July 2008 | Linux Blog

Create your own web based personal desktop - eyeOS

eyeOS is an Open Source Platform designed to hold a wide variety of Web Applications over it. eyeOS was thought as a new definition of Operating System, where everything inside it can be accessed from everywhere in a Network. All you need to do is to login into your eyeOS server with a normal Internet Browser, and access your personal desktop, with your applications, documents, music, movies... just like you left it last time.

With the base system you can find a full suite of applications bundled, some for private use, like the file manager, a word processor, a music player, calendar, notepad or contacts manager. There are also some groupware applications, such as a group manager, a file sharing application, a group board and many more.

The idea behind eyeOS is not to have an Operating System inside an Operating System, or a browser inside a browser. eyeOS is another step in the digital life era:

Being able to work from everywhere, despite of using a full featured modern computer, a mobile gadget or a completely obsolete pc.

Sharing resources easily between different work centers of a same company, or working from different places and countries in the same projects.

Enjoying always the same applications with the same open formats, and forgetting the usual compatibility problems between Office suites or traditional operating systems.

Being able to continue working if you have to leave your local computer or it just crashes, without loosing data or time in solving its problems: Just log in to your eyeOS from another place and continue working.

Check the screen shot below of my personal eyeOS running under Firefox (OpenSuse 11)

To install eyeOS, please follow these steps:
1. Check the Server and Client Requirements.
2. Download eyeOS in your preferred format (tar.gz or zip).
3. Extract its contents to a local directory.
4. Upload the directory within all of its content to your web server.
5. Give full read-write permissions to folder where you have put them and the files itselfs.
6. Now launch the file install.php in your browser and follow the given instructions.
7. If you want to activate the Office Support, please follow the instructions at this wiki page.
8. Now enjoy eyeOS!

Block root access to SSH service

SSH (Secure Shell) is a protocol for creating a secure connection between two computers.The secure SSH connection provides authentication and encryption. SSH also provides compression and is most common way for users and root to get connect to the server (Linux), the main reson behind blocking the root user is to allow the admin to login into the box with the default normal user and do the the administrator task using sudo, no direct root login.

1. vi /etc/ssh/sshd_config
3. Locate the parameter -- PermitRootLogin yes
4. Change this to PermitRootLogin no
5. Save and exit
6. Restart your sshd by type /etc/init.d/sshd restart

Free SSH Clients

SSH Client	Operating Systems Supported
OpenSSH	AIX, HP-UX, Irix, Linux, NeXT, SCO, SNI/Reliant Unix, Solaris, Digital Unix/Tru64/OSF, Mac OS X, and Cygwin
FreSSH	NetBSD, FreeBSD, Linux
lsh	GNU/Linux on Sparc, Intel, PPC and Alpha, FreeBSD, Solaris and IRIX
OpenSSH for Windows	Windows
PuTTY	Win32 and Unix
MSSH	Windows
WinSCP	Windows (SCP and SFTP, no SSH)
Fugu	Macintosh
MacSSH	Macintosh
Cyberduck	Macintosh (SFTP only)
pssh	Palm OS
TuSSH	Palm OS

Scientific version of Ubuntu - Poseidon Linux

Poseidon Linux was designed as a friendly and complete desktop, based on open source software and aimed at the Brazilian/International scientific community. This operating system is based on Ubuntu and inspired by Quantian Linux. It offers several specific tools in the areas of GIS, 3D Visualization, Mathematics, Statistics and several otherfields of research. It also has all the software expected in a modern desktop such as an office suite - with spell checker, web browsers, e-mail readers, instant messaging, to cite but a few.

It includes a large number of scientific applications, covering areas such as:

GIS and Geostatistics

Visualization 2D/3D/4D

Mathematics

Statistics

Physics

Chemistry

CAD / Engineering

Computer Graphics

Image Editing and Vectorial Drawing

Numeric modelling / Simulation

Scientific graphs

Scientific Authoring

Database

Programming languages

Poseidon Linux 3.0 also offers all software needed to make it a complete workstation - office suite, web browser, e-mail readers, instant messaging, among others.

To download Poseidon Linux 3.0 now, please click here

How To install/upgrade KDE 4.1 on OpenSuse 11.0

On 29th July 2008, The KDE Community released KDE 4.1.0. This release is the second feature release of the KDE 4 series, sporting new applications and newly developed features on top of the Pillars of KDE4.

KDE 4.1 is the first KDE4 release to contain the Personal Information Management suite KDE-PIM with its E-Mail client KMail, the planner KOrganizer, Akregator, the RSS feed reader, KNode, the newsgroup reader and many more components integrated into the Kontact shell. Furthermore, the new desktop shell Plasma, introduced in KDE 4.0, has matured to the point where it can replace the KDE 3 shell for most casual users. Like with previous release much time has been devoted to improving the framework and underlying libraries on which KDE is built.

Upgrade your OpenSuse 11 with KDE 4.1

Regular KDE 4 Packages and an openSUSE-based KDE Four Live CD have been available throughout the whole cycle, and final versions of them are also available now. On openSUSE 11.0 you can use 1-click-install to get the KDE 4.1 desktop environment (for openSUSE 10.3 follow link below):

Here

Or you can choose to install a more basic KDE 4 desktop. Developers can also optionally install the KDE 4 build dependencies: all the packages you need to have installed for compiling KDE 4.x from source (experts only).

UNIX System V Signals

Symbol     Number   Action       Meaning


SIGHUP     1        exit         Hangs up.
SIGINT     2        exit         Interrupts.
SIGQUIT    3        core dump    Quits.
SIGILL     4        core dump    Illegal instruction.
SIGTRAP    5        core dump    Trace trap.
SIGIOT     6        core dump    IOT instruction.
SIGEMT     7        core dump    MT instruction.
SIGFPE     8        core dump    Floating point exception.
SIGKILL    9        exit         Kills (cannot be caught or ignored).
SIGBUS     10       core dump    Bus error.
SIGSEGV    11       core dump    Segmentation violation.
SIGSYS     12       core dump    Bad argument to system call.
SIGPIPE    13       exit         Writes on a pipe with no one to read it.
SIGALRM    14       exit         Alarm clock.
SIGTERM    15       exit         Software termination signal.

