{"id":4513,"date":"2022-08-10T07:00:00","date_gmt":"2022-08-10T04:00:00","guid":{"rendered":"https:\/\/www.dataplatform.gr\/?p=4513"},"modified":"2023-11-05T21:37:30","modified_gmt":"2023-11-05T18:37:30","slug":"pos-energopoioyme-to-oracle-direct-nfs-gia-ayximeno-per","status":"publish","type":"post","link":"https:\/\/www.dataplatform.gr\/en\/pos-energopoioyme-to-oracle-direct-nfs-gia-ayximeno-per\/","title":{"rendered":"How to enable Oracle Direct NFS for increased performance between Oracle Database and NFS Shares"},"content":{"rendered":"

In this article we will see how to activate it Direct NFS<\/code> for connectivity Oracle Database<\/strong> with NFS Servers<\/strong>. When we activate it, the communication between the Oracle Database and NFS Servers takes place directly, without involving the kernel of the operating system, improving the performance at the I\/O level as well as the rest of the resources (CPU, RAM). Supports parallel I\/O<\/em>, asynchronous I\/O<\/em> and many security options.<\/p>\n\n\n\n

It gets the information about NFS Shares from \/etc\/fstab<\/code> (mtab).<\/p>\n\n\n\n

The footsteps<\/h2>\n\n\n\n

We create the folders with the oracle user as owner and the following permissions:<\/p>\n\n\n\n

su root\nmkdir -p \/oracle\/nfs\nmkdir -p \/oracle\/oradata\nmkdir -p \/oracle\/fra\nchown -R oracle:oinstall \/oracle\/nfs\nchown -R oracle:oinstall \/oracle\/oradata\nchown -R oracle:oinstall \/oracle\/fra\nchmod -R 775 \/oracle\/nfs\nchmod -R 775 \/oracle\/oradata\nchmod -R 775 \/oracle\/fra<\/pre>\n\n\n\n
To be sure that the rights to the NFS Server will not be cut, we go to the exports file and add a record for each NFS Share as below:<\/p>\n\n\n\n
vi \/etc\/exports<\/pre>\n\n\n\n
\/oracle\/nfs         *(rw,sync,no_wdelay,insecure_locks,no_root_squash)\n\/oracle\/oradata         *(rw,sync,no_wdelay,insecure_locks,no_root_squash)\n\/oracle\/fra         *(rw,sync,no_wdelay,insecure_locks,no_root_squash)<\/code><\/pre>\n\n\n\n
Then we restart the NFS service:<\/p>\n\n\n\n
chkconfig nfs on\nservice nfs restart<\/code><\/pre>\n\n\n\n
We add to the file \/etc\/fstab<\/code> one entry for each NFS Share so that they mount themselves when each machine starts:<\/p>\n\n\n\n
su root\n\nvi \/etc\/fstab<\/pre>\n\n\n\n
win-nfs:\/nfs \/oracle\/nfs  nfs rw,bg,hard,nointr,tcp,vers=3,timeo=600,rsize=32768,wsize=32768,actimeo=0  0 0\nwin-nfs:\/oradata \/oracle\/oradata  nfs rw,bg,hard,nointr,tcp,vers=3,timeo=600,rsize=32768,wsize=32768,actimeo=0  0 0\nwin-nfs:\/fra \/oracle\/fra  nfs rw,bg,hard,nointr,tcp,vers=3,timeo=600,rsize=32768,wsize=32768,actimeo=0  0 0\n<\/code><\/pre>\n\n\n\n
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01<\/figcaption><\/figure>\n\n\n\n
Now we are ready to mount them:<\/p>\n\n\n\n
mount \/oracle\/nfs\nmount \/oracle\/oradata\nmount \/oracle\/fra<\/pre>\n\n\n\n
If we want to give specific other options (e.g. Kerberos security option) beyond what it has in \/etc\/fstab<\/code> then we can create the file $ORACLE_HOME\/dbs\/oranfstab<\/code> which overrides the \/etc\/fstab<\/code>:<\/p>\n\n\n\n
vi $ORACLE_HOME\/dbs\/oranfstab<\/pre>\n\n\n\n
We declare the NFS Server with its IP, NFS protocol and NFS Shares:<\/p>\n\n\n\n
server: win-nfs           # nfs server hostname\npath: 172.25.94.95        # nfs server ip\nnfs_version: nfsv3\nexport: \/nfs mount: \/oracle\/nfs\nexport: \/oradata mount: \/oracle\/oradata\nexport: \/fra mount: \/oracle\/fra<\/pre>\n\n\n\n
From Oracle Database 12c onwards Direct NFS enabled by default<\/strong> alone. If it is not already enabled and we want to enable it, we run the following:<\/p>\n\n\n\n
cd $ORACLE_HOME\/rdbms\/lib\nmake -f ins_rdbms.mk dnfs_on<\/pre>\n\n\n\n
Accordingly if we want to disable it:<\/p>\n\n\n\n
cd $ORACLE_HOME\/rdbms\/lib\nmake -f ins_rdbms.mk dnfs_off<\/pre>\n\n\n\n
<\/p>\n\n\n\n
How do we check if it's activated?<\/h2>\n\n\n\n
To see that it has been activated when we create the database we run the following select, to see if it will bring records:<\/p>\n\n\n\n
select * from v$dnfs_servers;<\/pre>\n\n\n\n
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02<\/figcaption><\/figure>\n\n\n\n
We can also see the files that use Direct NFS with the following query:<\/p>\n\n\n\n
select * from v$dnfs_files;<\/pre>\n\n\n\n
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03<\/figcaption><\/figure>\n\n\n\n
Another way to see if Direct NFS is enabled is to look at the alert log<\/code> of Oracle Database when it starts if it displays the message:<\/p>\n\n\n\n
Oracle instance running with ODM: Oracle Direct NFS ODM Library Version 3.0<\/code><\/pre>\n\n\n\n
But if it shows us the following error:<\/p>\n\n\n\n
Direct NFS: please check that oradism is setuid<\/code><\/pre>\n\n\n\n
We should change the owner to root<\/code> and the permissions on the file oradism<\/code>:<\/p>\n\n\n\n
chown root:oinstall $ORACLE_HOME\/bin\/oradism\n\nchmod 4750 $ORACLE_HOME\/bin\/oradism<\/pre>\n\n\n\n
<\/p>\n\n\n\n
Sources:<\/h2>\n\n\n\n