Re: ORA-12500: TNS:listener failed to start a dedicated server process

Hari Om wrote:

> I have my Oracle DB on IBM AIX Server. I have installed my Client on
> WIn XP machine and I used to access my DB Server from my Win XP mc and
> it used to work fine.
>
> Today, all of a sudden - I could not log in to my Oracle DB Server -
> wonder why? It keeps on giving me "ORA-12500: TNS:listener failed to
> start a dedicated server process" Error" I have READ ALL the posting
> but still could'nt figure out.

Basically what is happening (ignoring running Oracle in "shared mode" using MTS):
- you open a connection to the listener
- the listener accepts and starts an Oracle process   on to service you (also called a shadow process) - the shadow process inherits the connection and serves   as your interface into Oracle

What is happening is that the listener is failing to start that shadow process for you.

> My LISTENER.ORA file is:

<snipped>

This is your listener.ora file on your client machine? If so, this file is not applicable. You are making a client connection from your machine to the AIX server running the Oracle listener. Thus, you need to have a look at the listener.ora (and log file) on the AIX server.

If this file is your AIX server's listener.ora, then it is wrong I think. You have FAT/NTFS file system names as the references to Oracle's home directory. Can you have that on AIX? (never even seen an AIX box myself)

Also, the listener is only listening on 127.0.0.1 - and will thus not accept connections from clients.

I think what you are doing here is making a localhost/loopback connection to the listener on _your_ machine - and this fails as you likely have no Oracle db running on your machine.

You need to fix your TNSNAMES.ORA. And spend some time reading up on the basic architecture of Oracle and get an idea of which config files are required on the client and what is required on the server - and how this hangs together.

--
Billy