8 Oracle Database Postinstallation Tasks

8.3.2.1 Configuring the Accounts of Oracle Users

Update the startup files of the oracle user and the operating system accounts of Oracle users, specifying the appropriate environment variables in the environment file.

For the Bourne, Bash, or Korn shell, add the environment variables to the profile file for the Bash shell on Oracle Linux and Red Hat Enterprise Linux.

For the C shell, add the environment variables to the .login file.

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

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

When you enable fast recovery in the init.ora file, Oracle Database writes all RMAN backups, archive logs, control file automatic backups, and database copies to the fast recovery area. RMAN automatically manages files in the fast recovery area by deleting obsolete backups and archiving files no longer required for recovery.

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

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

Multiple databases can use the same fast recovery area. For example, assume you have created a fast recovery area disk group on disks with 150 GB of storage, shared by 3 different databases. You can set the size of the fast recovery for each database depending on the importance of each database. For example, if database1 is your least important database, database2 is of greater importance and database3 is of greatest importance, then you can set different DB_RECOVERY_FILE_DEST_SIZE settings for each database to meet your retention target for each database: 30 GB for database1, 50 GB for database2, and 70 GB for database3.

8.3.5.2 Creating the Fast Recovery Area Disk Group

To create a fast recovery file disk group:

1. Go to the Grid home bin directory, and start ASM Configuration Assistant (ASMCA), for example:

   $ cd /u01/grid/bin
   $ ./asmca
   

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

3. The Create Disk Groups window opens.

   In the Disk Group Name field, enter a descriptive name for the fast recovery area group. For example: FRA.

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

   In the Select Member Disks field, select eligible disks to be added to the fast recovery area, and click OK.

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

5. Click Exit.

8.4.1.1 Modifying the listener.ora File

If you are upgrading from a previous release of Oracle Database, Oracle recommends that you use the current release of Oracle Net listener instead of the listener from the previous release.

If you have referenced the previous Oracle home directory names in the static listener information, then these directory names must be modified before the listener.ora file can be used in the 12.1 environment.

To use the listener from the current release, copy the static service information from the listener.ora file from the previous release to the version of that file used by the new release.

For any database instances earlier than release 8.0.3, add static service information to the listener.ora file. Oracle Database releases later than release 8.0.3 do not require static service information.

8.4.1.2 Modifying the tnsnames.ora File

Unless you are using a central tnsnames.ora file, copy Oracle Net Services names and connect descriptors from the earlier release tnsnames.ora file to the version of that file used by the new release.

If necessary, you can also add connection information for additional database instances to the new file.

8.4.5.1 Configuring Pro*C/C++

Verify that the PATH environment variable setting includes the directory that contains the C compiler executable.

The following table shows the default directories and the appropriate command to verify the path setting of the compiler.

8.4.5.2 Configuring Pro*FORTRAN

Verify that the PATH environment variable setting includes the directory that contains the FORTRAN compiler executable.

The following table shows the default directories and the appropriate command to verify the path setting of the compiler.

8.4.10.1 About Direct NFS Client Configuration

With Oracle Database, instead of using the operating system kernel NFS client, you can configure Oracle Database to access NFS servers directly using an Oracle internal Direct NFS Client. The Direct NFS Client supports NFSv3, NFSv4 and NFSv4.1 protocols (excluding the Parallel NFS extension) to access the NFS server.

Direct NFS Client supports up to four network paths to the NFS server. The Direct NFS Client performs load balancing across all specified paths. If a specified path fails, then Direct NFS Client reissues I/O commands over any remaining paths.

Some NFS file servers require NFS clients to connect using reserved ports. If your filer is running with reserved port checking, then you must disable it for Direct NFS Client to operate. To disable reserved port checking, see your NFS file server documentation.

For NFS servers that restrict port range, you can use the insecure option to enable clients other than root to connect to the NFS server. Alternatively, you can disable Direct NFS Client as described in "Disabling Direct NFS Client."

