3 Configuring Oracle Clusterware and Oracle Database Storage

3.1.1 Overview of Storage Options

Use the information in this overview to help you select your storage option.

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3.1.2 Checking for Available Shared Storage with CVU

To check for all shared file systems available across all nodes on the cluster on a supported shared file system, use the following command:

/mountpoint/crs/Disk1/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/crs/Disk1/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/crs/Disk1/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 one of the following must be true:

  • The disks used for the file system are on a highly available storage device, (for example, a RAID device that implements file redundancy)

  • At least two file systems are mounted, and use the features of Oracle Database 10g Release 2 (10.2) to provide redundancy for the OCR.

  In addition, if you put the OCR and voting disk files on a shared file system, then that shared files system must be a shared QFS file system, and not a globally mounted UFS or VxFS file system.

• If you intend to use a shared file system to store database files, then 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. You can also configure shared file systems for the Oracle Database and recovery files.

To create directories for the Oracle Clusterware files on separate file systems from 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. Ensure 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 512 MB of free disk space (one OCR and one voting disk, with external redundancy)
   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 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 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 free 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 should 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 installing the starter database:

   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.

3.5.2 Configuring Database File Storage on ASM and Raw Devices

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

• To use ASM with raw partitions, you must create sufficient partitions for your data files, and then bind the partitions to raw devices.

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

Use the following procedure to configure disks:

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

2. To create or identify the disk slices (partitions) that you want to include in the Automatic Storage Management disk group:

   1. To list the disks attached to the system, 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).

   2. Enter the number corresponding to the disk that you want to use.

   3. Use the fdisk command to create a Solaris partition on the disk if one does not already exist.

      Solaris fdisk partitions must start at cylinder 1, not cylinder 0. If you create an fdisk partition, then you must label the disk before continuing.

   4. Enter the partition command, followed by the print command to display the partition table for the disk that you want to use.

   5. If necessary, create a single whole-disk slice, starting at cylinder 1.

      Note:

      To prevent Automatic Storage Management from overwriting the partition table, you cannot use slices that start at cylinder 0 (for example, slice 2).

   6. Make a note of the number of the slice that you want to use.

   7. If you modified a partition table or created a new one, then enter the label command to write the partition table and label to the disk.

   8. Enter q to return to the format menu.

   9. If you have finished creating slices, then enter q to quit from the format utility. Otherwise, enter the disk command to select a new disk and repeat steps b to g to create or identify the slices on that disks.

3. If you plan to use existing slices, then enter the following command to verify that they are not mounted as file systems:

   # df -h
   
   

   This command displays information about the 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.

4. Enter commands similar to the following on every node to change the owner, group, and permissions on the character raw device file for each disk slice that you want to add to a disk group:

   # chown oracle:dba /dev/rdsk/cxtydzs6
   # chmod 660 /dev/rdsk/cxtydzs6
   
   

   In this example, the device name specifies slice 6.

   Note:

   If you are using a multi-pathing disk driver with Automatic Storage Management, then ensure that you set the permissions only on the correct logical device name for the disk.

5. If you also want to use raw devices for storage, then refer to "Configuring Database File Storage on Raw Devices". Otherwise, when you have completed creating and configuring ASM with raw partitions, proceed to Chapter 4, "Installing Oracle Clusterware"

3.5.3 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 to 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 if an existing Automatic Storage Management disk group exists, or to determine if 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 if 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.

3.7.1 Configuring Raw Partitions for Oracle Database File Storage

A partition is a slice defined on a disk or on a disk array volume. On SPARC systems, it can also be a soft partition created using Solaris Volume Manager.

To configure raw partitions for database files:

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. If necessary, install or configure the disks that you intend to use and restart the system.

3. If you want to use Solaris Volume Manager soft partitions, then refer to the Solaris Volume Manager documentation for information about how to create them.

   The previous table shows the number and size of the partitions that you require.

4. If you want to use disk slices, then follow these steps to create or identify the required disk slices:

   1. To list the disks attached to the system, 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).

   2. Enter the number corresponding to the disk that you want to use.

      Note:

      Ensure that the disk you choose is not being used for another purpose. For example, ensure that it is not being used as a component for a logical volume manager volume.

   3. Use the fdisk command to create a Solaris partition on the disk if one does not already exist.

      Solaris fdisk partitions must start at cylinder 1, not cylinder 0. If you create an fdisk partition, then you must label the disk before continuing.

   4. Enter the partition command, followed by the print command to display the partition table for the disk that you want to use.

   5. Identify or create slices for each of the partitions that you require.

      The previous table shows the number and size of the partitions that you require for database files.

      Note:

      To prevent the database files from overwriting the partition table, do not use slices that start at cylinder 0 (for example, slice 2).

   6. Make a note of the number of the slices that you want to use.

   7. If you modified a partition table or created a new one, then enter the label command to write the partition table and label to the disk.

   8. Enter q to return to the format menu.

   9. After you have finished creating slices, enter q to quit from the format utility.

5. If you plan to use existing partitions, then enter the following command to verify that they are not mounted as file systems:

   # df -h
   
   

   This command displays information about the 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. The device name for a Solaris Volume Manager partition is similar to /dev/md/dsk/dnnn, where dnnn is the soft partition name.

6. Enter commands similar to the following to change the owner, group, and permissions on the character raw device file for each partition:

   Note:

   If you are using a multi-pathing disk driver, then ensure that you set the permissions only on the correct logical device name for the partition.

   • Solaris Volume Manager soft partitions:

     # chown oracle:dba /dev/md/rdsk/d100
     # chmod 660 /dev/md/rdsk/d100
     
     

     Repeat this step for each node on the cluster.

   • Disk slices:

     # chown oracle:dba /dev/rdsk/cxtydzsn
     # chmod 660 /dev/rdsk/cxtydzsn
     
     

     Repeat this step for each node on the cluster.

7. Complete the procedure "Creating the Database Configuration Assistant Raw Device Mapping File".

3.7.2 Configuring Raw Logical Volumes for Database File Storage

On Solaris x86 (64-bit), Oracle Real Application Clusters is supported with Solaris Volume Manager and Sun Cluster.

On Solaris x86, Oracle Real Application Clusters is not supported with Solaris Volume Manager, and not supported on Sun Cluster for x86.

On Solaris SPARC (64-bit) systems, Oracle Real Application Clusters is supported with Oracle Clusterware. However, Solaris Volume Manager is not certified.

This section contains the following:

• Configuring VERITAS CVM for SPARC (64-BIT)

• Configuring Solaris Volume Manager

# metadb -c 3 -af /dev/dsk/cXtYdZs7 

3.7.3 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 rollback segment 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