Linux Filesystem Testing Tools

Filesystems:

Bonnie	Bonnie++ is test suite, which performs several hard drive/ filesystem tests.
dbench	Filesystem benchmark that generates good filesystem load
fs_inode	Part of the LTP: This test creates several subdirectories and files off of two parent directories and removes directories and files as part of the test.
fs_maim	Part of the LTP: a set of scripts to test and stress filesystem and storage management utilities
IOZone	Filesystem benchmark tool (read, write, re-read, re-write, read backwards, read strided, fread, fwrite, random read, pread, aio_read, aio_write)
lftest	Part of the LTP:lftest is a tool/test designed to create large files and lseek from the beginning of the file to the end of the file after each block write. This test verifies large file support and can be used to generate large files for other filesystem tests.	Files up to 2Tb have been created using this tool. This test is VERY picky about glibc version.
LTP	The Linux Test Project is a collection of tools for testing the Linux kernel and related features.
PostMark	Filesystem benchmark that simulates load generated by enterprise applications such as email, news and web-based commerce.
stress	puts the system under a specified amount of load
mongo	set of the programs to test linux filesystems for performance and functionality
fsx	File system exerciser from Apple.	The test is most effective if you let it run for a minute or two, so that it overlaps the periodic sync that most Unix systems do.
xdd	Storage I/O Performance Characterization tool that runs on most UNIX-like systems and Windows.	Has been around since 1992 and is in use at various government labs.

How to Force fsck (Filesystem check) on next boot

If you want to force fsck on the next boot, just create a file called /forcefsck . If this file is present, then during next boot - the fsck is forced.

# touch /forcefsck

Now reboot the machine and when it comes up, fsck will be forced.

# reboot

How To get Harware information in OpenSuse 11

Use YaST, if you want to know more about your hardware or if you need to find out details like vendor and model of a certain hardware to be able to properly configure it. Open yast2 by typing the command "yast2" (you need to be root)

1.In YaST, click Hardware+Hardware Information. Hardware probings starts immediately and it will take some time until you see the hardware information tree in a separate window. Something similar to this ...

2.In the hardware information tree recursively click on the plus icons to expand the information about a specific device.

3.Click Close to leave the hardware information overview.

Copying Files between Linux and Windows Computers with SSH

To transfer files from Linux to Windows using SSH, choose one of the following applications:

PuTTY

PuTTY is a suite of different command line tools for working with an SSH daemon. Download it from http://www.chiark.greenend.org.uk/~sgtatham/putty.html.

WinSCP

WinSCP is very similar to PuTTY, but includes a graphical user interface. Choose from an Explorer or Norton Commander style. Download it from http://winscp.net.

To copy a file from Windows to Linux with PuTTY, proceed as follows (on the Windows machine):

1.Start PSCP.
2.Enter the hostname of your SSH server.
3.Enter your login and password to the SSH server.

To connect from Windows to Linux with WinSCP, proceed as follows (on the Windows machine):

1.Start WinSCP.
2.Enter the hostname of the SSH server and username.
3.Click Login and acknowledge the following warning.
4.Drag and drop any files or directories from or to your WinSCP window.

BSD - True Friend of Linus Torvalds

Linus Torvalds is often famous for his outrageous statements. One of those famous statements was made yesterday, that will probably go down in history as one of the funniest quotes ever made by Linus.

You can read his comment in context with the rest of his post here.

I just want to say this in record that I have nothing against BSD, but this is one of those comments that needs to be mentioned, regardless of your feelings towards the subject.

Here are some other outrageous comments Linus has made in the past:

“My name is Linus, and I am your God.”
Linus’ law (nr 76 of 271):
“Don’t claim to have a config option, if you don’t actually have the UI
to change it” (source)
“I have an ego the size of a small planet”
“An infinite number of monkeys typing into GNU emacs would never make a good program.”
“Really, I’m not out to destroy Microsoft. That will just be a completely unintentional side effect.”

His quotes are popular enough to have their own wikiqoute section.
So what do you guys think of the new BSD logo? (fanboys can relax, it’s just a harmless phun)

Note: If anyone has any objection to the picture above, please let me know, I will remove it.

Source : http://www.linuxhaxor.net/2008/07/16/new-logo-for-bsd/

DNS protocol monitoring and spoofing program

Zodiac is a DNS protocol analyzation and exploitation program. It is a robust tool to explore the DNS protocol. Internally it contains advanced DNS routines for DNS packet construction and disassembling and is the optimal tool if you just want to try something out without undergoing the hassle to rewrite DNS packet routines or packet filtering.

Zodiac has been developed and tested on the Linux 2.2.x platform. It should work on all platforms that do have POSIX Threads, the terminal library ncurses and the libpcap packet capture library installed. To run zodiac you need root access for obvious reasons

Features

sniffing on all kinds of configured devices (Ethernet, PPP, …)
capturing and decoding nearly all types of DNS packets, including packet decompression
ncurses driven text based frontend with interactive commandline and multiple windows
threaded design allow more flexibility when adding your own features
clean code, commented and tested just fine, ready for you to extend
internal DNS packet filtering allows installation of pseudo DNS filters you can “select()” on a large set of DNS packet construction primitives
DNS name server versioning using BIND version requests
DNS local spoofing, answering DNS queries on your LAN before the remote NS
DNS jizz spoofing, exploiting a weakness within old BIND versions
DNS ID spoofing, exploiting a weakness within the DNS protocol itself

Download: zodiac-0.4.9.tar.gz

Bandwidth Shaping using wondershaper

Traffic shaping on Linux system used to require knowledge of lot of things like iptables, qdiscs & networking protocols. Things have changed and now there are couple of tools which handle all of this complexity without requiring much knowledge. And one of them is wondershaper.

First install wondershper before using any of the command mentioned below also, you need to be root.

1) Use ifconfig to determine which of your networkcards is connected to internet.

# ifconfig

2) Time to shape the bandwidth--

# wondershaper

Where interface name is your network interface name like eth0 or eth1 or wifi0 and down speed , up speed are specified in kilo bits per second.

So sample command will look like

# wondershaper eth0 128 64

3) To disable wondershaper from controlling particular interface use following command.

# wondershaper clear eth0

4) To make these changes permanent add following lines to network file

up /sbin/wondershaper
down /sbin/wondershaper clear

How to Apply GNU General Public License to Your Programs

If you develop a new program, and you want it to be of the greatest possible use to the public, the best way to achieve this is to make it free software which everyone can redistribute and change under these terms.

To do so, attach the following notices to the program. It is safest to attach them to the start of each source file to most effectively convey the exclusion of warranty; and each file should have at least the “copyright” line and a pointer to where the full notice is found.

one line to give the program’s name and an idea of what it does. Copyright (C) yyyy name of author

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

Also add information on how to contact you by electronic and paper mail.

If the program is interactive, make it output a short notice like this when it starts in an interactive mode:

Gnomovision version 69, Copyright (C) year name of author Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w’. This is free software, and you are welcome to redistribute it under certain conditions; type `show c’ for details.

The hypothetical commands `show w’ and `show c’ should show the appropriate parts of the General Public License. Of course, the commands you use may be called something other than `show w’ and `show c’; they could even be mouse-clicks or menu items--whatever suits your program.

You should also get your employer (if you work as a programmer) or your school, if any, to sign a “copyright disclaimer” for the program, if necessary.

