Friday, 21 September 2007

A backup Utility - Rsnapshot

There are many ways to backup Servers. One of the better ways to accomplish this is using rsnapshot. Rsnapshot is nothing but a filesystem snapshot utility for backing up local and remote systems.

Rsnapshot is written in Perl, and depends on rsync। With ssh access, it is possible to backup remote servers.

Why rsnapshot?

We have many familiar ways to generate full backup and copy it to another server which includes ftp, scp and all. But now the question that comes to your mind will be "Why should I use rsnapshot ? or What is so special about this tool?"
Listed below are the major advantages of rsnapshot, which make you feel that it is worth using.
  • Using rsync and hard links, it is possible to keep multiple, full backups instantly available. The disk space required is just a little more than the space of one full backup, plus incrementals. This comes as a criteria when your drive is lacking enough free space to accommodate 3 copies of backup.
  • Depending on your configuration, it is quite possible to set up in just a few minutes. Files can be restored by the users who own them, without the root user getting involved.
  • There are no tapes to change, so once it's set up, you may never need to think about it again.
  • Rsnapshot takes advantage of hard links (multiple directory pointers to the same data) to give the appearance of multiple full backups yet requires only enough disk capacity to store the complete data set plus any changed files. Thus we have the illusion of full hourly, daily, weekly, and monthly backups without having the physical space to hold that many copies.
  • Another benefit is that rsync is cross-platform, so it isn't constrained to *nix systems।

Installation of rsnapshot

Rsnapshot can be installed in a few minutes of time. It requires the following prerequisites.
1) Perl
2) rsync

i). Download the source tarball by useing the command:
ii). Untar the source code package
tar xzvf rsnapshot-1.3.0.tar.gz
iii). Change to the source directory.
cd rsnapshot-1.3.0/
iv). Select the directory to install the files. Usually the files are placed in /usr/local directory and the config files in the /etc directory.

v). Run the configure script
./configure --sysconfdir=/etc
vi). Install the program by
make install
Now rsnapshot is installed under /usr/local, with the config file in /etc।


A sample copy of the rsnapshot config file is provided with the package. We need to just copy the file.
cp /etc/rsnapshot.conf.default /etc/rsnapshot.conf
The directives that need to be configured in rsnapshot.conf

1. snapshot_root
This is the snapshot root directory which holds the file system snapshots.
snapshot_root   /.snapshots/
2. Modify the path to the various programs like rm for removing files, rsync, ssh etc. Usually not much modification is needed here.

3. Specify thebackup intervals.
interval        hourly  6
interval        daily   7
interval        weekly  4
In this example, rsnapshot is taken every four hours, or six times a day (these are the hourly intervals), 7 times a week, 4 times a month. Thus it covers the whole month (4 weeks)

4. Select verbose level, loglevel and logfile path. Typical values used are
verbose         2
loglevel        3
logfile        /var/log/rsnapshot
5. Next main configuration to be done is BACKUP POINTS / SCRIPTS

This is the section where you tell rsnapshot what files you actually want to back up. You put a “backup” parameter first, followed by the full path to the directory or network path you're backing up. The third column is the relative path you want to back up to inside the snapshot root.

backup   /home/          localhost/
backup   /etc          localhost/
backup  /usr/local/      localhost/

For example, take case 1, where the parameter is "backup". We are backing up the /home partition of the server on the rsnapshot root of our server itself. Thus with this backup parameter, a backup of /home is created in /root/.snapshots

In addition to full paths on the same server, we can also backup filesystems on remote systems using rsync over ssh. To get this done,

a) The ssh daemon must be running on the remote server.

b) You must have access to the account you specify the remote machine, in this case the root user on remote server.

c) You must have key-based logins enabled for the root user at remote server, without passphrases.

backup exclude=mtab,exclude=core

In example 1, /home partion of remote server is backed up to the server where snapshot is running. In example 2, similarly /etc partion is backed up, excluding mtab and core directories.
This backup parameter is commonly used in live servers for backup configuration.

Allowing remote logins with no passphrase is a security risk that may or may not be acceptable in your situation. Make sure you guard access to the backup server very carefully! If we wish to perform backup as another user, we could specify the other user instead of root for the source (i.e.

Now with this we have completed the basic configuration of rsnapshot.

6. Testing configuration file.
rsnapshot configtest
If all is well, it should say Syntax OK, or else the errors are shown. We have to use tabs in the config file and not spaces.

7. Test run of rsnapshot
rsnapshot -t hourly
This tells rsnapshot to simulate an "hourly" backup। It will print out the commands it will perform when it runs for real.

Automating rsnapshot using cron job

Edit root's crontab by command
crontab -e
Add the following entries,
0 */4 * * * /usr/local/bin/rsnapshot hourly
30 23 * * * /usr/local/bin/rsnapshot daily

Cron should be timed in a way that the hourly backup is finished before performing the daily backup।

How it works

All backups are stored in the snapshot directory. New directories inside the snapshot root are created when rsnapshot hourly and weekly are run. Thus when rsnapshot hourly is run 6 times, the directories with name hourly.0, hourly.1, ....hourly.5 are created. Similarly when rsnapshot weekly is run, 7 new directories are created namely weekly.0, weekly.1, weekly.2 till weekly.6.

Each subsequent time rsnapshot is run with the hourly command, it will rotate the hourly.X directories, and then “copy” the contents of the hourly.0 directory (using hard links) into hourly.1.

When rsnapshot daily is run, it will rotate all the daily.X directories, then copy the contents of hourly.5 into daily.0.

hourly.0 will always contain the most recent snapshot, and daily.6 will always contain a snapshot from a week ago.
Unless the files change between snapshots, the “full” backups are really just multiple hard links to the same files.
That is how rsnapshot saves disk space. If the file changes at any point, the next backup will unlink the hard link in hourly.0, and replace it with a brand new file.

When weekly, monthly, and yearly intervals defined (in that order), the weekly ones would get updated directly from the filesystem, the monthly ones would get updated from weekly, and the yearly ones would get updated from monthly।


When the aforesaid instructions are followed, rsnapshot installation is quite simple and is very efficient in performing automatic backups of your system. The amount of disk space taken up will be equal to one full backup, plus an additional copy of every file that is changed.


Network Monitoring With ntop: Installation and Configuration

1. Introduction

ntop is a network traffic tool that shows network usage in real time. It displays a list of hosts that are currently using the network and reports information concerning the IP (Internet Protocol) and Fibre Channel (FC) traffic generated by each host. The traffic is sorted according to host and protocol. Protocols (user configurable) include:
* (R)ARP
* Decnet
* AppleTalk
* Netbios
o Telnet
o X11

One of the good things about this tool is that you can use a web browser to manage and navigate through ntop traffic information to better understand network status.

    * a web interface
* limited configuration and administration via the web interface
* reduced CPU and memory usage (they vary according to network size and traffic)
make ntop easy to use and suitable for monitoring various kind of networks.

2. Prerequisites

Ntop 3.2

libpcap is a system-independent interface for user-level packet capture. libpcap provides a portable framework for low-level network monitoring.

3. Download

Please download the G-LIB rpm as well as ntop rpms.

4. Installation

1- Installing G-LIB:

# wget
# rpm -ivh glib-1.2.10-16.i386.rpm

2- Installing ntop:

# wget
# rpm -ivh ntop-3.2-1.el3.rf.i386.rpm

5. Running ntop

1- Initialize ntop:

ntop :That will initialize ntop and it will ask you to enter your username and password.