8.4.10.2 About the oranfstab File and Direct NFS Client

Direct NFS Client uses either the configuration file $ORACLE_HOME/dbs/oranfstab or the operating system mount tab file /etc/mtab to find out what mount points are available. If oranfstab is not present, then by default Direct NFS Client servers mount entries found in /etc/mtab. No other configuration is required. You can use oranfstab to specify additional Oracle Database specific options to Direct NFS Client. For example, you can use oranfstab to specify additional paths for a mount point.

You can add a new oranfstab file specifically for Oracle Database, either in the path /etc or $ORACLE_HOME/dbs. When oranfstab is placed in $ORACLE_HOME/dbs, its entries are specific to a single database. However, when oranfstab is placed in /etc, then it is global to all Oracle databases, and can contain mount points for all Oracle databases.

8.4.10.3 Mounting NFS Storage Devices with Direct NFS Client

Direct NFS Client determines mount point settings to NFS storage devices based on the configurations in /etc/mtab. Direct NFS Client searches for the mount entries in the following order:

1. $ORACLE_HOME/dbs/oranfstab

2. /etc/oranfstab

3. /etc/mtab

Direct NFS Client uses the first matched entry as the mount point.

Oracle Database requires that mount points be mounted by the kernel NFS system even when served through Direct NFS Client.

If Oracle Database cannot open an NFS server using Direct NFS Client, then Oracle Database uses the platform operating system kernel NFS client. In this case, the kernel NFS mount options must be set up as defined in "Checking NFS Buffer Size Parameters". Additionally, an informational message is logged in the Oracle alert and trace files indicating that Direct NFS Client could not be established.

The Oracle database files available on the NFS server that are served by the Direct NFS Client are also accessible through the operating system kernel NFS client. The usual considerations for maintaining integrity of Oracle database files apply in this situation.

8.4.10.4 Checking NFS Buffer Size Parameters

If you use 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.

Direct NFS Client issues writes at wtmax granularity to the NFS server.

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

nfs_server:/vol/DATA/oradata /home/oracle/netapp nfs\
rw,bg,hard,nointr,rsize=32768,wsize=32768,tcp,actimeo=0,vers=3,timeo=600

8.4.10.5 Setting TCP Network Protocol Buffer for Direct NFS Client

By default, the network buffer size is set to 1 MB for TCP, and 2 MB for UDP. The TCP buffer size can set a limit on file transfers, which can negatively affect performance for Direct NFS Client users.

To check the current TCP buffer size, enter the following command:

# sysctl -a |grep -e net.ipv4.tcp_[rw]mem

The output of this command is similar to the following:

net.ipv4.tcp_rmem = 4096        87380   1048576
net.ipv4.tcp_wmem = 4096        16384   1048576

Oracle recommends that you set the value based on the link speed of your servers. For example, perform the following steps:

1. As root, use a text editor to open /etc/sysctl.conf, and add or change to the following:

   # net.ipv4.tcp_rmem = 4096        87380   4194304
   # net.ipv4.tcp_wmem = 4096        16384   4194304
   

2. Restart the network:

   # /etc/rc.d/init.d/network restart
   

8.4.10.6 Specifying Network Paths with the oranfstab File

Direct NFS Client can use up to four network paths defined in the oranfstab file for an NFS server. The Direct NFS Client performs load balancing across all specified paths. If a specified path fails, then Direct NFS Client reissues I/O commands over any remaining paths.

Use the following SQL*Plus views for managing Direct NFS Client in a single instance environment:

• v$dnfs_servers: Shows a table of servers accessed using Direct NFS Client.

• v$dnfs_files: Shows a table of files currently open using Direct NFS Client.

• v$dnfs_channels: Shows a table of open network paths (or channels) to servers for which Direct NFS Client is providing files.

• v$dnfs_stats: Shows a table of performance statistics for Direct NFS Client.