Please Note -- This General Public License does not permit incorporating your program into proprietary programs. If your program is a subroutine library, you may consider it more useful to permit linking proprietary applications with the library. If this is what you want to do, use the GNU Lesser General Public License instead of this License.

List of OpenSource Performance Testing Tools

Apache JMeter
Description:
Apache JMeter is a 100% pure Java desktop application designed to load test functional behavior and measure performance. It was originally designed for testing Web Applications but has since expanded to other test functions. Apache JMeter may be used to test performance both on static and dynamic resources (files, Servlets, Perl scripts, Java Objects, Data Bases and Queries, FTP Servers and more). It can be used to simulate a heavy load on a server, network or object to test its strength or to analyze overall performance under different load types. You can use it to make a graphical analysis of performance or to test your server/script/object behavior under heavy concurrent load.
Requirement:
Solaris, Linux, Windows (98, NT, 2000). JDK1.4 (or higher).

benerator
Description:
benerator is a framework for creating realistic and valid high-volume test data, used for (unit/integration/load) testing and showcase setup. Metadata constraints are imported from systems and/or configuration files. Data can be imported from and exported to files and systems, anonymized or generated from scratch. Domain packages provide reusable generators for creating domain-specific data as names and addresses internationalizable in language and region. It is strongly customizable with plugins and configuration options.
Requirement:
Platform Independent

CLIF is a Load Injection Framework
Description:
CLIF is a modular and flexible distributed load testing platform. It may address any target system that is reachable from a Java program (HTTP, DNS, TCP/IP...) CLIF provides 3 user interfaces (Swing or Eclipse GUI, command line) to deploy, control and monitor a set of distributed load injectors and resource consumption probes (CPU, memory...) An Eclipse wizard helps programming support for new protocols. Load scenarios are defined through XML-editing, using a GUI, or using a capture tool. The scenario execution engine allows the execution of up to millions of virtual users per load injector.
Requirement:
Java 1.5 or greater, with enhanced support for Linux, Windows XP, MacOSX/PPC

curl-loader
Description:
A C-written web application testing and load generating tool. The goal of the project is to provide a powerful open-source alternative to Spirent Avalanche and IXIA IxLoad. The loader uses real HTTP, FTP and TLS/SSL protocol stacks, simulating tens of thousand and hundred users/clients each with own IP-address. The tool supports user authentication, login and a range of statistics.
Requirement:
linux

Database Opensource Test Suite
Description:
The Database Opensource Test Suite (DOTS) is a set of test cases designed for the purpose of stress-testing database server systems in order to measure database server performance and reliability.
Requirement:
Linux, POSIX

DBMonster
Description:
DBMonster is an application to generate random data for testing SQL database driven applications under heavy load.
Requirement:
OS Independent

Deluge
Description:
An open-source web site stress test tool. Simulates multiple user types and counts. Includes proxy server for recording playback scripts, and log evaluator for generating result statistics. Note: this tool is no longer under active development although it is still available on Sourceforge.
Requirement:
OS independent

Dieseltest
Description:
Contains the high-end features common to packages costing $50,000 or more. Dieseltest is a Windows application that simulates hundreds or thousands of users hitting a website. To run a load test, you first create a test script using our script editor. The script contains all of the requests that a real-world user would make of a website. You then load the script and run the test. The system will show you real-time results while the script is running, and produce a report analyzing the results at the conclusion.
Requirement:
Windows

Faban
Description:
Faban is a facility for developing and running benchmarks, developed by Sun. It has two major components, the Faban harness and the Faban driver framework. The Faban harness is a harness to automate running of server benchmarks as well as a container to host benchmarks allowing new benchmarks to be deployed in a rapid manner. Faban provides a web interface to launch & queue runs, and extensive functionality to view, compare and graph run outputs.
Requirement:
OS independent; JVM 1.5 or later.

FunkLoad
Description:
FunkLoad is a functional and load web tester, written in Python, whose main use cases are functional and regression testing of web projects, performance testing by loading the web application and monitoring your servers, load testing to expose bugs that do not surface in cursory testing, and stress testing to overwhelm the web application resources and test the application recoverability, and writing web agents by scripting any web repetitive task, like checking if a site is alive.
Requirement:
OS independent - except for the monitoring which is Linux specific.

Grinder
Description:
The Grinder is a Java load-testing framework making it easy to orchestrate the activities of a test script in many processes across many machines, using a graphical console application.
Requirement:
OS Independent

Hammerhead 2 - Web Testing Tool
Description:
Hammerhead 2 is a stress testing tool designed to test out your web server and web site. It can initiate multiple connections from IP aliases and simulated numerous (256+) users at any given time. The rate at which Hammerhead 2 attempts to pound your site is fully configurable, there are numerous other options for trying to create problems with a web site (so you can fix them).
Requirement:
Hammerhead has been used with Linux, Solaris and FreeBSD.

Hammerora
Description:
Hammerora is a load generation tool for the Oracle Database and Web Applications. Hammerora includes pre-built schema creation and load tests based on the industry standard TPC-C and TPC-H benchmarks to deploy against the Oracle database with multiple users. Hammerora also converts and replays Oracle trace files and enables Web-tier testing to build bespoke load tests for your entire Oracle application environment.
Requirement:
Platform Independent (Binaries for Linux and Windows)

httperf
Description:
Httperf is a tool for measuring web server performance. It provides a flexible facility for generating various HTTP workloads and for measuring server performance. The focus is not on implementing one particular benchmark but on providing a robust, high-performance tool that facilitates the construction of both micro and macro level benchmarks. The three distinguishing characteristics of httperf are its robustness, which includes the ability to generate and sustain server overload, support for the HTTP/1.1 and SSL protocols, and its extensibility.
Requirement:
linux (Debian package available), HP-UX, perhaps other Unix

http_load
Description:
http_load runs multiple HTTP fetches in parallel, to test the throughput of a Web server. However, unlike most such test clients, it runs in a single process, to avoid bogging the client machine down. It can also be configured to do HTTPS fetches.
Requirement:
tbc

JChav
Description:
JChav is a way to see the change in performance of your web application over time, by running a benchmark test for each build you produce. JChav reads all the JMeter logs from each of your runs (one per build), and produces a set of charts for each test in each run.
Requirement:
JMeter

JCrawler
Description:
Stress-Testing Tool for web-applications. It comes with the crawling/exploratory feature. You can give JCrawler a set of starting URLs and it will begin crawling from that point onwards, going through any URLs it can find on its way and generating load on the web application. The load parameters (hits/sec) are configurable.
Requirement:
OS Independent

Lobo, Continuous Tuning
Description:
Lobo is a tool for performance testing and monitoring that allows you to monitor the evolution of performance along the time-line of the project. It was specially designed to be used in agile-iterative and evolutionary approaches.
Requirement:
Java