The default username: admin
Please enter the password for the admin user:
Please enter the password again:
Once the admin password set, you will get a message at the command prompt something like.
"Thu 22 Mar 2007 11:01:04 PM MDT  Admin user password has been set"

2- Start ntop service:

# service ntop start
Starting ntop: [ OK ]

6. Log In To The Web Interface

ntop can be managed through a web interface. You can enter your server address in your web browser:
Now you can monitor your hosts and manage your ntop configuration your admin login.

7. Plugins

The following plugins can be configured for the system through the ntop web interface.
  1. Host Last Seen: This plugin produces a report about the last time packets were seen from each specific host.A note card database is available for recording additional information.
  2. icmpWatch: This plugin produces a report about the ICMP packets that ntop has seen. The report includes each host, byte and per-type counts (sent/received).
  3. snmpPlugin: This plugin is used to monitor host traffic using the SNMP protocol.
  4. Round Robin Database: This plugin is used to setup, activate and deactivate ntop's rrd support. This plugin also produces the graphs of rrd data, available via a link from the various 'Info about host xxxxx' reports.
  5. NetFlow: This plugin is used to setup, activate and deactivate NetFlow support. ntop can both collect and receive NetFlow V1/V5/V7/V9 and IPFIX (draft) data. Received flow data is reported as a separate 'NIC' in the regular ntop reports.
  6. sFlow: This plugin is used to setup, activate and deactivate ntop's sFlow support. ntop can both collect and receive sFlow data.
  7. PDAPlugin: This plugin produces a minimal ntop report, suitable for display on a pda.

. References


Installing and Configuring Nagios

1) Getting Nagios

You need root access on the server, where you would like to install Nagios. Login as root.

Create a directory for downloads.

#mkdir -p /usr/src/backs/nagios
#cd /usr/src/backs/nagios

Download source of nagios and nagios-plugins at

#wget http://keihanna।dl।

2) Compilation and installation of Nagios

Login as root and create a user, say "nagios"
#adduser nagios
#passwd nagios
Changing password for user nagios.
New UNIX password:
Retype new UNIX password:
passwd: all authentication tokens updated successfully.

In some servers normal users may not have permission to use 'mail' inorder to send alerts.
usermod -G mail nagios
Make a directory for working with the source code.
mkdir -p /usr/src/works/nagios
cd /usr/src/works/nagios/
tar -zxvf /usr/src/backs/nagios/nagios-1.2.tar.gz
cd nagios-1.2/
The default is fine for normal operation. for details see the file 'INSALL'.
./configure --prefix=prefix --with-cgiurl=cgiurl --with-htmurl=htmurl
--with-nagios-user=someuser --with-nagios-grp=somegroup
make all
make install
make install-init # Needed to add the service 'nagios'.
make install-commandmode
make install-config
Install the plugins
cd ../
tar -zxvf /usr/src/backs/nagios/nagios-plugins-1.3.1.tar.gz
cd nagios-plugins-1.3.1/
NOTE:- For mysql and postgresql plugins to work, their libraries have
to be installed. so to avoid installing those we will use 'check_tcp'
Instead later with seperate port for mysql and postgresql.
make check
make install

Libraries will be installed in '/usr/local/nagios/libexec' position by the default installation. If there is no contents do the following.

 mkdir /usr/local/nagios/libexec
mv /usr/lib/nagios/plugins/* /usr/local/nagios/libexec/
ln -s /lib/ /lib/

3) Post install Configuration of Nagios

Edit apache's httpd.conf file. (the location of the httpd.conf file may differ)
vim /etc/httpd/conf/httpd.conf
Add the following line at the end of the file.
Include /etc/httpd/conf/nagios.conf
Create the file '/etc/httpd/conf/nagios.conf'.
vi /etc/httpd/conf/nagios.conf
Add the following contents to this file.
ScriptAlias /nagios/cgi-bin/ /usr/local/nagios/sbin/

AllowOverride AuthConfig
Options ExecCGI
Allow from all
Order allow,deny

Alias /nagios/ /usr/local/nagios/share/

Options None
AllowOverride AuthConfig
Order allow,deny
Allow from all


Make sure the updations done with http is fine and restart apache.
#service httpd restart
Create '.htaccess' file in '/usr/local/nagios/share/' and '/usr/local/nagios/sbin/'.
#touch /usr/local/nagios/share/.htaccess
#touch /usr/local/nagios/sbin/.htaccess
Add the following contents to both these files.
AuthName "Nagios Access"
AuthType Basic
AuthUserFile /usr/local/nagios/etc/htpasswd.users
require valid-user

Create the username, password for logging into the Nagios interface.

htpasswd -c /usr/local/nagios/etc/htpasswd.users nagiosadmin
ls -l /usr/local/nagios/etc/htpasswd.users
Make it available for the user who runs httpd.
chmod o+r /usr/local/nagios/etc/htpasswd.users
Restart the httpd service.
service httpd restart

5)Advanced Nagios Configurations.

Rename the sample files to the real names.
cd /usr/local/nagios/etc/
for i in *sample ; do mv $i `echo "$i" |sed s/-sample//` ; done
Edit the main conf file, nagios.cfg. and change only these lines.
Make these Cgi specific changes in cgi.cfg.

Add servers that need to be monitored

Make the Host specific changes to the hosts.cfg.
 Generic host definition template
define host{
name generic-host
notifications_enabled 1
event_handler_enabled 1
flap_detection_enabled 1
process_perf_data 1
retain_status_information 1
retain_nonstatus_information 1

register 0

define host{
use generic-host ; Name of host
template to use

check_command check-host-alive
max_check_attempts 10
notification_interval 120
notification_period 24x7
notification_options d,u,r
Repeat for all the hosts we want to check.

Group them in hostgroups.cfg

define hostgroup{
members <,,..>
Repeat for all the hosts groups.

Specify the services that need to be checked

Edit the details of all the services, we want checked by Nagios in services.cfg.
 Generic service definition template
define service{
name generic-service
active_checks_enabled 1
passive_checks_enabled 1
parallelize_check 1
obsess_over_service 1
check_freshness 0
notifications_enabled 1
event_handler_enabled 1
flap_detection_enabled 1
process_perf_data 1
retain_status_information 1
retain_nonstatus_information 1
register 0

define service{
use generic-service
is_volatile 0
check_period 24x7
max_check_attempts 3
normal_check_interval 3
retry_check_interval 1
notification_interval 120
notification_period 24x7
notification_options w,u,c,r
Repeat for each service on each host.

Specify Alert Contacts

In order to specify details of the contacts for alerts, we need to edit contacts.cfg.
 'nagios' contact definition
define contact{
service_notification_period 24x7
host_notification_period 24x7
service_notification_options w,u,c,r
host_notification_options d,u,r
service_notification_commands notify-by-email,notify-by-epager
Repeat for all contacts.

Group the contacts

Edit contactgroups.cfg, in order to specify groups of contacts.
define contactgroup{
Repeat for all groups to include all contacts

Escelating with nagios

If you need to send selective alerts, for example when critical issues occur, simply configure the escalations.cfg file.
define serviceescalation{
service_description <>
first_notification 2
last_notification 6
contact_groups <>
notification_interval 0
Repeat for all escalations Once again, check all the files, nagios.cfg cgi.cfg hosts.cfg hostgroups.cfg, services.cfg, contacts.cfg, contactgroups.cfg, escalations.cfg and checkcommands.cfg Restart httpd and then Nagios.
service httpd restart
Add Nagios to system services.
chkconfig --add nagios
service nagios restart
Check for any errors reported, and solve them one by one if any.
Enable nagios in runlevels, so that it starts on boot.
chkconfig nagios on
Create cron.daily entry if we want to restart the service daily. Here is the script.
vi etc/cron.daily/nagios-restart.cron
/sbin/service nagios restart >/dev/null 2>&1

Make it executable
chmod +x etc/cron.daily/nagios-restart.cron
And finally, Check if nagios is working fine.!!! ;-)

Tuesday, 18 September 2007

Answer to the Question of "what is the difference between Linux & Windows?"


