ORA-01034: ORACLE not available ORA-27101: shared memory realm does not exist Linux-x86_64 Error: 2: No such file or directory

I get the following issue when connecting to Oracle DB via SID:

$sqlplus myusername/mypassword@sid
SQL*Plus: Release 11.2.0.3.0 Production on Wed Aug 22 00:35:56 2012
Copyright (c) 1982, 2011, Oracle. All rights reserved.

ERROR:
ORA-01034: ORACLE not available
ORA-27101: shared memory realm does not exist
Linux-x86_64 Error: 2: No such file or directory
Process ID: 0
Session ID: 0 Serial number: 0

This server is running Oracle 11.2.0.3 on Redhat 6 64bit.

I made a change in /opt/oracle/112/network/admin/tnsnames.ora

# tnsnames.ora Network Configuration File: /opt/oracle/112/network/admin/tnsnames.ora
# Generated by Oracle configuration tools.

PSDS =
    (DESCRIPTION =
        (ADDRESS = (PROTOCOL = TCP)(HOST = oracle.abc.com)(PORT = 1521))
        (CONNECT_DATA =
            (SERVER = DEDICATED)
            #(SERVICE_NAME = sid)
            (SID=sid)
        )
    )

Then it worked!

Using PHP5-FPM With Apache2 On Ubuntu 12.04 LTS

http://www.howtoforge.com/using-php5-fpm-with-apache2-on-ubuntu-12.04-lts

How to Install Munin on CentOS

Munin is a monitoring tool for servers. It uses RRDtool to log and graph data from your servers. The plugin API is very easy to grasp. Actually, I haven’t read the API documentation yet. I just looked at the output of the plugins and it looks easy to achieve. The data can be accessed through the web.

This guide will walk you through installing and configuring Munin on CEntOS 4.3/4.4 x86. The steps are pretty much the same for later releases of CEntOS, Red Hat, Fedora [Core] and/or Red Hat-based installations.

Munin works by polling your servers for the data hence two applications, Munin and Munin Node. The former periodically gathers data (cronned) and the latter serves the data to the former. Please refer to the following for our example configuration. You can make up a domain if you want Munin to group your servers similar to the live demo.

Munin “Graph Server” – alpha.sample.net (192.168.1.1)
A Munin Node – bravo.sample.net (192.168.1.2)