NTime
Description:
The NTime tool is very similar to NUnit tool to perform repeatable tasks that help managers, architects, developers and testers to test an application against its performance.
Requirement:
Windows 98 or above, .Net framework 1.1 or 2.0

OpenSTA
Description:
A distributed software testing architecture based on CORBA. Using OpenSTA (Open System Testing Architecture) a user can generate realistic heavy loads simulating the activity of hundreds to thousands of virtual users. OpenSTA graphs both virtual user response times and resource utilization information from all Web Servers, Application Servers, Database Servers and Operating Platforms under test, so that precise performance measurements can be gathered during load tests and analysis on these measurements can be performed.
Requirement:
Windows 2000, NT4 and XP

OpenWebLoad
Description:
OpenWebLoad is a tool for load testing web applications. It aims to be easy to use and providing near real-time performance measurements of the application under test.
Requirement:
Linux, Windows

p-unit
Description:
An open source framework for unit test and performance benchmark, which was initiated by Andrew Zhang, under GPL license. p-unit supports to run the same tests with single thread or multi-threads, tracks memory and time consumption, and generates the result in the form of plain text, image or pdf file.
Requirement:
OS Independent

PandoraFMS
Description:
Pandora FMS is a monitoring Open Source software. It watches your systems and applications, and allows you to know the status of any element of those systems. Pandora FMS could detect a network interface down, a defacement in your website, a memory leak in one of your server application, or the movement of any value of the NASDAQ new technology market. If you want, Pandora FMS could send out SMS message when your systems fails... or when Google's value drop below US$ 500.
Requirement:
32-bit MS Windows (NT/2000/XP), All POSIX (Linux/BSD/UNIX-like OSes), Solaris, HP-UX, IBM AIX

Pylot
Description:
Pylot is a free open source tool for testing performance and scalability of web services. It runs HTTP load tests, which are useful for capacity planning, benchmarking, analysis, and system tuning. Pylot generates concurrent load (HTTP Requests), verifies server responses, and produces reports with metrics. Tests suites are executed and monitored from a GUI.
Requirement:
Python 2.5+. required.Tested on Windows XP, Vista, Cygwin, Ubuntu, MacOS

Seagull
Description:
Seagull is a multi-protocol traffic generator test tool. Primary aimed at IMS protocols, Seagull is a powerful traffic generator for functional, load, endurance, stress and performance tests for almost any kind of protocol. Currently supports Diameter, XCAP over HTTP, TCAP (GSM Camel, MAP, Win) protocols.
Requirement:
Linux/Unix/Win32-Cygwin

Siege
Description:
SIEGE is an http regression testing and benchmarking utility. It was designed to let web developers measure the performance of their code under duress, to see how it will stand up to load on the internet. It lets the user hit a webserver with a configurable number of concurrent simulated users. Those users place the webserver "under siege." SCOUT surveys a webserver and prepares the urls.txt file for a siege. In order to perform regression testing, siege loads URLs from a file and runs through them sequentially or randomly. Scout makes the process of populating that file easier. You should send out the scout, before you lay siege.
Requirement:
GNU/Linux, AIX, BSD, HP-UX and Solaris.

Sipp
Description:
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. It can also generate media (RTP) traffic for audio and video calls.
Requirement:
Linux/Unix/Win32-Cygwin

SLAMD
Description:
SLAMD Distributed Load Generation Engine is a Java-based application designed for stress testing and performance analysis of network-based applications.
Requirement:
Any system with Java 1.4 or higher

Soap-Stone
Description:
Network benchmark application which can put your network under load and conduct automatic benchmark and recording activities.
Requirement:
OS Independent

stress_driver
Description:
General-purpose stress test tool.
Requirement:
Windows NT/2000, Linux

TestMaker
Description:
TestMaker from PushToTest.com delivers a rich environment for building and running intelligent test agents that test Web-enabled applications for scalability, functionality, and performance. It comes with a friendly graphical user environment, an object-oriented scripting language (Jython) to build intelligent test agents, an extensible library of protocol handlers (HTTP, HTTPS, SOAP, XML-RPC, SMTP, POP3, IMAP), a new agent wizard featuring an Agent Recorder to write scripts for you, a library of fully-functional sample test agents, and shell scripts to run test agents from the command line and from unit test utilities.
Requirement:
Java 1.4 or higher virtual machine on Windows, Linux, Solaris, and Macintosh.

TPTEST
Description:
The purpose with TPTEST is to allow users to measure the speed of their Internet connection in a simple way. TPTEST measures the throughput speed to and from various reference servers on the Internet. The use of TPTEST may help increase the consumer/end user knowledge of how Internet services work.
Requirement:
MacOS/Carbon and Win32

Tsung
Description:
Tsung is a distributed load testing tool. It is protocol-independent and can currently be used to stress HTTP, SOAP and Jabber servers (SSL is supported). It simulates complex user's behaviour using an XML description file, reports many measurements in real time (including response times, CPU and memory usage from servers, customized transactions, etc.). HTML reports (with graphics) can be generated during the load. For HTTP, it supports 1.0 and 1.1, has a proxy mode to record sessions, supports GET and POST methods, Cookies, and Basic WWW-authentication. It has already been used to simulate thousands of virtual users.
Requirement:
Tested on Linux, but should work on MacOSX and Windows.

Valgrind
Description:
Valgrind is an award-winning suite of tools for debugging and profiling Linux programs. With the tools that come with Valgrind, you can automatically detect many memory management and threading bugs, avoiding hours of frustrating bug-hunting, making your programs more stable. You can also perform detailed profiling, to speed up and reduce memory use of your programs.
Requirement:
Linux

Web Application Load Simulator
Description:
LoadSim is a web application load simulator. It allows you to create simulations and have those simulations run against your webserver.
Requirement:
JDK 1.3 or above

Web Polygraph
Description:
Benchmarking tool for caching proxies, origin server accelerators, L4/7 switches, content filters, and other Web intermediaries.
Requirement:
C++ compiler

WebLOAD
Description:
WebLOAD Open Source is a fully functional, commercial-grade performance testing product based on WebLOAD, Radview's flagship product that is already deployed at 1,600 sites. Available for free download and use, WebLOAD is a commercial-grade open source project with more than 250 engineering years of product development. Companies that require commercial support, additional productivity features and compatibility with third-party protocols have the option of purchasing WebLOAD Professional directly from RadView.
Requirement:
Windows NT/2000/XP

Linux Directory Structure - Explained

The following list provides more detailed information and gives some examples which files and subdirectories can be found in the directories:

/bin

Contains the basic shell commands that may be used both by root and by other users. These commands include ls, mkdir, cp, mv, rm, and rmdir. /bin also contains Bash, the default shell.

