Oracle Direct NFS(DNFS) Configuration

Direct NFS(DNFS) has been introduced from Oracle 11g. It integrates the NFS client functionality directly in the Oracle software. With DNFS Oracle can optimize the I/O path between Oracle and the NFS server providing significantly superior performance. It simplifies, and in many cases automates, the performance optimization of the NFS client configuration for database workloads. In addition, it can be implemented for multipathing over four parallel ports, independently from any switches, NIC bonding or teaming.

Environment:

NFS Server: ocm (192.168.1.252)
NFS Client: mentor (192.168.1.251)
Share dir: /u01/share
Mount point: /nfs

Make sure host name ocm and mentor are resolvable. If not add host entry on /etc/hosts file.
192.168.1.251 mentor mentor.localdomain
192.168.1.252 ocm ocm.localdomain

Create a NFS setup and mount the NFS on the local server.

yum -y install nfs-utils nfs-utils-lib

Create share point

mkdir /u01/share

Add following entry on /etc/export

cat >> /etc/exports

/u01/share 192.168.1.251(rw,async,no_wdelay,insecure,root_squash,insecure_locks,sec=sys,anonuid=1024,anongid=100)

Start nfs service on server

/etc/init.d/nfs start

NFS Client:

Create mount point on the nfs Client

mkdir /nfs

Add following entry on nfs client.

ocm:/u01/share /nfs   nfs   rw,bg,hard,nointr,tcp,vers=3,timeo=600,rsize=32768,wsize=32768,actimeo=0  0 0

Mount nfs share.

mount /nfs

Enable DNFS

shutdown the Oracle database.

shutdown immediate

Change directory to ORACLE_HOME/rdbms/lib and execute make command

cd $ORACLE_HOME/rdbms/lib

make -f ins_rdbms.mk dnfs_on

Start Oracle database.

startup

Oracle binary file oradism should owned by root and has setuid verify with command below.

cd $ORACLE_HOME/bin

ls -l oradism

-rwsr-x---. 1 root oinstall 71790 Aug 24  2013 oradism

If oradism has wrong permission or ownership correct it as follows

chown root:oinstall oradism

chmod 4755 oradism

Configure oranfstab file

cd $ORACLE_HOME/dbs

cat > oranfstab 

server: ocm

local: 192.168.1.251

path: 192.168.1.252

export: /u01/share mount: /nfs

Server = name of the server this name may be anything

local = IP address of the client

Path = IP address of the server

export = Path exported from nfs server

mount = Mount point on the nfs Client

Create a directory on the shared location to place the oracle datafiles. Make sure permission and ownership of the directory is oracle.

cd /u01/share/

ls

mkdir oradata

chown -R 1001:1001 oradata/

Still following SQL command will return no rows selected. To enable and configure DNFS UP we have to create a tablespace on the shared drive.

select * from v$dnfs_servers;

select * from v$dnfs_files;

Create tablespace on the nfs directory.

Create tablespace tbs_dnfs

datafile '/nfs/oradata/tbs_dnfs01.dbf' 

size 10m;

We can check alert log and find that the DNFS is UP now.

Direct NFS: channel id [0] path [192.168.1.252] to filer [ocm] via local [192.168.1.251] is UP

Direct NFS: channel id [1] path [192.168.1.252] to filer [ocm] via local [192.168.1.251] is UP

Once tablespace is created Following SQL will returns the output

select * from v$dnfs_servers;

select * from v$dnfs_files;

To disable DNFS

Change directory to ORACLE_HOME/rdbms/lib and execute make command with dnfs_off

cd $ORACLE_HOME/rdbms/lib

make -f ins_rdbms.mk dnfs_off