Install Oracle RAC 10g on Oracle Enterprise Linux Using VMware Server

by Vincent Chan

Evaluate Oracle Real Application Clusters 10g Release 2 on Oracle Enterprise Linux for free, using virtual machines

Published January 2007

Introduced at Oracle OpenWorld 2006 in October, Oracle Unbreakable Linux aims to offer enterprise-class support services for Red Hat Linux, quicker bug fixes, and a significantly lower support prices. And Oracle’s own Enterprise Linux, which is based on Red Hat Advanced Server Release 4 (Update 4) with additional bug fixes, is freely available for download.

As a side effect, it is now possible to evaluate Oracle Real Application Clusters (RAC) 10g running on Red Hat Advanced Server on home computers at no cost whatsoever, using VMware Server—a free virtualization environment from VMware.

Continua”How to install Oracle Rac 10 On Oracle Enterprise Linux using VMWare Server”

How do you install and use rsync to synchronize files and directories from one location (or one server) to another location? - A common question asked by new sys admin.

rsync is a free software computer program for Unix and Linux like systems which synchronizes files and directories from one location to another while minimizing data transfer using delta encoding when appropriate. An important feature of rsync not found in most similar programs/protocols is that the mirroring takes place with only one transmission in each direction.

So what is unique about rsync?

It can perform differential uploads and downloads (synchronization) of files across the network, transferring only data that has changed. The rsync remote-update protocol allows rsync to transfer just the differences between two sets of files across the network connection.

Continua”Using Rsync to Synchronize files”

Wget is a network utility to retrieve files from the Web using http and
ftp, the two most widely used Internet protocols . It works non-interactively, so it will
work in the background, after having logged off. The program supports recursive retrieval
of web-authoring pages as well as ftp sites. You can use wget
to make mirrors of archives and home pages or to travel the Web like a WWW robot.

Recently i needed to download a bunch of RPM files for the kolab.org site that were on a directory. The install guide for the kolab server demanded to have all the rpm’s listed on that directory to be able to run the install. I didn’t want to download each rpm by pasting the URL and then using wget to download the file. I remembered that there was a way to mirror a web directory including all files inside the directory with wget but i forgot the correct syntax and I came across this guide.

Here is the command

[root@nycentos sources]# wget –mirror -w 2 -P /root/kolab/ http://max.kde.org:8080/mirrors/www.erfrakon.de/projects/kolab/download/ftp.kolab.org/server/release/kolab-server-2.0.4/sources/

and here is the guide.

Continua”Mirror a site using wget .”

This is step-by-step how-to install and setup your OpenLDAP server on FC4. This howto also covers managing the LDAP users and GUI/Web tools for managing LDAP users. And for the bonus, I’ll show you how to automatically mount users home folders (with NFS), so they can access theyr home folders from any machine on the network that they logon to.

What is LDAP

LDAP is a software protocol for enabling anyone to locate organizations, individuals, and other resources such as files and devices in a network, whether on the public Internet or on a corporate intranet. LDAP is a “lightweight” (smaller amount of code) version of Directory Access Protocol (DAP), which is part of X.500, a standard for directory services in a network.

Continua”Installing and maintaining an OpenLDAP server for you network”

Virtualization is a method of using "logical" computers as opposed to using physical ones. To simplify my last statement, this means that you can install a virtual computer to run on your physical box as if it were an application. While there are a few virtualization software vendors in the market, the 2 main players are VMware

Continua”Setting up a Lab to learn Hacking and Security using VMWare”

For some time i have been playing with the VMWare player , a tool available for free from vmware.
The tool allows you to run virtual machines without you having to buy VMWare workstation.

http://www.vmware.com/products/player/

The only problem is that you can only use existing machines. You can’t create machines.
Still there are some Virtual Machines for free that you can try and test. They are a great way to test linux servers and configure stuff on them. For example I build an email server at work running qmail and it is actually working sending and receiving email, but the only problem I have so far is keeping the time on my virtual machine.

The time runs either too fast or too slow. one of the issues is that you need the VMWare tools that come with the VMWare workstation to keep the time synchronized with the guest virtual machine.

I tried other hackes but the clock always runs very slow.

I did some googling and even after using the VMWare tools some people are still having issues keeping time with Linux virtual machines running the 2.6 kernel.

here is some info from VMWare regarding time sync.

Continua”A Virtual Lab with VMWare Player”

Linux has become a synonym for Networking. It is being used both
in office and home environments as file, print, e-mail,
application server and also it is increasingly being used as
Proxy server.

A proxy-server provides Internet access to different users at
same time i.e. by sharing a single Internet connection. A good
proxy server also provides for caching of the requests, which helps
to access data from local resources rather fetching the data
from web thus reducing access time and bandwidth. Squid is one
such software which supports proxy, caching of HTTP, ftp,
gopher, etc.. It also supports SSL, access controls, caching of
DNS and maintains a full log of all the requests. Squid is as
well available for Windows-NT from "http://www.logisense.com/">Logi Sense.

The focus of this article is to give basic guidelines of
setting up a proxy server and ways of providing controlled
access to users.
Continua”Setting up a squid proxy server”

Increasing speed of Squirrel mail with Maildir boxes
using IMAP Proxy server.

I love Squirrelmail because it has a bunch of cool plugins
and there are some themes out there. That are really cool.

I found a brazilian website that had a copy of squirrelmail
in brazilian and these guys made squirrelmail look like Outlook
the interface looked nice and you even have a cool looking calendar
that looks like Outlook calendar :)

However, one of the problems i have with Squirrel mail is that
when you have large Maildir boxes it causes a lot of problems
because for everything you do it has to connect to the
imap folder and download email headers all the time.

Continua”Squirrelmail Speed + Imapproxy”

Ruby on Rails on Red Hat

by David Berube

Ruby on Rails is an open source freely available web development framework. It’s been quite popular–it won a Jolt “Web Development Tools” award last year, and some prominent Java developers have publically switched to Ruby on Rails. The buzz surrounding Rails is quite impressive–particularly when you consider that Rails had no Fortune 500 company to market it, unlike .NET or Java.

Continua”How to Install Ruby on Rails on RedHat”