8.4.10.7 Enabling Direct NFS Client

Complete the following procedure to enable Direct NFS Client:

1. Create an oranfstab file with the following attributes for each NFS server to be accessed using Direct NFS Client:

   • Server: The NFS server name.

   • Path: Up to four network paths to the NFS server, specified either by IP address, or by name, as displayed using the ifconfig command on the filer.

   • Local: Up to four local paths on the database host, specified by IP address or by name, as displayed using the ifconfig command run on the database host.

   • Export: The exported path from the NFS server.

   • Mount: The corresponding local mount point for the exported volume.

   • Dontroute: Specifies that outgoing messages should not be routed by the operating system, but sent using the IP address to which they are bound. Note that this POSIX option sometimes does not work on Linux systems with multiple paths in the same subnet.

   • mnt_timeout: Specifies (in seconds) the time the Direct NFS Client should wait for a successful mount before timing out. This parameter is optional and the default timeout is 10 minutes (600).

   • nfs_version: Specifies the NFS protocol version that the Direct NFS Client uses. Possible values are NFSv3, NFSv4 and NFSv4.1. The default version is NFSv3. If you want to specify NFSv4.x, then you must set the nfs_version parameter accordingly in the oranfstab file.

   • management: Enables Direct NFS Client to use the management interface for SNMP queries. You can use this parameter if SNMP is running on separate management interfaces on the NFS server. The default value is the server parameter value.

   • community: Specifies the community string for use in SNMP queries. Default value is public.

   See Also:

   "Limiting Asynchronous I/O in NFS Server Environments" in Oracle Database Performance Tuning Guide

   Example 8-2 oranfstab file with two NFS server entries

   server: MyDataServer1
   local: 192.0.2.0
   path: 192.0.2.1
   local: 192.0.100.0
   path: 192.0.100.1
   nfs_version: nfsv3
   dontroute
   export: /vol/oradata1 mount: /mnt/oradata1
   
   server: MyDataServer2
   local: LocalPath1
   path: NfsPath1
   local: LocalPath2
   path: NfsPath2
   local: LocalPath3
   path: NfsPath3
   local: LocalPath4
   path: NfsPath4
   nfs_version: nfsv4
   dontroute
   export: /vol/oradata2 mount: /mnt/oradata2
   export: /vol/oradata3 mount: /mnt/oradata3
   export: /vol/oradata4 mount: /mnt/oradata4
   export: /vol/oradata5 mount: /mnt/oradata5
   management: MgmtPath1
   community: private
   

2. By default, Direct NFS Client is installed in a disabled state with single instance Oracle Database installations. To enable Direct NFS Client, complete the following steps:

   1. Change the directory to $ORACLE_HOME/rdbms/lib.

   2. Enter the following command:

      make -f ins_rdbms.mk dnfs_on
      

8.4.10.8 Disabling Direct NFS Client

Complete the following steps to disable Direct NFS Client:

1. Log in as the Oracle software installation owner, and disable Direct NFS Client using the following commands:

   cd $ORACLE_HOME/rdbms/lib
   make -f ins_rdbms.mk dnfs_off
   

2. Remove the oranfstab file.

8.4.10.9 Enabling HCC on Direct NFS Client

To enable Hybrid Columnar Compression (HCC) on Direct NFS Client, perform the following steps:

1. Ensure that SNMP is enabled on the ZFS storage server. For example:

   $ snmpget -v1 -c public server_name .1.3.6.1.4.1.42.2.225.1.4.2.0
   SNMPv2-SMI::enterprises.42.2.225.1.4.2.0 = STRING: "Sun Storage 7410"
   

2. If SNMP is enabled on an interface other than the NFS server, then configure oranfstab using the management parameter.

3. If SNMP is configured using a community string other than public, then configure oranfstab file using the community parameter.

4. Ensure that libnetsnmp.so is installed by checking if snmpget is available.