That is a question that has many different answers, depending on what aspect of Windows or Linux you want to know about. Both are what are known as Operating Systems, and in this case, both are designed to work on the same type of hardware -- PCs, otherwise known as IBM Compatibles. There are enormous differences in the way that they behave at a technical level, but I suspect what you really want to know is how they differ from the perspective of an end user. This makes any answer I give somewhat subjective (users have different preferences and expectations of their computers), but I will do my best to give an answer that is generally accepted by the IT community.

Windows was introduced by Microsoft in 1983, and has been the dominant Operating System available for the PC since the early-nineties. As such, Microsoft has enjoyed great financial success, and Windows has had many years and incredible fiscal resources to evolve to meet the demands of the mass-market. There is an staggeringly rich set of features here, from very explicit, step-by-step user interfaces for the first time computer user, to powerful interfaces for the computer professional, and everything in between. By contrast, Linux achieved notoriety a bit later, in the mid-nineties, with a distribution known as Redhat, and although Linux was built on more mature, stable underpinnings (Unix), it did not enjoy nearly the same marketing or development budget that Microsoft threw behind Windows. In fact, the developers of Linux are commonly credited as founding the Open Source Software movement, which is the idea that software can be made better through the free sharing of its source code. In this philosophy, programmers often volunteer their time to develop software for free, as was done with Linux, and Linux is still available for free in its more basic forms. Companies like Redhat only make money by "packaging" Linux with printed documentation, extra software utilities, and setup wizards designed to make the installation of Linux and its subsequent software packages easier. Even so, the amount of money they are able to generate this way is paltry compared to the wealth of Microsoft (which makes most company's financials look paltry). Because of this, the marketing behind Linux has been miniscule compared to that of Windows, and its lack of acceptance among less technical users reflects this. A large reason is because Windows has established a very deeply-ingrained (and some have argued unfairly controlling) relationship with PC hardware manufacturers, ensuring that almost every new PC ships with Windows installed from day one. Given that they must satisfy the demands (though perhaps less than perfectly) of the majority of novice computer users, and add to that the amount of time and money that Windows has enjoyed to make itself accessible to these users, and it is easy to see why Windows is generally regarded as superior to Linux in the area of accessibility to novices. There are graphic user interfaces (abbreviated as GUI) present for almost everything you could want to do, and there is almost always more than one way to do it. In fact, one common criticism of Windows is that so many features have been layered on top of one another over the years, that it has become an overly-complicated, almost labyrinthine user experience. By contrast, some may find Linux to be more streamlined; however, there are still many equivalent features in Windows for which Linux does not provide a GUI, and the user is forced to type textual instructions into a command-line interface, or shell. While many power users consider this a plus, it is unrealistic to demand this of novice computer users, and novice users should bear this strongly in mind. All this being said, Linux still shines brilliantly in some areas that Windows seems to consistently flounder. Because the underlying architecture of Linux is more mature, stable, and secure than Windows, Linux "crashes" and "freezes" significantly less often, and can run continuously without problems for months or even years without being "rebooted". In addition, Linux does not suffer from the same security flaws as Windows, and your chances of contracting a virus, a worm, or some other form of predatory software is much lower. On an more subjective note, I suspect that given the same time and monetary advantages as Windows, Linux might have easily developed into a superior operating system in every regard.

As it stands today, they each have pros and cons. Windows is widely accepted everywhere, boasts an enormous plethora of GUIs, and has millions of software packages that run under it. But it is buggier, less secure, and sometimes feels cavernous. Linux is solid and smooth running, and feels more stream-lined to many. But what technical users call stream-lined, novices may interpret as spare, and sometimes barren or just plain missin. There are also fewer software packages available for it currently, though many of those that are available are free. As time goes by, and the Open Software Community develops more for Linux, these differences will shrink, but until there is financially powerful, unifying force (company) behind Linux, this author thinks it is doubtful they will go away all together.


Linux is open source, free under GNU, Windows is Lincesed os. Windows is developed by Microsoft. Whereas linux has many distributors such as redhat, mandrake etc. Linux is more secure, windows is less secure than linux in case of virus, worms.

== Answer ==

Linux has many distributors like Radhat, mandrake, Corel etc whereas windows has only Micrsoft. One more major difference is Linux works on both GUI & Console mode but windows only GUI. LINUX have multiuser, multitasking, multiprocessing, multiprogramming features


there are many differences, one being that all versions of linux are not the same, with the many distributions about, they all look the same but run a little differencetly, such as the way that the software is installed, one some, they use RPM packages which, with a package manager, install them selves when u ask them, others you would have to unpack the souce code, build the program and then install it... i personally use Gentoo (kinda new to it but loving it) its install system is called portage, with simple commands.. it has an online package database that stores all of the current applications and plugins that the portage people know of (mostly notified by the developers that it exists). To install something, say you wanted to have an mp3 player, you could type in the console emerge -S mp3.... this would search the database for mp3 in the package description and tell u a list of packages that the string was found in, you could tell it to pretend to install it and so on.... there is more information about this on I personally swapped to Linux because of all the problems i had with windows, even with a fresh install i was having different problems to what i had in a previous install. Another thing to point out is that the linux developers develop linux not for money but as a hobby, making the code great is what they enjoy, creating usefull items wanted by the public. There is a vast network of forums and irc channels dedicated to linux and you can find the solution to almost any problem there. I will say that it takes longer to set linux up than windows, but if you look at the time spent maintaining the two OS, you will see that that time is swiftly made up. :D


Linux is more secured when compared to windows by giving the accessing rights.where as in windows we have just password security.


FYI regarding viruses. There's an old joke that asks "why do people rob banks,..ans: that's where the money is!"....the reason why Microsoft gets dinged so much is that windows is probably running on >95% of all consumer desktop computers. Many feel that if Linux ever competes, it will garner the attention of virus hackers, and also be plagued by viruses, worms, trojans, etc. Even now, there are websites (albeit not well known) that track the development of Linux viruses...aka for instance.

Another reason WHY linux is not affected by viruses, is that its code has been open source for more than a decade, tested by people all around the world, and not by a single development team like in the case of Windows. I mean to say that, probability of finding (and thus fixing) exploitable holes in Linux is very high. So there is extremely enhanced security and lesser chances of exploits.

Again, theres one more good reason. Linux was originally meant to be a multi-user OS. Windows was meant for the end-user. After a few years, Microsoft realised the fact and tried to change their primary design goal. After building two floors, if you try to replace bricks, you would end up with high instability. This is what Windows is experiencing.


An easy and fun way to try linux is to go to ...just that way, no www. You can order a free, two disk set of Ubuntu linux. One is a live CD that runs over windows, in RAM, and doesn't change your system at all..the other is an install disk. I've used the live CD on two XP machines and they both ran flawlessly. When you want to quit, just go to logout under system tools, and shut down. Ubuntu will turn itself off, eject the disk, and turn of your PC. Remove the disk, boot up, and you're running your Windows again. Details at Note: They even pay the shipping.


