle/oratab
   
   

   If an Automatic Storage Management instance is configured on the system, then the oratab file should contain a line similar to the following:

   +ASM2:oracle_home_path
   
   

   In this example, +ASM2 is the system identifier (SID) of the Automatic Storage Management instance, with the node number appended, and oracle_home_path is the Oracle home directory where it is installed. By convention, the SID for an Automatic Storage Management instance begins with a plus sign.

2. Set the ORACLE_SID and ORACLE_HOME environment variables to specify the appropriate values for the Automatic Storage Management instance that you want to use.

3. Connect to the Automatic Storage Management instance as the SYS user with SYSDBA privilege and start the instance if necessary:

   # $ORACLE_HOME/bin/sqlplus "SYS/SYS_password as SYSDBA"
   SQL> STARTUP
   
   

4. Enter the following command to view the existing disk groups, their redundancy level, and the amount of free disk space in each one:

   SQL> SELECT NAME,TYPE,TOTAL_MB,FREE_MB FROM V$ASM_DISKGROUP;
   
   

5. From the output, identify a disk group with the appropriate redundancy level and note the free space that it contains.

6. If necessary, install or identify the additional disk devices required to meet the storage requirements listed in the previous section.

   
   

   Note: If you are adding devices to an existing disk group, then Oracle recommends that you use devices that have the same size and performance characteristics as the existing devices in that disk group.

   
   

3.5.3 Configuring Database File Storage on ASM and Raw Devices

To configure disks for Automatic Storage Management (ASM) using raw devices, complete the following tasks:

1. To use ASM with raw partitions, you must create sufficient partitions for your data files, and then bind the partitions to raw devices. To do this, follow the instructions provided for Oracle Clusterware in the section "Configuring Storage for Oracle Clusterware Files on Raw Devices".

2. Make a list of the raw device names you create for the data files, and have it available during database installation.

When you have completed creating and configuring ASM with raw partitions, proceed to Chapter 4, "Installing Oracle Clusterware"

3.6.1 Configuring Raw Logical Volumes for Database File Storage

This section describes how to configure raw logical volumes using VERITAS Cluster Volume Manager (CVxVM) with Sun Cluster 3.1 on SPARC systems.

Creating a Shared Disk Group

To create a shared disk group:

1. If necessary, install the shared disks that you intend to use for the disk group and restart the system.

2. To ensure that the disks are available, enter the following command:

   # /usr/sbin/format
   
   

   The output from this command is similar to the following:

   AVAILABLE DISK SELECTIONS:
          0. c0t0d0 <ST34321A cyl 8892 alt 2 hd 15 sec 63>
             /pci@1f,0/pci@1,1/ide@3/dad@0,0
          1. c1t5d0 <SUN9.0G cyl 4924 alt 2 hd 27 sec 133>
             /pci@1f,0/pci@1/scsi@1/sd@5,0
   
   

   This command displays information about each disk attached to the system, including the device name (cxtydz).

3. From the list, identify the device names for the disk devices that you want to add to a disk group, then use Ctrl+D to exit from the format utility.

4. Enter the following command on every node to verify that the devices you identified are not mounted as file systems:

   # df -k
   
   

   This command displays information about the partitions (slices) on disk devices that are mounted as file systems. The device name for a slice includes the disk device name followed by the slice number, for example cxtydzsn, where sn is the slice number. Slice 2 (s2) represents the entire disk. The disk devices that you choose must not be shown as mounted partitions.

5. Enter the following commands to verify that the devices you identified are not already part of a disk group:

   
   

   Note: The following command displays information about VERITAS Volume Manager (VxVM) disks. If you use a different LVM, then refer to the appropriate documentation for information about determining which disk devices it is managing.

   
   

   # /usr/sbin/vxdiskconfig
   # /usr/sbin/vxdisk list
   
   

   The vxdisk list command identifies the disk devices that are already configured in a disk group. The word online in the STATUS column also identifies disks that have been initialized and placed under VxVM control. The word error in the STATUS column identifies disks that are not initialized.