/boot

Contains data required for booting, such as the boot loader, the kernel, and other data that is used before the kernel begins executing user mode programs.

/dev

Holds device files that represent hardware components.

/etc

Contains local configuration files that control the operation of programs like the X Window System. The /etc/init.d subdirectory contains scripts that are executed during the boot process.

/home/username

Holds the private data of every user who has an account on the system. The files located here can only be modified by their owner or by the system administrator.

/lib

Contains essential shared libraries needed to boot the system and to run the commands in the root file system. The Windows equivalent for shared libraries are DLL files.

/media

Contains mount points for removable media, such as CD-ROMs, USB sticks, and digital cameras (if they use USB). /media generally holds any type of drive except the hard drive of your system. As soon as your removable medium has been inserted or connected to the system and has been mounted, you can access it from here.

/mnt

This directory provides a mount point for a temporarily mounted file system. root may mount file systems here.

/opt

Reserved for the installation of additional software. Optional software and larger add-on program packages can be found there.

/root

Home directory for the root user. Personal data of root is located here.

/sbin

As the s indicates, this directory holds utilities for the superuser. /sbin contains binaries essential for booting, restoring, and recovering the system in addition to the binaries in /bin.

/srv

Holds data for services provided by the system, such as FTP and HTTP.

/tmp

This directory is used by programs that require temporary storage of files.

/usr

/usr has nothing to do with users, but is the acronym for UNIX system resources. The data in /usr is static, read-only data that can be shared among various hosts compliant to the Filesystem Hierarchy Standard (FHS). This directory contains all application programs and establishes a secondary hierarchy in the file system. KDE4 and GNOME are also located here. /usr holds a number of subdirectories, such as /usr/bin, /usr/sbin, /usr/local, and /usr/share/doc.

/usr/bin

Contains generally accessible programs.

/usr/sbin

Contains programs reserved for the system administrator, such as repair functions.

/usr/local

In this directory, the system administrator can install local, distribution-independent extensions.

/usr/share/doc

Holds various documentation files and the release notes for your system. In the manual subdirectory, find an online version of this manual. If more than one language is installed, this directory may contain versions of the manuals for different languages.

Under packages, find the documentation included in the software packages installed on your system. For every package, a subdirectory /usr/share/doc/packages/packagename is created that often holds README files for the package and sometimes examples, configuration files, or additional scripts.

/var

Whereas /usr holds static, read-only data, /var is for data which is written during system operation and thus is variable data, such as log files or spooling data. For example, the log files of your system are in /var/log/messages (only accessible for root).

Linus Torvalds uses Fedora 9

Linus Torvalds, an acknowledged godfather of the open-source movement, was just 21 when he changed the world by writing Linux

Today, 17 years later, Linux powers everything from supercomputers to mobile phones. In fact ask yourself this: if Linux didn't exist, would Google, Facebook, PHP, Apache, or MySQL?

Linus is the son of the journalists Anna and Nils Torvalds, He was attracted to computers from an early age and attended the University of Helsinki from 1988 to study Computer Science. In 1991, he purchased a PC. As the computers at the university were Unix-based, he bought a copy of Andrew Tanenbaum’s MINIX operating system. He was dissatisfied with it, and set about writing his own Unix clone from scratch, unaware of the enormity of the task.. After four months work, in his bedroom in his mother’s apartment, he announced, in the MINIX newsgroup comp.os.minix …

“I'm doing a (free) operating system (just a hobby, won't be big and professional like gnu) for 386 (486) AT clones. This has been brewing since april, and is starting to get ready.”

Torvalds called it Linux (short for Linus' MINIX). He took a break from his studies to work full-time on the project. By the end of October he was able to announce, ‘It has finally reached the stage where it's even usable’, and released Linux under the GPL (GNU General Public License). It soon became the focus of the largest collaborative ‘open source’ project ever undertaken, including geek superstars Fred van Kempen and Alan Cox.. Linus led the development work, not just by his technical brilliance, but by his engaging and genial personality.

'Which Linux distro do you use? '

Linus: 'I've used different distributions over the years. Right now I happen to use Fedora 9 on most of the computers I have, which really boils down to the fact that Fedora had fairly good support for PowerPC back when I used that, so I grew used to it. But I actually don't care too much about the distribution, as long as it makes it easy to install and keep reasonably up-to-date. I care about the kernel and a few programs, and the set of programs I really care about is actually fairly small.

And when it comes to distributions, ease of installation has actually been one of my main issues - I'm a technical person, but I have a very specific area of interest, and I don't want to fight the rest. So the only distributions I have actively avoided are the ones that are known to be "overly technical" - like the ones that encourage you to compile your own programs etc.

Yeah, I can do it, but it kind of defeats the whole point of a distribution for me. So I like the ones that have a name of being easy to use. I've never used plain Debian, for example, but I like Ubuntu. And before Debian people attack me - yeah, I know, I know, it's supposedly much simpler and easier to install these days. But it certainly didn't use to be, so I never had any reason to go for it. '

More here

How to find the linux operating system and kernel version

To find the linux operating system and kernel version:

# cat /proc/version

Example
cat /proc/version

How to list the partition table information in linux

To list the partition table for a specified device:

# fdisk -l /dev/sda

If no devices are given, those mentioned in /proc/partitions (if that exists) are used:

# fdisk -l

How To use zypper in OpenSuse

Installing and Removing Software with Zypper

To install a package from registered repositories, use

zypper install package_name

To remove an installed package, use

zypper remove package_name

By default, zypper asks for confirmation before installing or removing a selected package. Override this behavior using the --non-interactive option.

Updating Software with Zypper

There are two different ways to update software using zypper. To integrate all officially released patches into your system, just run the

zypper update

command. In this case, all patches that are available in your repositories are checked for relevance, and installed if necessary.

If a repository just has new packages, but does not provide patches, zypper update does not show any effect. To update all of these packages, you must specify to install updates of the type package:

zypper update -t package

To update individual packages, simply use the installation command:

zypper install package_name

A list of all new packages available can be obtained with the command

zypper list-updates -t package

Managing Repositories

All installation or update commands of zypper rely on a list of repositories known to zypper. To list all repositories known to the system, use the command

zypper repos

If you want to remove a repository from the list, use the command zypper renamerepo together with the alias of the repository you want to delete. To remove the Main Repository (Non-OSS) from the example, use the following command:

zypper renamerepo Main Repository (Non-OSS)

To add a repository, run

zypper addrepo URI Alias

How To install OpenSuse 11 directly from Windows

Linux Installation has no been easy task for windows user on windows platform. here come Instlux where it is an opensource application automates linux installation on windows platform. currently user able to use Instlux to install linux distribution either OpenSuse or Ubuntu only.

instlux is a Microsoft Windows application that prepares your computer to directly boot into the openSUSE installation without having to adjust BIOS settings. To use instlux, insert the openSUSE media under Windows. The openSUSE 11.0 Installer setup automatically starts. Choose a language for the installation and follow the instructions on the screen. The language you choose here is also used for the openSUSE installation. instlux is only available on DVD media.