Windows and Linux are two different operating systems. The purpose of an operating system is to: 1. control all the hardware components that are part of your computer. 2. manage a computer's ability to do several things at once 3. provide a base set of services to programs to keep software manufacturers from have to reinvent the wheel a million times for the same thing.

The Linux operating system was developed from a base of Unix (another operating system) after the Unix systems stopped being free. The Linux people believe in free and open software, and so they "reinvented" Unix, and improved it slightly to make Linux.

Windows is a proprietary operating system owned by Microsoft. It was developed independently from Unix, and its internal details are much different. They should perform the same tasks, however at the deepest levels, details differ, and so a program written to run on Windows will not run on Linux, and vice versa.

Widows comes in several "flavors", like Windows NT, Windows 2000, and Windows XP, all of which are slightly different, but share enough in common that programs written for one flavor will run on the others 99.9% of the time.


Linux is a open-source OS. It's build by "amateurs". people can change code and add programs which will help to use your computer better. It's designed as a reaction on the monopoly position of windows. you can't change any thing in windows. you can't even see which processes do what and build your onw extension. Linux wants the programmers to extend and redesign it's OS time after time, so it beats Windows or at least is as good as windows, but whit open-source, so you can see what happens and you can edit the OS


Difference Between Linux and Windows

1) Linux is a open-source OS.People can change code and add programs which will help to use your computer better. It's designed as a reaction on the monopoly position of windows. you can't change any thing in windows. you can't even see which processes do what and build your onw extension. Linux wants the programmers to extend and redesign it's OS time after time, so it beats Windows or at least is as good as windows, but whit open-source, so you can see what happens and you can edit the OS

2) All the flavors of Windows come from Microsoft, the various distributions of Linux come from different companies (i.e LIndows , Lycoris, Red Hat, SuSe, Mandrake, Knopping, Slackware).

3) Linux is customizable in a way that Windows is not. For example,NASlite is a version of Linux that runs off a single floppy disk and converts an old computer into a file server. This ultra small edition of Linux is capable of networking, file sharing and being a web server.

4) For desktop or home use, Linux is very cheap or free, Windows is expensive. For server use, Linux is very cheap compared to Windows. Microsoft allows a single copy of Windows to be used on only one computer. Starting with Windows XP, they use software to enforce this rule (activation). In contrast, once you have purchased Linux, you can run it on any number of computers for no additional charge.

5) You have to log on to Linux with a userid and password. This is not true of Windows. Typically Windows 9x does not ask for a userid/password at boot time and, even if it does, this can be easily bypassed. In general, Windows NT, 2000 and XP do require a userid/password to log on. However Windows 2000 and XP can be configured with a default userid and password so they boot directly to the Windows desktop. Windows XP, 2000 and Linux all support different types of users. Windows XP Home Edition supports Administrator class users that have full and total access to the system and restricted users that, among other restrictions, can't install software. Windows XP Pro and Windows 2000 support additional levels of users and there are groups of system privileges that can be assigned to a particular user. In Linux, the user with full and total access is called root, everyone else is a normal user. The options for Linux security privileges don't seem to me to be as robust as in Windows 2000 and XP Pro, they are focused on files and directories (can you read, update and execute files). Linux has a concept of a group of users that Windows does not, but again the privileges associated with a group are all file/directory related.

6) Linux has a reputation for fewer bugs than Windows

7) Windows must boot from a primary partition. Linux can boot from either a primary partition or a logical partition inside an extended partition. Windows must boot from the first hard disk. Linux can boot from any hard disk in the computer.

8) Windows uses a hidden file for its swap file. Typically this file resides in the same partition as the OS (advanced users can opt to put the file in another partition). Linux uses a dedicated partition for its swap file (advanced users can opt to implement the swap file as a file in the same partition as the OS).

9) Windows uses FAT12, FAT16, FAT32 and/or NTFS with NTFS almost always being the best choice. Linux also has a number of its own native file systems. The default file systeAll the file systems use directories and subdirectories. Windows separates directories with a back slash, Linux uses a normal forward slash. Windows file names are not case sensitive. Linux file names are. For example "abc" and "aBC" are different files in Linux, whereas in Windows it would refer to the same file. Case sensitivity has been a problem for this very web page, the name of which is "Linux.vs.Windows.html". At times, people have tried to get to this page using "" (all lower case) which resulted in a Page Not Found error. Eventually, I created a new web page with the name in all lower case and this new page simply re-directs you to the real page, the one you are reading now (with a capital L and W). m for Linux used to be ext2, now it is typically ext3.

10) Windows and Linux use different concepts for their file hierarchy. Windows uses a volume-based file hierarchy, Linux uses a unified scheme. Windows uses letters of the alphabet to represent different devices and different hard disk partitions. Under Windows, you need to know what volume (C:, D:,...) a file resides on to select it, the file's physical location is part of it's name. In Linux all directories are attached to the root directory, which is identified by a forward-slash, "/". For example, below are some second-level directories: /bin/ ---- system binaries, user programs with normal user permissions /sbin --- executables that need root permission /data/ --- a user defined directory /dev/ ---- system device tree /etc/ ---- system configuration /home/ --- users' subdirectories /home/{username} akin to the Windows My Documents folder /tmp/ ---- system temporary files /usr/ ---- applications software /usr/bin - executables for programs with user permission /var/ ---- system variables /lib --- libraries needed for installed programs to run

11) Both support the concept of hidden files, which are files that, by default, are not shown to the user when listing files in a directory. Linux implements this with a filename that starts with a period. Windows tracks this as a file attribute in the file metadata (along with things like the last update date). In both OSs the user can over-ride the default behavior and force the system to list hidden files.

12) Windows started with BAT files (a combination of OS commands and optionally its own language) and then progressed to Windows Scripting Host (WSH) which supports two languages, JavaScript and VB Script. Linux, like all Unix variants, provides multiple scripting languages, referred to as shell scripts. In general, the Linux scripting languages are older and cruder than WSH but much more powerful than BAT files. They tend to use special characters instead of English commands and don't support objects (this only matters to programmers). One scripting language that can run on both Linux and Windows is PHP. It always has to be installed under Windows, it may have to be installed under Linux. PHP is typically found running on Linux based web servers in combination with Apache, but it is capable of running "client side" (on your computer).

13) Every computer printer ships with drivers for last last few versions of Windows (at the time it was manufactured). Running the printer on a very old or too new version of Windows may or may not work. Still, this a far better situation than with Linux which does not support as many printers as Windows. In an environment with many Linux users, shared network printers a tech support staff, this should not be an issue as you can limit yourself to well supported printers. Home users of Linux however, will no doubt suffer from the relatively poor support for printers.

14) Windows allows programs to store user information (files and settings) anywhere. This makes it impossibly hard to backup user data files and settings and to switch to a new computer. In contrast, Linux stores all user data in the home directory making it much easier to migrate from an old computer to a new one. If home directories are segregated in their own partition, you can even upgrade from one version of Linux to another without having to migrate user data and settings.


