Main user for most of the oracle products, especially for Oracle Database installations is an oracle user account. Oracle-validated package does create such account automatically with proper group membership configuration and "random" unknown password. 

In Linux world (following good practice rules) we all have our own, personal and dedicated user accounts which belongs to the particular system groups. For example, employees performing DBA role within an organization would have an account which belongs to "dba", "wheel" and other custom groups. Most of the organizations are dealing with massive OS and database installations which also have "oracle" accounts configured, but always the password of the oracle account should stay unknown to all users. 

But how to switch to oracle user when we don't know the password? Simply – using power of sudo, su in combination with sudoers. 
But first particular account needs to be configured to have sufficient privileges to switch to oracle and other users either with or without providing their own (not root or oracle accounts' passwords) passwords when switching.

Imagine we are a dba within an organization and we have a new account "fred" created in Linux OS.

 
[root@test-host ~]# useradd -m -n fred
[root@test-host ~]# passwd fred
Changing password for user fred.
New UNIX password:
BAD PASSWORD: it is based on a dictionary word
Retype new UNIX password:
passwd: all authentication tokens updated successfully.
[root@test-host ~]# id fred
uid=54322(fred) gid=100(users) groups=100(users)
[root@test-host ~]#
 

As we can see user fred belongs to group "users" by default.

Let's make that user also belong to "dba" group:

 
[root@test-host ~]# usermod -g users -G dba fred 
[root@test-host ~]# id fred
uid=54322(fred) gid=100(users) groups=100(users),54322(dba)
[root@test-host ~]#
 

Now user fred belongs to the following groups: users, dba
Let's try to switch to oracle account using sudo:

In article Installing Oracle Linux in VMware virtual machine we covered installation of Oracle Linux 5U8 including oracle-validated package.

Now, our system is ready for Oracle database installation, and no additional configuration tasks is required at this moment.

Note: Most of the time we work with OS from remote locations and target servers are located in data centers or somewhere else.

In this tutorial we assume that our server is located in a remote location and we use remote access tools in order to connect to the Linux terminal, transfer installation packages, and run Oracle Universal Installer on our local (client) machine.

What we are going to show:

1. Downloading Oracle database 11g installation packages from Oracle websites

2. Installing local X-Server Xming to be able to display GUI applets from a remote server on our local desktop, like we were sitting in front of the server.

3. Connecting to Linux server using WinSCP and transferring installation packages.

4. Connecting to Linux server via SSH protocol using PuTTY  and reset password for oracle user (WinSCP and PuTTY how-to can be found here: Enter The Linux ).

5. Configure PyTTY session with port forwarding enabled to be able to display GUI windows via Xming server

6. Unpacking and running Oracle Universal Installer to install Oracle database software

7. Creating new Oracle database instance with Enterprise Manager Database Control

8. Testing our installation connecting to running database instance using the following tools:

• SqlPlus (general command line tool)
• Oracle SQLDeveloper – GUI Oracle database client
• Enterprise Manager Database Control 11g – web based powerful administration and monitoring tool

Let’s get started…

1. Download Oracle Database software installation package from Oracle Technology Network

We are going to download Linux 64bit version Oracle Database 11g Release 2 (11.2.0.1.0) for Linux x86-64 

• linux.x64_11gR2_database_1of2.zip
• linux.x64_11gR2_database_2of2.zip

2. Installing and running Xming X Server on Windows host

---

Xming will start minimized in system tray next to the system clock.

What is Oracle Linux?

Oracle Linux is an open source operating system available under the GNU General Public License (GPL) and is
available for free download .

Oracle Linux includes two kernels:

• Unbreakable Enterprise Kernel, tracks mainline Linux kernel closely, and offers the latest features and
  tested performance and stability
• The Red Hat Compatible Kernel, compiled directly from Red Hat Enterprise Linux source

In this tutorial we are going to install Oracle Linux 5 Update 8 (64 bit) prepared to install Orcale Database 11g on it.

What we are going to cover:

1. New virtual image creation

2. Linux Installation using Linux ISO Image downloaded from Oracle eDelivery website
 

1. cut - Removes sections from each line of files.

Prints selected parts of lines from each file to standard output.
Default separator is a "Tab" sign.

Imagine we've got a file file_numbers.txt, which consist of three columns:

col_1 col_2 col_3
 
one two three
 
four five six
 
seven eight nine
 
ten eleven twelve
 

In the following example cut will return only column (col_2):

cut -f2 file_numbers.txt
 
col_2
two
five
eight
eleven
 

in the next example cut will return columns 2 and 3:

cut -f1,3 file_numbers.txt
 
col_1 col_3
one three
four six
seven nine
ten twelve
 

There os few more options described in man pages. Let's take a look at two of them:

- c --characters=LIST select only these characters

- d --delimiter=DELIM use DELIM instead of TAB for field delimiter

In below example we will use "space" mark as a separator (-d " ")

NOTE: an input delimiter may be specified only when operating on fields

How To Setup SSH equivalency, password-less SSH between multiple hosts.

• We have host-1 and host-2 - two Linux hosts.
• User "Trinity" exists on both hosts
• We want to setup password-less authentication from host-1 to host-2 and the other way around
• We are going to introduce two ways of achieving that (there is more ofcourse :)

[Trinity@host-1 ~]$ ssh-keygen -t dsa
Generating public/private dsa key pair.
Enter file in which to save the key (/home/Trinity/.ssh/id_dsa):
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /home/Trinity/.ssh/id_dsa.
Your public key has been saved in /home/Trinity/.ssh/id_dsa.pub.
The key fingerprint is:
3f:8e:3d:1b:47:8d:49:dc:89:68:du:22:2e:e1:f8:4b Trinity@host-1.local
 
[Trinity@host-1 ~]$ cat ~/.ssh/id_dsa.pub | ssh Trinity@host-2 'cat - >> ~/.ssh/authorized_keys'
Trinity@host-2's password:   

#Now let's connect to host-2, and this time password would not be required:
 
[Trinity@host-1 ~]$ ssh host-2
Last login: Thu Dec 32 25:61:66 2037 from 11.69.33.255
 
Hello! Follow the white rabbit... 
My Lab_067 *** Linux Rulezz ***
host host-2.local * Linux

[Trinity@host-2 ~]$ hostname
host-2.local
 

 
[Trinity@host-1 ~]$ ssh-copy-id -i ~/.ssh/id_dsa.pub Trinity@host-2
30
Trinity@host-2's password:  
Now try logging into the machine, with "ssh 'Trinity@host-2'", and check in:    

.ssh/authorized_keys    

to make sure we haven't added extra keys that you weren't expecting.  

[Trinity@host-1 ~]$ ssh host-2  
Last login: Thu Dec 33 26:16:69 2037 from 11.69.33.255  
Hello! Follow the white rabbit...  
My Lab_067 *** Linux Rulezz *** 
host host-2.local * Linux  

[Trinity@host-2 ~]$ hostname  
host-2.local
 

1. Introduction

Oracle Real Application Clusters (Oracle RAC) enables an Oracle database to run across a cluster of servers, providing fault tolerance, performance, and scalability with no application changes necessary. Oracle RAC provides high availability for applications by removing the single point of failure with a single server.

This guide describes how to install, configure, and manage Oracle RAC, Oracle Clusterware, and Oracle Automatic Storage Management (Oracle ASM). It provides examples for how you could deploy Oracle RAC on a two-node cluster, using the Oracle Linux operating system. This installation guide assumes several points, see below.

 

Last Updated (Monday, 14 May 2012 12:45)

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