   The disk devices that you choose must not be in an existing disk group.

6. If the disk devices that you want to use are not initialized, then enter a command similar to the following to initialize each disk:

   # /usr/sbin/vxdiskadd cxtydz
   
   

7. To create a shared disk group, enter a command similar to the following, specifying all of the disks that you want to add to the group:

   # /usr/sbin/vxdg -s init diskgroup diskname=devicename ...
   
   

   In this example:

   • -s indicates that you want to create a shared disk group

   • diskgroup is the name of the disk group that you want to create, for example, oradg

   • diskname is an administrative name that you assign to a disk, for example orad01

   • devicename is the device name, for example, c1t0d0

Creating Raw Logical Volumes in the New Disk Group

To create the required raw logical volumes in the new disk group:

1. Choose a name for the database that you want to create.

   The name that you choose must start with a letter and have no more than four characters, for example, orcl.

2. Identify the logical volumes that you must create.

   Table 3-3 lists the number and size of the logical volumes that you must create for database files.

   Table 3-3 Raw Logical Volumes Required for Database Files on Solaris

   Number	Size (MB)	Purpose and Sample Logical Volume Name
   1	500	SYSTEM tablespace: dbname_system_raw_500m
   1	300 + (Number of instances * 250)	SYSAUX tablespace: dbname_sysaux_raw_800m
   Number of instances	500	UNDOTBSn tablespace (One tablespace for each instance, where n is the number of the instance): dbname_undotbsn_raw_500m
   1	250	TEMP tablespace: dbname_temp_raw_250m
   1	160	EXAMPLE tablespace: dbname_example_raw_160m
   1	120	USERS tablespace: dbname_users_raw_120m
   2 * number of instances	120	Two online redo log files for each instance (where n is the number of the instance and m is the log number, 1 or 2): dbname_redon_m_raw_120m
   2	110	First and second control files: dbname_control{1|2}_raw_110m
   1	5	Server parameter file (SPFILE): dbname_spfile_raw_5m
   1	5	Password file: dbname_pwdfile_raw_5m

   
   
   
   

   Note: For RAC installations, Solaris Volume Manager volumes or partitions are not currently supported for Oracle Clusterware or database file storage.

   
   

3. To create the logical volume for the Oracle Cluster Registry, enter a command similar to the following:

   # /usr/sbin/vxassist -g diskgroup make ora_ocr_raw_100m 100m user=root \
    group=oinstall mode=640
   
   

   In this example, diskgroup is the name of the disk group you created previously, for example, oradg.

4. To create the required logical volumes, enter commands similar to the following:

   # /usr/sbin/vxassist -g diskgroup make volume size user=oracle \
    group=dba mode=660
   
   

   In this example:

   • diskgroup is the name of the disk group that you created previously, for example oradg

   • volume is the name of the logical volume that you want to create

     Oracle recommends that you use the sample names shown in the previous table for the logical volumes. Substitute the dbname variable in the sample logical volume name with the name you chose for the database in step 1.

   • size is the size of the logical volume, for example, 500m represents 500 MB

   • user=oracle group=dba mode=660 specifies the owner, group, and permissions on the volume

     Specify the Oracle software owner user and the OSDBA group for the user and group values (typically oracle and dba).

   The following example shows a sample command used to create an 800 MB logical volume in the oradg disk group for the SYSAUX tablespace of a database named test:

   # /usr/sbin/vxassist -g oradb make test_sysaux_5800m 5800m \
   user=oracle group=dba mode=660
   
   

Deporting the Disk Group and Importing It on the Other Cluster Nodes

To deport the disk group and import it on the other nodes in the cluster:

1. Deport the disk group:

   # /usr/sbin/vxdg deport diskgroup
   
   

2. Log into each cluster node and complete the following steps:

   1. Enter the following command to cause VxVM to examine the disk configuration:

      # /usr/sbin/vxdctl enable
      
      

