Oracle database 11g on Windows 2008 R2 & later | ORA-12518 error

June 6, 2017

Hi guys

Recently I was approached by a party to migrate their 14+ years old mini ERP system that is client/server architecture to a new hardware. This legacy application has such a small footprint that, the export dump was hardly reaching 300Mbs in size after a full database export.


  1. OS: Windows 2003 SP3, 32-Bit
  2. Oracle Database: 10g Release 1
  3. Client side, Developer 6i with Patch 18
  4. Clients using Windows 7, 64-Bit with DLL hacks for running forms/reports based application


  1. Database upgrade to 11g R2 64-Bit, in order to maximize the performance and properly utilize the new hardware (HP DL380 g9 with 32GB memory and more than 1TB storage)

We’ve initiated the migration by testing all possible scenarios using ORACLE VirtualBox. Created a VM for Windows 2008 R2 server, Created both Windows 10 & Windows 7 SP1 VMs for client side testing. After thorough checking to insure that there were no technical errors, decided to move the solution to physical server. Throughout the testing using VMs we never changed any database parameters (not even CASE SENSITIVE logon), yet all clients were happily connecting and executing forms and reports as expected.

The following were performed on the physical server after installing & updating Windows Server 2008 R2

  1. Installed Developer Suite 6i
  2. Installed Oracle Database 11g r2 (, accommodating 40% the physical memory and set the memory management as automatic.
  3. Configured RMAN
  4. Imported specific users from the latest export dump

We tried to start the application from one of the clients and the application started & the queries were executed at lightning speed. Client exit from the application and tried to restart, hitting Oracle not found error!

All of a sudden from the smirks, panic took over all the parties involved. We shutdown the services, restarted. Client gets connected, and 2nd attempt returns the same error  ‘Oracle not found’

Again the client connects and trying to run the reports prompts them a popup windows asking for logon to database.

After cross checking between VMs and Physical server, we confirm that both the scenarios share the same database and client settings (totally missing the PROCESSES parameter). Yet the physical scenario was continuously falling victim to Oracle not found error

A quick googling brought to me a blog page that asked to check the number of processes parameter set in the database instance, which was 150 by default in our case. I have cross checked with the VM instance and found the value to be 200. I have to redo the exercises to figure out whether I have changed the parameter after creating the database using DBCA.

Next I ran the following SQL as root to figure out the max processes count registered by the database

select resource_name, current_utilization, max_utilization from v$resource_
limit where resource_name in (‘processes’,’sessions’);

which returned me the following:

—————————— ——————- —————

processes                                       47             175

sessions                                        54             173

Obviously, the max_utilization has crossed the default value of 150 processes & I changed the parameter with 450 using alter system command.

Alter system set processes=450 scope=spfile;

After altering the system, a shutdown immediate followed by startup has fixed nightmare.

Further readings has given me a fairly good idea that 11g R2 has not the above said issues related to number of processes, many other related to network stack.

So, if you are planning to setup 11g to work with Developer 6i, which is not certified as a combination by Oracle, be prepared to bite the silver bullet(S)



Install Oracle Database 11g R2 on Windows 8.x, Windows 10

April 25, 2014

Update: 9th October 2015

The installation procedure mentioned below are applicable for Windows 10 also. So enjoy! I just finished installing the 11G R2 64Bit database in my computer running Windows 10 64Bit professional.


I believe if someone is attempting to install Oracle database in a laptop or desktop machine, it is purely for limited development requirements or learning.

A many who are new to Oracle database may not able to install the software on many versions of Microsoft client OS like Windows 7 or 8 until certain levels of hacks are made.

Ignore what “I know everything” geeks screaming across tech forums, asking you questions like “DID YOU READ THE CERTIFICATION MATRIX”

You don’t have the time, neither do I.

Let us install the Oracle database 11g R2 this time on a Windows 8.1 (Update 1) dell laptop with following configuration 8GB memory, 1TB Hdd, Windows 8.1 update 1 64Bit Other oracle software installed

  1. Developer Suite 6i
  2. Developer Suite 10g

Download the installation files from Oracle repositories

  1. There are two files to download, a total of 2GB
  2. Extract the zip files and move the files inside a single folder

Once extracted, you have something like below

  1. Folder Now Switch to the second folder, which reads as “win64_11gR2_database_2of2”
  2. Open up the “components” folder (D:\Oracle11gR2_64Bit\win64_11gR2_database_2of2\database\stage\Components)
  3. There will be four sub-folders within “Components” folder, copy them to D:\Oracle11gR2_64Bit\win64_11gR2_database_1of2\database\stage\Components folder

That’s all. Just start the installation process. Make sure you have changed the virtual memory settings of your box prior the installation (If you already have developer suite 10g, you already changed it) Start the installation by executing “setup.exe” setup You will get one warning, about not meeting the recommended environment requirements (/me chuckles). We didn’t check the 32Bit version of Oracle Database 11g R2, however the method should be same. Hope you enjoyed another post from us

for Windows7bugs


Install Oracle Database 11g Enterprise Edition Release (64Bit) on Windows 8 Professional 64Bit

December 10, 2012



  1. Windows 8 Professional – 64Bit (i5 Processor, 8GB memory)
  2. Database 11g Enterprise Edition Release (64Bit)


Once you finished downloading the installation source from Oracle, extract the files using any available unzip utility.

Copy all the folders from “win64_11gR2_database_2of2\database\stage\Components” to

“win64_11gR2_database_1of2\database\stage\Components” folder to avoid warnings about missing components during installation. Oracle should fix it, right?

If your computer is a domain member, then

    1. Create a local user
    2. Add the user to “Administrator” group
    3. Logon as local user
    4. If you are installing Oracle on D:\ , right click and assign full rights to your account on that particular drive. Only applicable with Window7 and Windows 8

Start the installation, and you will be provided a warning. Refer the image below


Ignore it

Proceed with the installation

Ignore the update related warning also


Just follow the prompts and complete the installation. It should be a smooth sailing.

Prior trying to access the database, make sure you changed the sqlnet.ora file following

# sqlnet.ora Network Configuration File: D:\oracle\product\11.2.0\dbhome_1\network\admin\sqlnet.ora
# Generated by Oracle configuration tools.

# This file is actually generated by netca. But if customers choose to
# install “Software Only”, this file wont exist and without the native
# authentication, they will not be able to connect to the database on NT.




We will post more screen shots soon. Stay tuned!