Linux is based on an adaptation of Unix, started by a Finn named Linus Torvalds when he was a student. Through the manifestation of the Open Source model, too involved to explain here, it is continually upgraded by volunteers, and is produced in a wide variety of "flavors" or distributions. Linux is always free. To get a handle on the Open Source movement, check out . There's a ton of information available, just google linux once and you'll see. It's reputed to be a very stable, dependable operating system, generally uses fewer resources to do the same task, and can be had in a form to do anything from server tasks to compiling code. In addition, many versions come with 1,000 or more open source programs to do anything from word processing to photo editing, all free. is a good place to grab some free programs that are open source, but written to run on windows. You'll be surprised at how good they are. Windows, on the other hand, is based on DOS (disk operating system) that was borrowed from IBM, if memory serves. Windows 3.1 is the last heavy DOS operating system from Microsoft. For Windows 95 they pile a graphical user interface on top of DOS, the gui we hear about. It worked, sorta, and folks who didn't like command line stuff ate it up. It is a strictly commercial program, and includes a minimal amount of free software, like notepad or wordpad. Microsoft keeps making them bigger and more expensive, and we all keep buying them. I'm not looking forward to being Longhorned. Both Linux and Microsoft have their advantages. One difference is that if you obtain or download one linux disk, you can use it on as many machines as you like, and it's free. With Microsoft, you pay a good chunk of cash for their operating sytems, and you can use it on one machine and one only. With the advent of XP, they force you to "reactivate" XP every time you install it. You can only do so a certain number of times. Each has it's positive and negative attributes. It will be interesting in the coming years to see if Linux continues to grow as it has. Check out this articla about XP if you think I'm kidding. Personally, I'm really curious about Linux. Free is good. Good luck.


Linux is an open source operating system that, until fairly recently, was only used on servers. Now it is used on Mac OS X computers, and more people are starting to use it on computers that aren't servers. It is very secure, efficient, and flexible.

Microsoft Windows is a closed-source operating system created by Bill Gates, supreme ruler of the earth. It is gradually losing it's grip on the market because it is insecure, slow, and wasteful.

Why we use LINUX ????

Linux is better than Windows because ...

0. Linux developers don't disguise their listings on Google by pretending they're about Windows. Actual Google listing:

Linux Download
Customize your Operating System. Learn more about Windows Embedded.

1. Linux screen blankers don't turn your PC into a Microsoft ad.

2. It isn't fair to say the Windows GUI is a poor copy of X-windows. Actually it's a poor copy of the Mac.

3. Windows, being a commercial product, is so ridiculously insecure an undergraduate student in the Phillipines could accidentally bring down millions of systems. Microsoft's answer to this was that if anyone is stupid enough to click on an icon generated by Microsoft's own software, they deserve what they get. Unix and Linux have not had a self-propagating virus or worm in over 10 years. Of course Windophiles will say that's only because no one ever tries to write a Unix virus, but we know of a few people in Redmond who would do it if they could. Unix was used for years at universities where many of the authorized users were students intentionally trying to crash the system. Now that's reliability

4. You are charged between $100 and $200 for Windows every time you buy a PC (Microsoft dosen't want you to know exactly how much) even if you're replacing a PC that already has Windows. If you want to run a server you have to pay extra for Windows NT. Then you have to pay extra for a server. With Linux, everything is included for one price. And that price is nothing. Nada. Zip. Zero.

5. Windows protects you from the fearsome experience of being able to see exactly how the operating system works. Just "Wait while setup prepares the Install Shield Wizard".

6. With Linux the source code is included. With Windows having the source code would be illegal, (unless you pay a lot more than you already pay, and even then Microsoft developers get more than you do).

7. Windows requires you agree to a license that no one has ever had the endurance to read all the way through. For all you know, it might include a demand for your first born child. With Linux, the license says: "You can do anything you want with this software. Enjoy."

8. Linux is fully compatible with the Posix standard. Windows is partially compatible with earlier versions of Windows.

9. Unix mail allows you to communicate with anyone. Microsoft mail allows you to communicate with anyone who also has Microsoft Mail. (Yes, we know you can manually enter an SMTP address in a message, but the addressing database is designed to make it virtually impossible to ensure that other users will automatically send to the SMTP address. You can forward your mail, but then reply dowsn't work.)

10. Linus Torvalds is a system programming specialist (and a nice guy) who spent 7 years as a graduate student in Helsinki so he could develop Linux for you. Bill Gates is a marketing specialist (and an egotist) who built a 40 room house with your money.

11. Linux allows you to reboot when you want to. Windows forces you to reboot when you install new software, try to actually use your software, or sometimes just because the sky is blue. - contributed by Derric Tubbs

12. Linux runs on way more hardware than Windoze: SPARC, MIPS, ARM, PowerPC, Alph a, etc. Windoze runs on x86, The NT flavour runs on one real processor in addition (Alpha). That's a small pool of hardware to base a future on, especially as even Intel has calculated that x86 is approaching end-of-life. -- contributed by Willem de Lind van Wijngaarden

13 The Navy's "Smart Ship" based on Windows NT failed so totally it had to be TOWED BACK TO PORT TWICE just because the computers wouldn't work. (This has not happened with another Navy project, a Unix-based submarine control system.) But the DOD still insists on using Microsoft as a "sole source" even though "sole source" procurement is supposed to be avoided and many of its own people would like to use software that's cheaper and better.

14. Microsoft won't let anyone look at its algorithms, so it took painstaking study to determine that the statistical procedures in Excel are inaccurate, invalidating the results of anyone unwise enough to use it. Of course you won't see this in a Microsoft ad. (McCullough, BD, Computational Statistics and Data Analysis v31 (1999) 27-37.)

15. Linus Torvalds didn't have to pay off George Bush's staff to ensure Bush will drop the Justice Department suit against Microsoft if he's elected. ("Ralph Reed, a senior consultant to Gov. George W. Bush's presidential campaign, [and former head of the Christian Coalition] apologized today for lobbying the governor on behalf of the Microsoft Corporation and promised not to lobby him again." -- New York Times, 4-11-00)

16. NT means "not today".

History of Linux

Table of Contents

a. In The Beginning

b. New Baby in the horizon

c. Confrontation and development

d. A Decade of Linux

e. Tux: The Spirit of Linux

f. Some Linux Cookies

g. Timeline

h. Links

i. Acknowledgments

a. In The Beginning

It was 1991, and the ruthless agonies of the cold war were gradually coming to an end. There was an air of peace and tranquility that prevailed in the horizon. In the field of computing, a great future seemed to be in the offing, as powerful hardware pushed the limits of the computers beyond what anyone expected.

But still, something was missing.

And it was the none other than the Operating Systems, where a great void seemed to have appeared.

For one thing, DOS was still reigning supreme in its vast empire of personal computers. Bought by Bill Gates from a Seattle hacker for $50,000, the bare bones operating system had sneaked into every corner of the world by virtue of a clever marketing strategy. PC users had no other choice. Apple Macs were better, but with astronomical prices that nobody could afford, they remained a horizon away from the eager millions.

The other dedicated camp of computing was the Unixworld. But Unix itself was far more expensive. In quest of big money, the Unix vendors priced it high enough to ensure small PC users stayed away from it. The source code of Unix, once taught in universities courtesy of Bell Labs, was now cautiously guarded and not published publicly. To add to the frustration of PC users worldwide, the big players in the software market failed to provide an efficient solution to this problem.

A solution seemed to appear in form of MINIX. It was written from scratch by Andrew S. Tanenbaum, a US-born Dutch professor who wanted to teach his students the inner workings of a real operating system. It was designed to run on the Intel 8086 microprocessors that had flooded the world market.