   2. Import the shared disk group:

      # /usr/sbin/vxdg -s import diskgroup
      
      

   3. Start all logical volumes:

      # /usr/sbin/vxvol startall
      
      

3.6.2 Creating the Database Configuration Assistant Raw Device Mapping File

To allow Database Configuration Assistant to identify the appropriate raw device for each database file, you must create a raw device mapping file, as follows:

1. Set the ORACLE_BASE environment variable to specify the Oracle base directory that you identified or created previously:

   • Bourne, Bash, or Korn shell:

     $ ORACLE_BASE=/u01/app/oracle ; export ORACLE_BASE
     
     

   • C shell:

     % setenv ORACLE_BASE /u01/app/oracle
     
     

2. Create a database file subdirectory under the Oracle base directory and set the appropriate owner, group, and permissions on it:

   # mkdir -p $ORACLE_BASE/oradata/dbname
   # chown -R oracle:oinstall $ORACLE_BASE/oradata
   # chmod -R 775 $ORACLE_BASE/oradata
   
   

   In this example, dbname is the name of the database that you chose previously.

3. Change directory to the $ORACLE_BASE/oradata/dbname directory.

4. Edit the dbname_raw.conf file in any text editor to create a file similar to the following:

   
   

   Note: The following example shows a sample mapping file for a two-instance RAC cluster.

   
   

   system=/dev/vx/rdsk/diskgroup/dbname_system_raw_500m
   sysaux=/dev/vx/rdsk/diskgroup/dbname_sysaux_raw_5800m
   example=/dev/vx/rdsk/diskgroup/dbname_example_raw_160m
   users=/dev/vx/rdsk/diskgroup/dbname_users_raw_120m
   temp=/dev/vx/rdsk/diskgroup/dbname_temp_raw_250m
   undotbs1=/dev/vx/rdsk/diskgroup/dbname_undotbs1_raw_500m
   undotbs2=/dev/vx/rdsk/diskgroup/dbname_undotbs2_raw_500m
   redo1_1=/dev/vx/rdsk/diskgroup/dbname_redo1_1_raw_120m
   redo1_2=/dev/vx/rdsk/diskgroup/dbname_redo1_2_raw_120m
   redo2_1=/dev/vx/rdsk/diskgroup/dbname_redo2_1_raw_120m
   redo2_2=/dev/vx/rdsk/diskgroup/dbname_redo2_2_raw_120m
   control1=/dev/vx/rdsk/diskgroup/dbname_control1_raw_110m
   control2=/dev/vx/rdsk/diskgroup/dbname_control2_raw_110m
   spfile=/dev/vx/rdsk/diskgroup/dbname_spfile_raw_5m
   pwdfile=/dev/vx/rdsk/diskgroup/dbname_pwdfile_raw_5m
   
   

   Use the following guidelines when creating or editing this file:

   • Each line in the file must have the following format:

     database_object_identifier=raw_device_path
     
     

   • For a single-instance database, the file must specify one automatic undo tablespace data file (undotbs1), and at least two redo log files (redo1_1, redo1_2).

   • For a RAC database, the file must specify one automatic undo tablespace data file (undotbsn) and two redo log files (redon_1, redon_2) for each instance.

   • Specify at least two control files (control1, control2).

   • To use manual instead of automatic undo management, specify a single RBS tablespace data file (rbs) instead of the automatic undo management tablespace data files.

5. Save the file, and note the file name that you specified.

6. If you are using raw devices for database storage, then set the DBCA_RAW_CONFIG environment variable to specify the full path to the raw device mapping file:

   Bourne, Bash, or Korn shell:

   $ DBCA_RAW_CONFIG=$ORACLE_BASE/oradata/dbname/dbname_raw.conf
   $ export DBCA_RAW_CONFIG
   
   

   C shell:

   $ setenv DBCA_RAW_CONFIG=$ORACLE_BASE/oradata/dbname/dbname_raw.conf