Free Linux Tutorials

There are ways to sync two MySQL tables in a non-GUI method such as mysql triggers or by Maatkit’s MySQL Table Sync, but it’s not that user-friendly.

Of course, if  you want the GUI-type, there’s always the ever dependable phpMyAdmin or the NaviCat program.

On this tutorial, I will be implementing the “TableSyncer” tool, a ruby gem built that was originally detailed on http://code.google.com/p/ruby-roger-useful-functions/wiki/TableSyncer

This was tested on CentOS 5.3 32-bit running in Pentium4@3.0GHz 1G machine.

Here are the step-by-step procedure:

1. Download rubygem by “yum” or by source. This is how I built the rubygem
#wget http://rubyforge.org/frs/download.php/60718/rubygems-1.3.5.tgz
tar zxvf rubygems-1.3.5.tgz

Step by Step Procedure

Step 1. Add 2 LAN cards to the Linux box. You need to have two(2) NICs, one for your private network and one for the public IP address

Step 2. Check if your networks cards are properly detected and installed. You can use the command “dmesg” to verify if it was recognized during the boot-up process

Sample output:
#dmesg |grep eth

e100: eth0: e100_probe: addr 0xfa061000, irq 177, MAC addr 00:10:DC:5E:A8:BF
e100: eth1: e100_probe: addr 0xfa060000, irq 185, MAC addr 00:10:DC:5E:A8:C0
e100: eth0: e100_watchdog: link up, 100Mbps, half-duplex
e100: eth1: e100_watchdog: link up, 100Mbps, full-duplex

The procedure below was tested successfully on CentOS.  The same thing was also implemented on my BSD box and works as well.

Squid is a caching proxy for the Web supporting HTTP, HTTPS, FTP, and more. It reduces bandwidth and improves response times by caching and reusing frequently-requested web pages. Squid has extensive access controls and makes a great server accelerator. It runs on Unix and Windows and is licensed under the GNU GPL.

For those who uses java server pages via Tomcat server on Linux, providing secure transaction on your website thru SSL protocol is a must.  By this of course  we need to install a CA assigned certificate on the server.

The procedure below is a sample installation of  SSL certificate which tested working on my site .

Prerequisites:

Linux (tested on CentOS 4.3 x64 and later)
OpenSSL
JDK 1.5 ( J2SE 1.5.09 at the time of this writing)
Tomcat server (Apache Tomcat 5.5.20 binary version for linux)

SETUP

1.    Linux
It is assumed that CentOS is ready and updated before installation of other packages.

These are the steps on adding additional hard drives on a pre-installed Linux server.

Drives will be detected and can be checked thru the “dmesg” command.

[root@localhost ~]#fdisk /dev/cciss/c0d1

press n to create partition, just use the default settings for it
press w to write exit

3.    Create ext3 filesystem

[root@localhost ~]# mkfs.ext3 /dev/cciss/c0d1p1

4.    Mount that drive to test but first create a directory where to mount it.

[root@localhost ~]#mkdir /data
[root@localhost ~]#mount -t auto /dev/cciss/c0d1p1 /data

Freeradius and MySQL

Software Requirements:

Any Linux distro, kernel 2.4xx-later(tested in CentOS,Fedora Core,RH)
MySQL Server 4.xx-5.xx
GCC compiler
vi editor

1.    Get the latest freeradius source code tarball from www.freeradius.org or get the rpm package using “yum”

2.    Unpack the tarball and install it.
#tar zxvf freeradius-xxx.tar.gz
#cd freeradius
#./configure
#make
#make install

3.    Start with a simple config using the standard text files, this will test if the Freeradius installed is working or not

a.    Edit /etc/raddb/clients.conf to enter the details of the NAS unit.You can enter “localhost” for testing purposes
b.    Edit /etc/raddb/users and create a sample user account

There are lots of operating system virtualization, you have the option to use an open source or a proprietary software depending on your needs,familiarization and most significantly, budget. People have several reasons why they use virtualization, and the most common is for testing purposes wherein they can test different configurations from different OS. Another reason is to security and consolidation, where they can save money and electricity.

Some of the popular open source linux virtualization softwares are OpenVZ, Xen, KVM and VirtualBox. You can also try proprietary softwares such as VMWare and Citrix XenServer, a commercial implementation of Xen.

* Setting up ftp via vsftpd in linux

The VSFTPD (Very Secure FTP Server Deamon) is one of the most commonly used FTP servers under Linux and comes with most Linux distributions.

This article will help you install and configure vsftpd in Linux. (sample OS used is a Red-hat based distribution)

GOALS:

* to create a secure ftp server
* to create an ftp user chrooted or jailed in a certain directory (sample use is an apache directory wherein you can limit users or your developers to just upload to a restricted folder)

Linux.org presented one of the most detailed important events in the history of the Linux operating system development

1983
September    Richard M. Stallman announces the GNU Project, an attempt at creating a completely free operating system.

1984
January    Work begins on the GNU operating system

1985
October    Free Software Foundation established as a non-profit organization to promote the development of Free Software. Sponsors the GNU Project.

1987
January    Computer science professor Andrew Tannenbaum publishes the textbook Operating Systems: Design and Implementation which includes a copy of a teaching version of Unix called Minix.
December    Larry Wall releases version 1.0 of Perl