As an operating system, MINIX was not a superb one. But it had the advantage that the source code was available. Anyone who happened to get the book 'Operating Systems: Design and Implementation' by Tanenbaum could get hold of the 12,000 lines of code, written in C and assembly language. For the first time, an aspiring programmer or hacker could read the source codes of the operating system, which to that time the software vendors had guarded vigorously. A superb author, Tanenbaum captivated the brightest minds of computer science with the elaborate and immaculately lively discussion of the art of creating a working operating system. Students of Computer Science all over the world pored over the book, reading through the codes to understand the very system that runs their computer.

And one of them was Linus Torvalds.

b. New Baby in the Horizon

In 1991, Linus Benedict Torvalds was a second year student of Computer Science at the University of Helsinki and a self-taught hacker. The 21 year old sandy haired soft-spoken Finn loved to tinker with the power of the computers and the limits to which the system can be pushed. But all that was lacking was an operating system that could meet the demands of the professionals. MINIX was good, but still it was simply an operating system for the students, designed as a teaching tool rather than an industry strength one.

At that time, programmers worldwide were greatly inspired by the GNU project by Richard Stallman, a software movement to provide free and quality software. Revered as a cult hero in the realm of computing, Stallman started his awesome career in the famous Artificial Intelligence Laboratory at MIT, and during the mid and late seventies, created the Emacs editor. In the early eighties, commercial software companies lured away much of the brilliant programmers of the AI lab, and negotiated stringent nondisclosure agreements to protect their secrets. But Stallman had a different vision. His idea was that unlike other products, software should be free from restrictions against copying or modification in order to make better and efficient computer programs. With his famous 1983 manifesto that declared the beginnings of the GNU project, he started a movement to create and distribute softwares that conveyed his philosophy (Incidentally, the name GNU is a recursive acronym which actually stands for 'GNU is Not Unix'). But to achieve this dream of ultimately creating a free operating system, he needed to create the tools first. So, beginning in 1984, Stallman started writing the GNU C Compiler(GCC), an amazing feat for an individual programmer. With his legendary technical wizardry, he alone outclassed entire groups of programmers from commercial software vendors in creating GCC, considered as one of the most efficient and robust compilers ever created.

Richard Stallman

Richard Stallman, father of the GNU Project

By 1991, the GNU project created a lot of the tools. The much awaited Gnu C compiler was available by then, but there was still no operating system. Even MINIX had to be licensed.(Later, in April 2000, Tanenbaum released Minix under the BSD License.) Work was going the GNU kernel HURD, but that was not supposed to come out within a few years.

That was too much of a delay for Linus.

In August 25, 1991 the historic post was sent to the MINIX news group by Linus .....

From: torvalds@klaava.Helsinki.FI (Linus Benedict Torvalds)
Newsgroups: comp.os.minix
Subject: What would you like to see most in minix?
Summary: small poll for my new operating system
Message-ID: <>
Date: 25 Aug 91 20:57:08 GMT
Organization: University of Helsinki

Hello everybody out there using 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.I'd like any feedback on
things people like/dislike in minix, as my OS resembles it somewhat
(same physical layout of the file-system(due to practical reasons)
among other things). I've currently ported bash(1.08) and gcc(1.40),and
things seem to work.This implies that I'll get something practical within a
few months, andI'd like to know what features most people would want. Any
suggestions are welcome, but I won't promise I'll implement them :-)
Linus (
PS. Yes - it's free of any minix code, and it has a multi-threaded fs.
It is NOT protable (uses 386 task switching etc), and it probably never
will support anything other than AT-harddisks, as that's
all I have :-(.

As it is apparent from the posting, Linus himself didn't believe that his creation was going to be big enough to change computing forever. Linux version 0.01 was released by mid September 1991, and was put on the net. Enthusiasm gathered around this new kid on the block, and codes were downloaded, tested, tweaked, and returned to Linus. 0.02 came on October 5th, along with this famous declaration from Linus:

From: torvalds@klaava.Helsinki.FI (Linus Benedict Torvalds)
Newsgroups: comp.os.minix
Subject: Free minix-like kernel sources for 386-AT
Message-ID: <>
Date: 5 Oct 91 05:41:06 GMT
Organization: University of Helsinki
Do you pine for the nice days of minix-1.1, when men were men and wrote their own device drivers?
Are you without a nice project and just dying to cut your teeth on a OS you can try to modify for your
needs? Are you finding it frustrating when everything works on minix? No more all-nighters to get a nifty program working? Then this post might be just for you :-)
As I mentioned a month(?)ago, I'm working on a free version of a minix-lookalike for AT-386 computers. It has
finally reached the stage where it's even usable (though may not be depending on
what you want), and I am willing to put out the sources for wider distribution. It is just version 0.02 (+1 (very
small) patch already), but I've successfully run bash/gcc/gnu-make/gnu-sed/compress etc under it.
Sources for this pet project of mine can be found at ( in the directory /pub/OS/Linux.
The directory also contains some README-file and a couple of binaries to work under linux
(bash, update and gcc, what more can you ask for :-). Full kernel source is provided, as no minix code has been
used. Library sources are only partially free, so that cannot be distributed currently. The system is able to compile
"as-is" and has been known to work. Heh. Sources to the binaries (bash and gcc) can be found at the
same place in /pub/gnu.

Linux version 0.03 came in a few weeks. By December came version 0.10. Still Linux was little more than in skeletal form. It had only support for AT hard disks, had no login ( booted directly to bash). version 0.11 was much better with support for multilingual keyboards, floppy disk drivers, support for VGA,EGA, Hercules etc. The version numbers went directly from 0.12 to 0.95 and 0.96 and so on. Soon the code went worldwide via ftp sites at Finland and elsewhere.

c. Confrontation & Development

Linus displays Linux running on a notebook pc

Soon Linus faced some confrontation from none other than Andrew Tanenbaum, the great teacher who wrote MINIX. In a post to Linus, Tanenbaum commented:

"I still maintain the point that designing a monolithic kernel in 1991 is a fundamental error. Be thankful you are not my student. You would not get a high grade for such a design :-)"
(Andrew Tanenbaum to Linus Torvalds)

Linus later admitted that it was the worst point of his development of Linux. Tanenbaum was certainly the famous professor, and anything he said certainly mattered. But he was wrong with Linux, for Linus was one stubborn guy who won't admit defeat.

Tanenbaum also remarked that : "Linux is obsolete".

Now was the turn for the new Linux generation. Backed by the strong Linux community, Linus gave a reply to Tanenbaum which seems to be most fitting:

Your job is being a professor and researcher: That's one hell of a good excuse for some of the brain-damages of minix.
(Linus Torvalds to Andrew Tanenbaum)

And work went on. Soon more than a hundred people joined the Linux camp. Then thousands. Then hundreds of thousands. This was no longer a hackers toy. Powered by a plethora of programs from the GNU project, Linux was ready for the actual showdown. It was licensed under GNU General Public License, thus ensuring that the source codes will be free for all to copy, study and to change. Students and computer programmers grabbed it.

Soon, commercial vendors moved in. Linux itself was, and is free. What the vendors did was to compile up various software and gather them in a distributable format, more like the other operating systems with which people were more familiar. Red Hat , Caldera, and some other companies gained substantial amount of response from the users worldwide. While these were commercial ventures, dedicated computer programmers created their very own volunteer-based distribution, the famed Debian. With the new Graphical User Interfaces (like X-window System, KDE, GNOME)the Linux distributions became very popular.