On the next reboot, the Microsoft Windows boot loader launches. Choose openSUSE 11.0 installer to start the openSUSE installation. In order to proceed with the installation, you will be prompted to insert the installation media. The installation proceeds as described below. When Microsoft Windows is booted again, instlux is automatically uninstalled.

This opensource software has been make windows user more painless when migrating windows to linux but unfortunelately now just support OpenSuse and Ubuntu only. Hope this opensource software can support more linux distribution.

Various File Access Methods in Network

The following methods and protocols are well-suited to file transfer and sharing.

FTP

Use FTP (File Transfer Protocol) if you need to exchange files very often and with different users. Set up an FTP server on one system and access it with clients. There are many graphical client applications available for FTP on Windows*, MacOS, and Linux. Depending on how your FTP server is used, enable read and write permissions.

NFS

NFS (Network File System) is a client/server system. A server exports one or more directories that can be imported by a client. Use NFS if you share files very often and for different users. Generally, this protocol is more common in the Linux world than in the Windows world. An NFS export integrates well into your Linux system and you can browse the imported directory structure like any other folder on your local machine. Depending on how you configure it, enable write and read permissions or both on the server. In general, for a home user it makes sense to allow read and write access.

rsync

Use rsync to transfer regularly large volumes of data that does not change considerably. It is available on Linux and Windows. A typical use case for rsync is managing data backups. Refer to the manual page of the rsync command.

Unison

Unison is an alternative to rsync. It is used to regularly synchronize files between different computers but has the advantage to behave bidirectionally. Refer to the manual page of the Unison command. Unison is available on Linux and Windows.

SMB

Samba is a client/server system and an implementation of the SMB protocol. It is usually used in Windows networks, but is supported by several operating systems.

Use Samba if you need to share files very often and with different users, especially to Windows systems. Samba as a Linux-only solution is uncommon, use NFS instead.

SSH

SSH (Secure Shell) enables a secure connection between computer. The SSH suite consists of several commands and uses public key encryption to authenticate users.

Use SSH if you copy files occasionally over an untrusted network and if you are the only user doing so. Although there are graphical user interfaces available, SSH is mainly considered a command line utility and is available on Linux and Windows.

How to switch Languages for a Application in openSuse 11

To run a single application in another language (that has already been installed with YaST), use one of the following commands:

LANG=de_DE application to start any standard X application or GNOME application in German. For other languages, use the appropriate language code. Get a list of all language codes available using the locale -av command.

KDE_LANG=de application to start any KDE application in German. For other languages, use the appropriate language code.

Getting Help in Linux

Nobody is expected to know all options of all commands by heart. If you remember the command name but are not sure about the options or the syntax of the command, choose one of the following possibilities:

--help option

If you only want to look up the options of a certain command, try entering the command followed by a blank and --help. This --help option exists for many commands. For example, ls --help displays all the options for the ls command.

Manual Pages

To learn more about the various commands, you can also use the manual pages. Manual pages also give a short description of what the command does. They can be accessed with man followed by the name of the command, for example, man ls.

The man pages are displayed directly in the shell. To navigate them, move up and down with Page ↑ and Page ↓. Move between the beginning and the end of a document with Home and End. End this viewing mode by pressing Q. Learn more about the man command itself with man man.

Info Pages

Info pages usually provide even more information about commands. To view the info page for a certain command, enter info followed by the name of the command, for example, info ls. You can browse an info page with a viewer directly in the shell and display the different sections, called “nodes.” Use Space to move forward and <— to move backwards. Within a node, you can also browse with Page ↑ and Page ↓ but only Space and <— will take you also to the previous or subsequent node. Like for the man pages, press Q to end the viewing mode.

Note that man pages and info pages do not exist for all commands: sometimes both are available (usually for key commands), sometimes only a man page or an info page exists, sometimes neither of them.

Beauty of Linux Shell

History

By default, Bash “remembers” commands you have entered. This feature is called history. You can browse through commands that have been entered before, select one you want to repeat and then execute it again. To do so, press ↑ repeatedly until the desired command appears at the prompt. To move forward through the list of previously entered commands, press ↓. For easier repetition of a certain command from Bash history, just type the first letter of the command you want to repeat and press Page ↑.

You can now edit the selected command (for example, change the name of a file or a path), before you execute the command by pressing Enter. To edit the command line, just move the cursor to the desired position using the arrow keys and start typing.

You can also search for a certain command in the history. Press Ctrl+R to start an incremental search function. showing the following prompt:

(reverse-i-search)`':

Just type one or several letters from the command you are searching for. Each character you enter narrows down the search. The corresponding search result is shown on the right side of the colon whereas your input appears on the left of the colon. To accept a search result, press Esc. The prompt now changes to its normal appearance and shows the command you chose. You can now edit the command or directly execute it by pressing Enter.

Completion

Completing a filename or directory name to its full length after typing its first letters is another helpful feature of Bash. To do so, type the first letters then press →| (Tabulator). If the filename or path can be uniquely identified, it is completed at once and the cursor moves to the end of the filename. You can then enter the next option of the command, if necessary. If the filename or path cannot be uniquely identified (because there are several filenames starting with the same letters), the filename or path is only completed up to the point where it is getting ambiguous again. You can then obtain a list of them by pressing →| a second time. After this, you can enter the next letters of the file or path then try completion again by pressing →|. When completing filenames and paths with the help of →|, you can simultaneously check whether the file or path you want to enter really exists (and you can be sure of getting the spelling right).

Wild Cards

You can replace one or more characters in a filename with a wild card for pathname expansion. Wild cards are characters that can stand for other characters. There are three different types of these in Bash:

? Matches exactly one arbitrary character
* Matches any number of characters
[set] Matches one of the characters from the group specified in the "set"

How To activate a second monitor in OpenSuse 11

1.In YaST, click Hardware+Graphics Card and Monitor. SaX2 checks the system resources and displays the Card and Monitor Properties dialog.

2.Make sure the monitor is properly detected. If not, use Change to select the appropriate model from the list.

3.Now enable Activate Dual Head Mode and click Configure for further tuning.

4.Make sure the second monitor is properly detected. If not, use Change to select the appropriate model from the list.

5.Decide whether you want to use the second monitor in Cloned Multihead or in Xinerama Multihead mode and click Ok.

6.Test the new configuration before it is applied to the system. Click OK+Test and either Cancel or Save the configuration.

