Category Archives: Operating System

Operating system is computer/device software used to organize how the computer work, mainly as base software that build up and connect all the computer hardware with ability to maintenance and organize how other application work.

Apt.conf Proxy Setting on Ubuntu 11.04

Proxy Setting for Apt is needed for us who work behind proxy. It is needed for ubuntu update, package installation, and ubuntu upgrade. This proxy setting used by apt can be configured with apt.conf and if it’s not configured ubuntu will use or read proxy configuration environtmen. read this post setting proxy bactrack or ubuntu to set proxy environtmen.

On ubuntu 10.04 we can find apt.conf in /etc/apt, but on ubuntu 11.04 i can’t find this file. Reading from some articles i found out that ubuntu 11.04 will still read apt.conf configuration if this file is exist. so i just create file apt.conf in /etc/apt/

1. Create apt.conf
nano /etc/apt/apt.conf

2. Insert lines like this

Acquire::http::proxy “http://proxyserver:port/”;
Acquire::ftp::proxy “ftp://proxyserver:port/”;
Acquire::https::proxy “https://proxyserver:port/”;
Continue reading Apt.conf Proxy Setting on Ubuntu 11.04

Snort Installation on Ubuntu

Snort is free intrusion detection system (ids) for unix, linux, and windows. Snort is very light, means it will not asked your cpu to work to hard. Snort is actually simple to install and to use in it basic installation, it is advanced configuration of course, need more research and practice. Here i will give example of Snort installation on Ubuntu. This guide is for snort 2.9. on Ubuntu 10.04.

Original installation documentation can be found on snort web page.

1. Install dependencies
Snort require these application installed to work well:
sudo apt-get install nmap
sudo apt-get install nbtscan
sudo apt-get install apache2
sudo apt-get install php5
sudo apt-get install php5-mysql
sudo apt-get install php5-gd
sudo apt-get install libpcap0.8-dev
sudo apt-get install libpcre3-dev
sudo apt-get install g++
sudo apt-get install bison
sudo apt-get install flex
sudo apt-get install libpcap-ruby
sudo apt-get install mysql-server
sudo apt-get install libmysqlclient16-dev

2. Update Ubuntu
apt-get update
apt-get upgrade

3. Install Jpgraph and Snortreport
Jpgraph is required to display graph later on our web monitoring
sudo wget
sudo mkdir /var/www/jpgraph
sudo tar zxvf jpgraph-1.27.1.tar.gz
sudo cp -r jpgraph-1.27.1/src /var/www/jpgraph/
Continue reading Snort Installation on Ubuntu

Restart Crontab on FreeBSD and Linux

Cron is one of the most useful utilities in FreeBSD. Cron is application that running in background that checks file /etc/crontab constantly, it is usually used for automatic commands execution. Using cron and this crontab file you can also start any service you want automatically or scheduled.


1. to change crontab or edit crontab file (using ee or vi)
ee /etc/crontab

you will see lines like this

PATH=/etc:/bin:/sbin:/usr/bin:/usr/sbin Continue reading Restart Crontab on FreeBSD and Linux

Pwgen Tutorial Generate Random Password in Linux Unix

Sometimes we need to generate random password to provide rather secure login mecanism for our system. For example if we want to change password randomly for our ftp user. This can be done by using pwgen command. In pwgen man page, i found explanation to use this command. here i will give u the example:

1. basic usage :
pwgen maxleght,
example basic pwgen command and its result:
%pwgen 8

it will generate 8 letter password like ookeokee

2. other usage Continue reading Pwgen Tutorial Generate Random Password in Linux Unix

Windows 8 Taste and Features

windows 8 taste, well this post is actually my friend’s opinion and experience about the newest edition of windows available, windows 8 developer preview. microsoft gives us a chance to experience these features :

1. windows 8 start screen

windows 8 start screen
windows 8 start screen

This is the default start screen replacing the classic desktop. you can still click the classic desktop to switch to the classic layout

2. windows 8 socialite

windows 8 socialite
windows 8 socialite

Socialite is also the name for multiple social network client software in Mac, Microsoft also use this name for its built in facebook client. Continue reading Windows 8 Taste and Features

Play VLC and Chromium Browser on Backtrack 5

Chromium and VLC can’t be run as root. On backtrack 5 with default user root u need to make little modification to these applications.

1. cd /usr/lib/chromium-browser
2. hexedit chromium-browser

u will get

hexedit chromium-browser
hexedit chromium-browser

3. press tab (once) to switch to ascii mode instead of hexa mode. Continue reading Play VLC and Chromium Browser on Backtrack 5

Gnome Terminal Won’t Start on Backtrack / Debian

Maybe it is caused by other program that i installed, suddenly when i wanted to start my gnome terminal in panel my terminal wont start.

To solve this i did these steps,

0. Restart Backtrack dont start X (X-windows) yet.

1. Uninstall latest program/application i installed.
apt-get remove programname

2. Uninstall my gnome-manager.
apt-get remove gnome-manager

3. Reinstall gnome-manager.
apt-get install gnome-manager

4. When finished i start Gnome by command startx and the terminal now works as usual.

Visual Effect on Gnome with Compiz Fusion

visual effect on gnome will make your desktop more beautiful

for installation

aptitude install compiz compizconfig-settings-manager compiz-fusion-plugins-main compiz-gnome compiz-gtk

to enable this feature do :
1. right click on your desktop
2. click change desktop background
3. go to visual effect
4. choose what u prefer

CompizConfig Setting manager

for managing/editing the effect

System > Preferences > CompizConfig Setting manager

Gnome Visual Effect CompizConfig
Gnome Visual Effect CompizConfig

Uninstall Backtrack 5 Dual Boot Win 7

it’s not uninstall actually, hha just simply delete it.

after a month i tried to use backtrack 5, i found out that my disk space allocated for backtrack 5 was nearly empty, 10 GB was too small. So i’d like to add new disk space, but i haven’t found the way to do it. I came up with uncool steps.

1. Remove old backtrack installation
2. Reinstall backtrack with new disk space allocation

to remove backtrack installation, which is dual booted with windows 7, i have to make sure my windows 7 can still work well. after googling, i got the message to do fixmbr to recover windows 7 boot manager. so here are the steps.

A. Fixing windows 7 boot manager
1. prepare your win7 installation disk (dvd/usb), plug it in.
2. start your computer, set the boot priority from bios setting (first boot usb, or cd/dvd room)
3. when windows 7 installation comes up, choose repair
4. choose repair this computer with recovery tool, click next
5. choose command prompt
6. enter this command

[php]bootRec.exe /fixmbr[/php]

7. reboot your computer

B. Remove backtrack
1. now your computer should start the win 7 automatically
2. go to control panel > System and Security > Administrative Tools > Computer Management > choose Disk Management (under storage properties)
3. u will see clearly your computer partitions, delete your backtrack partition by right click > delete Volume
4. after it is deleted you will have new disk space and u can expand your other windows partition.

partition manager
computer management windows 7

that’s all

You don’t have permission to access / on this server.

You don't have permission to access / on this server.
You don't have permission to access / on this server.

when i added new user in my ubuntu hosting and try to access the site, i got the message. i spent some time searching for the problem and solution. my first guess, there is problem with file permission in the home directory. read about unix/linux file permission on my site here.

i use this step to solve the problem.  Continue reading You don’t have permission to access / on this server.