Implementing Shared Application Tier Filesystem Using NFS

Implementing Shared Application Tier Filesystem Using NFS

A few posts ago I had discussed about the Shared APPL_TOPs and Shared Application Tier Filesystem feature in Oracle Application. While the ability to shared APPL_TOPs has been there for sometime, the feature of sharing the entire Application Tier Filesystem was introduced with 11.5.10.The difference between both being that while the shared APPL_TOP allowed sharing only of the application toip files among the nodes. In the Shared Application Tier filesystem the complete application tier file system along with the tech stacks are also shared among the nodes.

To implement a shared application tier filesystem we need top have a shared disk resource which is accessible to all the nodes which consist of Oracle Applications architecture. This shared disk can be in the form of a shared disk or an NFS mounted shared disk.In the current post I will blog about the steps involved in implementing a shared application tier file system using NFS on Redhat Linux.

System Configuration
Node_A (To be used for web server and forms server)

Node_B (To be used for db tier and concurrent manager and admin node)

Objective

To implement a shared application tier file system using an NFS mount and having a full install on Node_B and sharing the existing with Node_A.

Create OS Users

Note that is is necessary to have the same UID and GID for both the OS users on Node_A and Node_B.Also the user names must be the same so as not to have any file permission problems.

Create OS Users on Node_A
# useradd -g dba -d /home/applsam applsam

Create OS Users on Node_B
# useradd -g dba -d /home/orasam orasam

# useradd -g dba -d /home/applsam applsam

Create Directory Structure
I used the following directory structure for the installation, you may use your own and make sure that it is shared accordingly.

On Node_B

mkdir /s01/apps (to hold the application tier filesystem)

mkdir /s01/data (to hold the database tier filesystem)

Setup NFS Mount

Setup NFS mount to share the /s01/apps filesystem of Node_B  to Node_A. You must however NFS mount with the nolock option to avoid issues with autoconfig and adpatch.

On Node_B

Edit the exports file to add in the shared filesystem details

#vi /etc/exports

/s01/apps (rw) Node_A

Restart the NFS Service on Node_B

# service nfs restart

Shutting down NFS mountd:                                  [  OK  ]

Shutting down NFS daemon:                                  [  OK  ]

Shutting down NFS quotas:                                  [  OK  ]

Shutting down NFS services:                                [  OK  ]

Starting NFS services:                                     [  OK  ]

Starting NFS quotas:                                       [  OK  ]

Starting NFS daemon:                                       [  OK  ]

Starting NFS mountd:                                       [  OK  ]

On Node_A

Create a directory to hold the mount and do an NFS mount of the filesystem

mkdir /s01/apps

mount -t nfs Node_B:/s01/apps /s01/apps -o nolock

Starting the Installation

On Node_B

The installation is started on Node_B with the root user. Before that make sure you set up the path for your oracle inventory

Setup orainventory location

vi /etc/oraInst.loc

inventory_loc=/s01/oraInventory

inst_group=dba

During the rapidwiz installation screen you must choose a multi node install option and check the Share Application Tier Filesystem Option.

Choose the nodes where you wish to do a complete install and the nodes where you want to share the existing installation.

After post installation checks are complete you can proceed to the next node.
On Node_A

On Node_A since i have only one OS user (applsam) i start the installation form that user and source the config.txt file created as part of the installation done on Node_B.

Since Node_A is going to share the entire application tier filesystem from Node_B no installation will be required as such. However we run rapidwiz on Node_A to configure it to perform context value management and startup the configured services for that node.

Implementing Shared Application Tier Filesystem Using NFS