Free Linux Tutorials

I’ve been working with the servers most of the time, and few days ago, i had free time to test ubuntu on one of my laptop, it’s not new but not too old either, it’s dual core MSI VR320 and guess what it’s kinda frustrating to have issues on this laptop upon installing ubuntu 8.04 and 9.04.

with 8.04, wifi (using WPA-PSK at home) is not working and sound is looping
with 9.04, wifi is ok but audio playback is damn too slow.

1. Wonder why you can’t send email from your linux server?

2. Is your mail server or 3rd party email hosting provider requires authentication for your outgoing server to send out emails successfully?

3. Are you using a default sendmail email client on your linux box and wonder why your getting maillog errors such as this:

——-sample sendmail maillog error from my nagios server—————
Oct  2 17:03:54 nms sendmail[25657]: n9293qiw025655: to=<nagios@freelinuxtutorials.com>,

ctladdr=<root@nms.freelinuxtutorials.com> (0/0), dela0928, relay=smtp.freelinuxtutorials.com.

[216.200.145.17], dsn=5.1.1, stat=User unknown
Oct  2 17:03:54 nms sendmail[25657]: n9293qiw025655: n9293siw025657: DSN: User unknown
Oct  2 17:03:54 nms sendmail[25657]: n9293siw025657: to=<root@nms.freelinuxtutorials.com>,

Assuming you already have mysql server installed on your machine, the reason you are
installing phpmyadmin is to ease  your administration of  your MySQL like database creation and deletion, create/alter/drop/view tables and execute any SQL statements, privilege and trigger management, stored procedures, and backup/ maintenance

phyMyAdmin is a tool built in PHP to manage and administer your MySQL servers via your browser.

Requirements:

1.PHP
2.MySQL
3.php-mysql
4.gd/gd-devel
5. Apache

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

I had the chance to work as a systems administrator in an e-commerce company and they have Linux dedicated servers leased/purchase from a hosting provider.
Dedicated servers compared to a shared hosting is you have full control of the box. You can do whatever you want with the box, implement services and of course a full root access with the machine.

In this tutorial, we will be cloning PC desktop machines using an opensource tool called “G4U”.

g4u (”ghosting for unix”) is a NetBSD-based bootfloppy/CD-ROM that allows easy cloning of PC harddisks to deploy a common setup on a number of PCs using FTP. The floppy/CD offers two functions. more details on –>   http://www.feyrer.de/g4u/

Here’s one trick to do that:
Step 1. Install  FreeTDS

FreeTDS Website: http://www.freetds.org/ choose FreeTDS source distribution

Compile parameter: –prefix=/usr/local/freetds –enable-msdblib

Then, copy /etc/ld.so.conf, to /usr/local/freetds/lib; and then run ldconfig

Step 2. Change /usr/local/freetds/etc/freetds.conf

[sql2k]

host = your.mssql.server.ip
port = 1433
client charset = cp950
tds version = 8.0

b. tds version: 4.2 (for MS SQL Server 6.x); 7.0 (for 7.x); 8.0 (for 2000)

Step 3. Test FreeTDS connect to MS SQL Server

#cd /usr/local/freetds/bin
#./tsql -S sql2k -U sa
1> use mydatabase
2> select * from mytable
3> go

Want to test your Asterisk PBX system if it can sustain load and large traffic? Then you can use this tool.
Sipp is a performance testing tool for the SIP protocol. Its main features are basic SIPStone scenarios, TCP/UDP transport, customizable (xml based) scenarios, dynamic adjustement of call-rate and a comprehensive set of real-time statistics.
Sipp can be used to test real SIP equipments and very useful to emulate thousands of user agents calling your SIP system.

Installation:

1.    Download the stable version of Sipp ( sipp-xxx.tar.gz)
2.    Uncompress the tarball file
#tar zxvf sipp-xxx.tar.gz
#cd sipp
#make

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

1.compile cronolog (http://cronolog.org) and install it on /usr/local/sbin
2. backup orig /usr/local/apache-tomcat-5.5.20/bin/catalina.sh  on /root
3. edit lines on catalina.sh from
org.apache.catalina.startup.Bootstrap “$@” start \
>> “$CATALINA_BASE”/logs/catalina.out 2>&1 &

to

org.apache.catalina.startup.Bootstrap “$@” start 2>&1 \
| /usr/local/sbin/cronolog “$CATALINA_BASE”/logs/catalina.out.%Y-%m-%d >> /dev/null &

4. Removed the line
touch “$CATALINA_BASE”/logs/catalina.out

5. Restart web service
#/usr/local/tomcat/bin/shutdown.sh
# service httpd stop
# /usr/local/tomcat/bin/startup.sh
#service httpd start

TESTING

1.    Check tomcat logs to see generated Catalina.out per day
# ls -la /usr/local/tomcat/logs

-rw-r–r–   1 root root      65607 Nov  6 14:55 catalina.out.2007-11-06

2.    browse ww2.freelinuxtutorials.com and login using test account to see if tomcat is working