Free Linux Tutorials

Relaying to Gmail via smtp.gmail.com can be accomplished by configuring your Postfix with SASL authentication and TLS encryption.

The common errors you will encounter if sending from your postfix mail server failing to gmail.com domain but works in other domains are:

@/var/log/maillog
-Must issue a STARTTLS command first
-certificate verification failed for gmail.com:unable to get local issuer certificate
-Authentication Required. Learn more at 530 5.5.1 http://mail.google.com/support/bin/answer.py?

How to fix?

Assuming you already installed Postfix and everything works fine except sending to gmail smtps, here are the steps to follow:

1. Configure Postfix main configuration

If you have multiple virtual hosts in your server and you specified different log files for each, it is more organized and easy to locate, but the downside is Linux has so called file descriptors or the number of files that it can be handle. Basically , it can be increased but I think it’s not really recommended just for the sake of it.
Making your apache logs more organized can be done by many ways, one way is via piped logging and use rotatelogs. And based on my tips before named Automatic unlimited subdomains via Apache mod_rewrite, one issue is the log files. But there’s one method to solve this, and this is by splitting up your log files.

Wondering how blogger website gives you a subdomain from the blogspot.com domain based on  your username of your choice? Well, the concept for this tutorial is somewhat related with it on setting up unlimited subdomains. I’m not sure how do they do it because it could be done by any script, hardcoded or not, thru static or dynamic way via database, many possibilities, and one possible way is thru URL rewriting via Apache’s mod_rewrite.

Requirements of this setup:

a. Apache 2.x or later
mod_rewrite module should be enable.  To check if it’s enabled you should see this line on your httpd.conf

One of the most important procedure in setting up master-slave replication on Mysql database successfully is to have a consistent dump or backup of database(s) from the master server by locking all tables during mysqldump so write access is not possible.

master log file and log position will be taken from the master and configure it on the slave server. But it’s not always good times. There are some bad times too. And one of it is sudden stop of your slave and no longer synching with the master database.

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/