How To create RPM from Source

This is for the Redhat, SuSE and CentOS user out there. Sometimes when you try to search for rpm packages, the only thing that you find is the source file. You create rpm file using this source file:

1. save the source file(usually in tar.gz or tar.bz2 format)
2. extract the files-> tar -xvzf filename.tar.gz or tar -xvjf filename.tar.bz2
3. open the folder of the extracted file and find .spec file
4. type-> rpmbuild -bb filename.spec
5. see the error and continue according to the error until you finish creating rpm files
6. type-> rpm -Uvh filename.rpm to install

Web-based LDAPv3 client

web2ldap is a full-featured Web-based LDAPv3 client written in Python. It is designed to run either as with stand-alone built-in Web server or under the control of another Web server with FastCGI support (e.g. Apache with mod_fastcgi). It has support for various LDAPv3 bind methods and a powerful built-in schema browser. HTML templates are supported for displaying and editing entries, and LDIF templates can be used for quickly adding new entries. A built-in X.509 parser displays a detailed view of certificates and CRLs with active links.

Installing

1. Install all required software on your system.
2. Extract content of archive web2ldap-*.tar.gz to e.g. /usr/local. Regarding directory names under several Unix flavours: Your mileage may vary.
3. Rename /opt/web2ldap- to /opt/web2ldap.
4. Edit configuration modules under [web2ldapdir]/etc/web2ldap/web2ldapcnf/ which contain comments about every configuration parameter. See also the documentation.
5. Optional step to speed start-up time:
      Change current directory to the directory where you extracted web2ldap and invoke python [web2ldapdir]/sbin/compile.py or python -O [web2ldapdir]/sbin/compile.py for compiling all Python sources.
6. Optional step when running under Unix-like systems:
      Choose the right start script for your running mode (see table above) and adjust the path to the Python interpreter executable in the first line of the web2ldap.py script (see also python -h for usage of option -O and -OO for running with optimized bytecode generation).
7. Configure and run WWW server:
      stand-alone
          Unix/Linux:
              [web2ldapdir]/sbin/web2ldap.py
              For a quick start as stand-alone web gateway simply invoke the script at the command-line which outputs the start URL before detaching from console.
          Windows:
              Simply double-click the file [web2ldapdir]/sbin/web2ldap.py.
      Any HTTP server with CGI-FCGI wrapper
          Install cgi-bin/web2ldap.fcgi to CGI-BIN directory of web server.
      Apache with mod_fastcgi
          See configuration directives in file etc/httpd/sample-mod_fastcgi.conf.
      Apache with mod_scgi
          See configuration directives in file etc/httpd/sample-mod_scgi.conf.

How To use Yum

Examples:

To seach for a application: Yum will search all your enabled repos and tell you where you can obtain the package from

yum search application_name

Yum can list all available packages from your enabled repos and tell you where you can obtain the package from:

yum list available

To find out more info about some package

yum info application_name

Installing applications

yum install application_name

Listing rpms : yum can list installed rpms for you from the repos you have enabled

yum list extras

Removing rpms: Yum can remove a application and the dependenciesit installed with tat application. it will not remove depenencies if another application installed needs them.

yum remove application_name

Updating the system: Yum can update the system for you with out user interact if you want it to.

yum update

Not sure if you have upates?

yum check-update

Local install: downloaded a rpm and cannot install it with rpm because of dependencies?

yum localinstall /path/to/the/rpm

Bastille Linux - Installation and configuration

Installing Bastille is easy, since many distributions come with Bastille available as a package, like Debian, Gentoo and Red Hat Fedora. You can also download Bastille in the form of an RPM or as a source file. There are some pre-requisites you will need if you want to run Bastille in Hardening mode (you can run Bastille in Assessment mode without these). These are:

    * perl-Tk and perl-Curses,

    * perl-Tk for Bastille in GUI mode

    * and perl-Curses for the command-line mode.

You can find these pre-requisites in RPM form, or you can install them via CPAN.

After these pre-requisites are installed, you can install Bastille, for example via RPM as:

# rpm -ivh Bastille-3.0.9-1.0.noarch.rpm

Bastille is then executed by running the bastille binary. Run the command with the -x option for GUI Hardening mode, with the -c option for command-line Hardening mode. If you just want to run Bastille in Assessment mode, then run the bastille binary with the –assess option. This will assess the host and then try to launch a browser to display the resulting report. If you do not wish to display the report, you can run Bastille with the –assessnobrowser option, which just generates the report and does not launch a browser. If you wish to revert an already hardened host you can use the -r option like so:

# bastille -r

Bastille can be a powerful tool, particularly for ensuring a consistent security baseline on your Linux hosts. It doesn’t guarantee that your host is secured against all threats, but it does take care of a lot of configuration weaknesses and security configuration that can be time-consuming and complicated. Bastille’s model also means that you can apply the same controls on a number of hosts in a consistent and structured manner. The broad platform and distribution coverage available in the application also means that you can easily harden a variety of hosts without having to worry about differing configuration standards, file locations and default settings. Finally, any tool that helps you with the process of hardening and securing your hosts with the minimum of effort, especially when IT and security resources are sometimes stretched thin, is well worth investing in time to understand and implement.

How to compile Linux kernel

You should be root when running any of the below mentioned commands.
First go to the below link and find the latest kernel version. Currently its - linux-2.6.26

Download it using wget
# wget http://www.kernel.org/pub/linux/kernel/v2.6/linux-2.6.26.tar.gz

And copy it under /usr/src
# cp linux-2.6.26.tar.gz /usr/src

Go to this directory
# cd /usr/src

And extract the kernel from the compressed file. This command will create a new folder called linux-2.6.26
# tar zxf linux-2.6.26.tar.gz

Now go to the directory that contains your new kernel
# cd linux-2.6.26

And get your old configuration
# make oldconfig

If you have qt libraries installed on your system run # make xconfig. This is the graphical configuration system through which you will make all the necessary changes in your kernel. If you have only ncurses installed you may run # make menuconfig
# make xconfig or # make menuconfig

When you have configured everything run make to start compiling your kernel
# make

Then run make modules_install to install your new modules created above.
# make modules_install

And finally create all the necessary files under /boot and also configure grub to include your new kernel
# make install

Reboot and from grub choose the new kernel! If anything goes wrong it means you have made a mistake in the kernel configuration. Boot in with your old kernel and run again make xconfig to do the appropriate changes.
# reboot

Some good links on Fedora Core

What is Fedora

http://fedora.redhat.com/

Fedora screenshots

Nice Fedora Core Screenshots Tour

List of all the programs/libraries that comes with Fedora

http://distrowatch.com/fedora

Download Fedora

http://fedora.redhat.com/Download/mirrors.html

Help for Fedora

Where to look for new programs

Add style elements for your desktop

Quick Postfix Virtual Hosts Configuration

There is 3 main files that need to be modifiy:

    * /etc/mailname : the visible mail name of the system
    * /etc/aliases : Postfix local alias database format
    * /etc/postfix/main.cf : Postfix configuration parameters

/etc/mailname : This is where you set the domain name of the system, has seen by the other. It needs, in most cases, to look like a real domain name, otherwise, the next smtp server on the road might refuse the mails originating from your machine.