Meanwhile, there were amazing things happening with Linux. Besides the PC, Linux was ported to many different platforms. Linux was tweaked to run 3Com's handheld PalmPilot computer. Clustering technology enabled large number of Linux machines to be combined into a single computing entity, a parallel computer. In April 1996, researchers at Los Alamos National Laboratory used Linux to run 68 PCs as a single parallel processing machine to simulate atomic shock waves. But unlike other Supercomputers costing a fortune, it was rather cheap. The do-it-yourself supercomputer cost only $152,000, including labor (connecting the 68 PCs with cables)-about one tenth the price of a comparable commercial machine. It reached a peak speed of 19 billion calculations per second, making it the 315th most powerful supercomputer in the world. And it was a robust one too. Three months later it still didn't have to be rebooted.

A Beaming Linus Today

The best thing about Linux today is the fanatic following it commands. Whenever a new piece of hardware is out, Linux kernel is tweaked to take advantage of it. For example, within weeks after the introduction of Intel Xeon® Microprocessor, Linux kernel was tweaked and was ready for it. It has also been adapted for use in Alpha, Mac, PowerPC, and even for palmtops, a feat which is hardly matched by any other operating system. And it continues its journey into the new millennium, with the same enthusiasm that started one fine day back in 1991.

Patricia Miranda Torvalds
Linus in 2002

As for Linus, he remains a simple man. Unlike Bill Gates, he is not a billionaire. Having completed studies, he moved to USA and landed a job at Transmeta Corporation. After conducting a top-secret research and development project, Transmeta launched the CrusoeĆ¢„¢ processor. Linus was an active member of the research team. Recently married to Tove, he is the proud father of a girl, Patricia Miranda Torvalds. But he remains as the world's most favorite and most famous programmer to this date. Revered by Computer communities worldwide, Linus is by far the most popular programmer on this planet.

d. After a Decade: Linux Today

Proving all the warning and prophecies of the skeptics wrong, Linux has completed a decade of development. Today, Linux is one of the fastest growing operating systems in the history. From a few dedicated fanatics in 1991-92 to millions of general users at present, it is certainly a remarkable journey. The big businesses have 'discovered' Linux, and have poured millions of dollars into the development effort, denouncing the anti-business myth of the open-source movement. IBM corp. once considered the archenemy of open-source hacker community, has come forward with a huge fund for development of open source Linux based solutions. But what's really amazing is the continuously increasing band of developers spread throughout the world who work with a fervent zeal to improve upon the features of Linux. The development effort is not, as many closed-sourced advocates accuse, totally engulfed with chaos. A well designed development model supervised by some maintainers is adopted. Along with this, there are thousands of developers working to port various applications to Linux.

Commercial enterprises are no longer wary of Linux. With a large number of vendors providing support for Linux based products, it is no longer a 'do-at-your-own-risk' thing to use Linux at the office. As for reliability, Linux certainly proved it during the nasty attacks of the CIH virus in 1999 and the love bug a year later, during which Linux based machines proved to be immune to the damages caused by these otherwise quite simple computer viruses. Linux startups like Red Hat received a cordial response as they went public. And even after the dot-com bust of the recent years, these companies continue to thrive and grow. With this added confidence, many large and small businesses have adopted Linux based servers and workstations as an integral part of their offices.

Rise of the Desktop Linux

What is the biggest complain against Linux? Perhaps in the past, it was the text based interface which scared off many people from using it. 'Text mode gives total control', some dedicated hackers and heavy users may explain. But for the millions of ordinary people, it also means a lot of effort towards learning the system. The existing X-Window system and the window managers were not up to the general computer users' expectation. Exactly this argument had always been put forward by dedicated followers of the Windows(TM) camp. But things began to change in the last couple of years. The advent of professional looking desktop environments like KDE( K Desktop Environment) and GNOME completed the picture. The recent versions of these desktop environment have changed the general perception about the 'user friendliness' of Linux to a great extent. Though hard-core users grumble about the loss of purity of the hacker-culture, this great change in the mindset of the common users has increased the popularity of Linux.

Today, almost distributions of Linux include user-friendly GUIs. Installation has also become easier. Gone are the days when users would need detailed expertise in computer hardware to install Linux ... distributions like Ubuntu, Debian, Suse, Knoppix, and Red Hat's Fedora Core can be installed by even novice users. Most distributions are also available in Live CD format, which the users can just put in their CD drives and boot without installing it to the hard drive, making Linux available to the newbies.

Linux in the Developing World

Perhaps the greatest change is the spread of Linux to the developing world. In the days before Linux, developing countries were way behind in the field of computing. The cost of hardware fell down, but the cost of software was a huge burden to the cash-strapped computer enthusiasts of the Third World countries. In desperation, people resorted to piracy of almost all sorts of software products. This resulted in widespread piracy, amounting to billions of dollars. But then again, the pricetag of most of the commercial products were far beyond the reaches of the people in developing countries. For example, a typical operating system product costs at least US $100 or more. But in countries with per capita incomes of about US$200-300, is a huge amount.

The rise of Linux and other related open source product has changed it all. Since Linux can be scaled to run in almost computer with very few resources, it has become a suitable alternative for low budget computer users. Old, ancient 486/Pentium 1 computers that has become a part of history in the developed world are still used in developing countries. And Linux has enabled to unleash the full potential of these computers. The use of open source software has also proliferated, since the price of software is a big question. In countries of Asia, Africa and Latin America, Linux has appeared as a way out for the masses of computer enthusiasts. And a testament to the true global nature of Linux, local customizations were made in obscure parts of the world. The Linux documentation now includes documents written in almost all the major languages ... and also many minor ones, for example, Vietnamese.

From Desktop to SuperComputing

When Linux was first envisaged by Linus Torvalds, it was just another hackers hobby. But from the humble Intel 386 machine of Linus that ran the first kernel, Linux has come a long way. Its most notable use now is in the field of massively parallel supercomputing clusters.

In August 2001, BBC reported that the US Government was planning to build what would be a mega computer, capable of performing over 13 trillion calculations per second (13.6 TeraFLOPS). The project, called Teragrid would consist of a connected network of 4 US supercomputing centers. The four labs that are collaborating to create the Teragrid are: National Center for Supercomputing Applications at the University of Illinois(NCSA), San Diego Supercomputer Center (SDSC) at the University of California Argonne National Laboratory in Chicago; California Institute of Technology in Pasadena. At each of these centers, there would be a supercomputer. In total, there would be more than 3000 processors running in parallel to create the Tetragrid.

By 2005, the use of Linux became more prevalent in Supercomputing. The 2005 Top500 list of Supercomputers shows that 4 of the top 5 fastest supercomputers use Linux as their operating system.

The Journey Continues

The journey of Linux from a hacking project to globalization has been more like an evolutionary experience. The GNU Project, started in the early 1980's by Richard Stallman, laid the foundation for the development of open source software. Prof. Andrew Tanenbaum's Personal Computer operating system Minix brought the study of operating systems from a theoretical basis to a practical one. And finally, Linus Torvald's endless enthusiasm for perfection gave birth to Linux. Throughout the last couple of years, hundreds of thousands of people forming global community nurtured it and brought it to its glorious place in the annals of the computer revolution. Today Linux is not just another student's hacking project, it is a worldwide phenomenon bringing together huge companies like IBM and the countless millions of people throughout the world in the spirit of the open source software movement. In the history of computing, it will forever remain as one of the most amazing endeavors of human achievement.

e. Tux the penguin: Linux's Dear Logo

The logo of Linux is a penguin. Unlike other commercial products of computer operating systems, Linux doesn't have a formidable serious looking symbol. Rather Tux, as the penguin is lovingly called, symbolizes the carefree attitude of the total movement. This cute logo has a very interesting history. As put forward by Linus, initially no logo was selected for Linux. Once Linus went to the southern hemisphere on a vacation. There he encountered a penguin, not unlike the current logo of Linux. As he tried to pat it, the penguin bit his hand. This amusing incident led to the selection of a penguin as the logo of Linux sometime later.

f. Some Linux Cookies

Here are some famous words by Linus himself.

