Oracle 11g: Use Direct NFS for Datafiles

Oracle 11g (11.1.1) : Use Direct NFS for Datafiles: -

With Oracle Database 11g release 1 (11.1), instead of using the operating system kernel NFS client, you can configure Oracle Database to access NFS V3 servers directly using an Oracle internal Direct NFS client.

To enable Oracle Database to use Direct NFS, the NFS file systems must be mounted and available over regular NFS mounts. The mount options used are not relevant, as Direct NFS manages settings after installation.

You can use optional oranfstab (in eighter/etc or to $ORACLE_HOME/dbs.) to specify additional paths for a mount point.   

Direct NFS determines mount point settings to NFS storage devices based on the configurations in /etc/mtab, which are changed with configuring the /etc/fstab file.
Direct NFS searches for mount entries in the following order:

1. $ORACLE_HOME/dbs/oranfstab
2. /etc/oranfstab
3. /etc/mtab

Direct NFS uses the first matching entry found.

Direct NFS 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 reissues I/O commands over any remaining paths

Complete the following procedure to enable Direct NFS:

1. Create an oranfstab file
2. use an ODM library, libnfsodm11.so, to enable Direct NFS

1. Sample oranfstab file

server:  MyDataServer1
path:  132.34.35.12
path:  132.34.35.13
export: /vol/oradata1 mount: /mnt/oradata1
 
server: MyDataServer2
path:  NfsPath1
path:  NfsPath2
path:  NfsPath3
path:  NfsPath4
export: /vol/oradata2 mount: /mnt/oradata2
export: /vol/oradata3 mount: /mnt/oradata3
export: /vol/oradata4 mount: /mnt/oradata4
export: /vol/oradata5 mount: /mnt/oradata5

2. Steps to use ODM NFS Library.

1. Change directory to $ORACLE_HOME/lib.
2. Enter the following commands:
   

   mv libodm11.so libodm11.so_stub
   ln -s libnfsodm11.so libodm11.so