In this example, I choose hell.com.

/etc/aliases :
The place you define aliases. For instance, it is quite good to redirect all mail to root to your normal user.

Here:

    # Added by installer for initial user
    root: myuser

    From now on, you will be able to get system notice using mutt with your myuser user.

/etc/postfix/main.cf :

The place we are going to make a few changes. Let’s say I want to be able to relay mail sent to user at mydomain.org to my personnal adress nik@foo.bar.

In the first place I need to define a virtual alias domain.

    virtual_alias_domains = mydomain.org

Then, we need to tell postfix where the alias database is:

    virtual_alias_maps = hash:/etc/postfix/virtual

Adding those 2 lines is sufficient to make your box treat the mail sent to linux.org. Now, we need to tell postfix what to do with the mails.

Create and Edit the file /etc/postfix/virtual and add:

    nik@mydomain.org nikfoobar.org
    localuser@mydomain.org myuser
    @mydomain.org catch-all@foobar.org

At the first line, we say that we want all the mail to nik@mydomain.org to be forwarded to nik@foobar.org.
On the second line we tell postfix to deliver the mails to localuser@mydomain.org to the Unix user myuser.
On line 3, we define a catch-all adress which will forward any mails to mail account to the mail account catch-all@foobar.org.

This is it!

Now we need to regenerate the aliases database as well as the virtual mail aliases dataase. To do so, execute the following commands:

    root@laptop:~#newaliases
    root@laptop:~#postmap /etc/postfix/virtual

And restart postfix:

    root@laptop:~#/etc/init.d/postfix

And you are done Smiling.

Quick and Simple Samba configuration

The first step is to create a share folder on your hard drive; for instance, /disk2/data. After that, you need to edit the smb.conf file, found in /etc/samba, and make it look something like this:

# Global parameters[global]
workgroup = HOME
netbios name = SAMBA
server string = Samba Server %v
map to guest = Bad User
log file = /var/log/samba/log.%m
max log size = 50
socket options = TCP_NODELAY SO_RCVBUF=8192 SO_SNDBUF=8192
preferred master = No
local master = No
dns proxy = No
security = User

# Share[Data]
path = /disk2/data
valid users = nik
read only = No
create mask = 0777
directory mask = 0777

You can copy and paste this into your conf file or make changes to your existing one.

The workgroup name needs to be the workgroup of your Windows computers, or your domain name. The netbios name is what will appear when you access the Linux computer from Windows. I am currently running a Windows domain with this setup, so I have the preferred master and local master set to no to avoid both servers from attempting to be the master browser. This will eliminate network conflicts on your Windows computers that can cause network-related outages.

For the share details, specify the valid users, or set them up later. In that section you can allow users to create their own folder and files for all to access.

The next step is to add users by the following command:

# useradd -c “Nikesh Jauhari” nik
# smbpasswd -a nik
New SMB password: secret
Reenter SMB password: secret
Added user nik

Next, run the testparm command to ensure that the conf file is valid. If it returns no errors, restart Samba with the command /etc/rc.d/rc.samba restart.

Now you’re ready to test Samba. On a Windows computer, you can either map a drive to the Samba server or access the drive using the Start-Run command and typing \\Samba\data, “Samba” being the server name and “data” being the shared folder.

One disclaimer: this setup serves a small network or a home network. For a larger user base and more complex network configuration, you may want to use the documentation provided on the Samba Web site

Making Directory tree with single command

Use mkdir with the `-p’ option to make a subdirectory and any of its parents that do not already exist. This is useful when you want to make a fairly complex directory tree from scratch, and don’t want to have to make each directory individually.

* To make the `a/b/c’ directory — a subdirectory of the `b’ directory, which in turn is a subdirectory of the `a’ directory in the current directory, type:

$ mkdir -p a/b/c [RET]

This makes a `c1′ subdirectory in the directory called `b’, which in turn is in a directory called `a’ in the current directory; if the `b’ or the `c’ directories do not already exist, they are made as well (if you know that `a’ and `b’ both exist, the above command works fine without the `-p’ option).

How To create and use swap file (Adding Swap Space)

Sometimes it is necessary to add more swap space after installation. For example, you may upgrade the amount of RAM in your system from 256 MB to 1 GB, but there is only 256 MB of swap space. It might be advantageous to increase the amount of swap space to 1 GB if you perform memory-intense operations or run applications that require a large amount of memory.

Linux also provides tools to manage your swap space. You can add and remove spaces as you need to, as well as turn them on and off, even while they are being used.

To create a file to be used a swap, you need to first create the file. This is most easily done with the dd command. To create a 65 Mb file, you might have this command (from the the mkswap man-page):

# dd if=/dev/zero of=/swapfile bs=1024 count=65536

which displays:

65536+0 records in
65536+0 records out

Next you have to prepare the file for usage as swap space using the mkswap. The simplest form would be:

# mkswap /swapfile

Now add this file to your swap pool

# swapon /swpafile

Now you can check if swap is added to your system by using following command

# free

How to Automatically reboot server after a kernel panic

Add panic=10 to the kernel command line to reboot with 10 seconds of a kernel error. Be careful with this when setting up new kernels.

It’s possible to change it later with sysctl, or by writing to /proc:

# echo 10 > /proc/sys/kernel/panic

To make it permanent, edit /etc/sysctl.conf and add the below line:

kernel.panic = 10

`sysctl -p` to load the conf file and make permanent.

How do I disable the ping response?

Usually a ping is used to check if a machine is up and to check the network status.

It is a small network packet sent to the machine. If the machine is up, an answer will be sent. The time needed to get the answer is called ping time or round-trip time.

The ping response from an IP indicates the machine is up.

Unfortunately this can be used to quickly scan an IP-range for reachable hosts.

This can be used to find potential hackable machines. If your machine doesn't answer to pings, your chance to be seen is reduced. (That doesn't mean your machine is more secure, the machine is just not that easy to be seen from the internet. Nothing more.)

Add the following line to your init script for the network (the name depends on the distribution you use):

echo 1 >/proc/sys/net/ipv4/icmp_echo_ignore_all

This disables ping responses.

To reenable, use the following command:

echo 0 >/proc/sys/net/ipv4/icmp_echo_ignore_all

To make this permanent set the following into /etc/sysctl.conf (if you have such a file)

net.ipv4.conf.icmp_echo_ignore_all = 1

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