Dijkstra probably hates me
(Linus Torvalds, in kernel/sched.c)

"How should I know if it works? That's what beta testers are for. I only
coded it."
(Attributed to Linus Torvalds, somewhere in a posting)

"I'm an idiot.. At least this one [bug] took about 5 minutes to find.."
(Linus Torvalds in response to a bug report.)

"If you want to travel around the world and be invited to speak at a lot
of different places, just write a Unix operating system."
(By Linus Torvalds)

> > Other than the fact Linux has a cool name, could someone explain why I
> > should use Linux over BSD?

> No. That's it. The cool name, that is. We worked very hard on
> creating a name that would appeal to the majority of people, and it
> certainly paid off: thousands of people are using linux just to be able
> to say "OS/2? Hah. I've got Linux. What a cool name". 386BSD made the
> mistake of putting a lot of numbers and weird abbreviations into the
> name, and is scaring away a lot of people just because it sounds too
> technical.
(Linus Torvalds' follow-up to a question about Linux)

> The day people think linux would be better served by somebody else (FSF
> being the natural alternative), I'll "abdicate". I don't think that
> it's something people have to worry about right now - I don't see it
> happening in the near future. I enjoy doing linux, even though it does
> mean some work, and I haven't gotten any complaints (some almost timid
> reminders about a patch I have forgotten or ignored, but nothing
> negative so far).

> Don't take the above to mean that I'll stop the day somebody complains:
> I'm thick-skinned (Lasu, who is reading this over my shoulder commented
> that "thickheaded is closer to the truth") enough to take some abuse.
> If I weren't, I'd have stopped developing linux the day ast ridiculed me
> on c.o.minix. What I mean is just that while linux has been my baby so
> far, I don't want to stand in the way if people want to make something
> better of it (*).

> (*) Hey, maybe I could apply for a saint-hood from the Pope. Does
> somebody know what his email-address is? I'm so nice it makes you puke.
(Taken from Linus's reply to someone worried about the future of Linux)

`When you say "I wrote a program that crashed Windows", people just stare at
you blankly and say "Hey, I got those with the system, *for free*".'
(By Linus Torvalds)

G. Timeline of Linux History

Date Event
January 1984 Richard Stallman quits his job at MIT and starts working on the GNU Project.
Month unknown Free Software Foundation, an organization for creating and promoting free software, is founded by Richard Stallman.
March 1985 The GNU manifesto, a statement by Richard Stallman advocating the cause of free software movement, is published in the March 1985 issue of Dr. Dobb's Journal
August 25 1991 Linus conceives the idea of Linux and announces the project in a Usenet Post
September 1991 Version 0.01 is released on the Net
January 1992 First Linux Newsgroup: alt.os.linux founded in the UseNet
April 1992 Ari Lemmke starts the popular Linux newsgroup comp.os.linux in the UseNet
November 1992 Adam Richter announces the release of the first Linux Distribution from his company: Yggdrasil
June 1993 Slackware, the famous Linux distribution is released by Peter Volkerding
August 1993 Matt Welsh releases Linux Installation and getting started: version 1
March 1994 Linux kernel version 1.0 is released

Monday, 17 September 2007

How to break grub password

To break the GRUB start-up password, follow the steps given below:

1. Boot the system with the first Linux CD. At the boot prompt, type linux rescue to switch to rescue mode. In rescue mode you will be asked if similar steps should be followed, which need to be followed in the installation. Once you get the # prompt, type the following command:

# chmod /mnt/sysImage

2. Edit the grub.conf file and remove the passwd line from the file. Save the file and exit.

3. Once your machine reboots, you will be able to start your Linux OS in the usual manner.

How to compile a kernel

kernel version 2.4.30.tar.gz

Go to old kernel directory .Find the .config file and copy it to the new decompressed Kernel directory .If .config file is not exist then create .

[root@ns1 linux-2.4.18]#make dep

[root@ns1 linux-2.4.18]#change few option .then save

[root@ns1 linux-2.4.18]#ls –alh | grep .config

[root@ns1 /usr/src]#tar –zxvf linux-2.4.30.tar.gz

[root@ns1 src]#cd /usr/src/linux-2.4.30

[root@ns1 linux-2.4.30]#cp /usr/src/linux-2.4.18/.config /usr/src/linux-2.4.30

[root@ns1 linux-2.4.30]#make dep

[root@ns1 linux-2.4.30]#make modules

[root@ns1 linux-2.4.30]#make modules_install

[root@ns1 linux-2.4.30]#make bzImage

[root@ns1 linux-2.4.30]#cp arch/i386/boot/bzImage /boot/vmlinuz-2.4.30

[root@ns1 linux-2.4.30]#cp /boot/

[root@ns1 linux-2.4.30]# mkinitrd /boot/initrd-2.4.30.img 2.4.30

[root@ns1 linux-2.4.30]#vi /etc/grub.conf

#root (hd0,0)

#kernel /vmlinuz-version ro root=/dev/hda5

#initrd /initrd-version.img





title Red Hat Linux (2.4.30)

root (hd0,0)

kernel /vmlinuz-2.4.30 ro root=LABEL=/ vga=0x0309

initrd /initrd-2.4.30.img

title Red Hat Linux (2.4.18)

root (hd0,0)

kernel /vmlinuz-2.4.18 ro root=LABEL=/ vga=0x0309

initrd /initrd-2.4.18.img

== Kernel==2.6==

make menuconfig
make modules_install
make install

Install Squid Proxy Server


Check for the user Squid:

1) #finger squid

If not then use the command

2) #useradd –d /usr/local/squid squid

Download the tar package from

3) wget

Extract & Install the tar package

4) #tar –zxvf squid-X.X.X.tar.gz

5) #/configure

6) #make

7) #make install

Now installation is complete. Configure your Squid server:

8) # vi /usr/local/squid/etc/squid.conf

http_port 8080

cache_mem 40 MB

cache_swap_low 80

cache_swap_high 85

maximum_object_size 8096 KB

minimum_object_size 0 KB

cache_dir ufs /usr/local/squid/cache 1024 16 128


cache_dir diskd /cache/cache1 9500 35 256

cache_dir diskd /cache/cache2 9500 35 256

cache_access_log /usr/local/squid/var/logs/access.log

cache_log /usr/local/squid/var/logs/cache.log

Configure your Access list to which you want to give permission to use your


acl all src

acl locallan src ##Your client Address & Subnet Mask

http_access allow locallan

http_access deny all

Give the Permission to the user:

cache_effective_user squid

Configure your Host name:


For creating cache directory

#/usr/local/squid/sbin/squid –z

#chown –R squid.squid /usr/local/squid/

#chmod 777 /usr/local/squid/

To run squid


Now configure a client with the IP which you use in your ACL part with port 8080. Because we use the port 8080. And test your proxy server with the following command:

#tail -f /usr/local/squid/var/logs/access.log

Now you browse a site from your configured client PC. If your server is working well you browse successfully and see your access log in your server. You also check your squid process by the following command:

#pgrep squid

Hope your server is working well. If you face any problem please mail to me.