Archive for the ‘Linux Server Hosting’ Category

Define Server

Posted on Sep 2, 2008 01:18:50 AM

Every well-connected network needs a server.

How to find a right server for us?

Buying a network fileserver can be as simple as picking up a phone or logging onto a Web site. Placing the order is by far the simplest part of the process, but before you begin you will need some idea of what kind of system you need and what it is going to be used for; if not, you’ll end up with a server that’s either under-powered or has excessive functionality for the kind of network and applications you want to run, and the numbers of users you want to support.

Where to start?

No matter how big the system you’re planning to buy, it’s important always to specify customised server hardware. On the face of it, smaller servers can appear much the same as desktop PCs, equipped with the same processor, memory and disks, but PCs rarely have the reliability and management features required of servers, and any cost savings obtained by opting for the former will be minimal.

It’s also worth talking to vendors about your needs; even when buying direct you don’t have to rely solely on your own knowledge. Most companies are more than willing to offer advice, with the best able to give a full analysis, design and installation service that can go a lot further than just the network fileserver. It’s unlikely to be free, of course, but if you’re new to networking, or are unsure about the technologies involved, it’s a service that’s well worth paying for.

How to setup Mail server fedora?

Posted on Sep 2, 2008 01:16:03 AM

1) Go for Postfix it is easy to use and configure

2) Go for SpamAssassin, a powerful open source spam filter http://spamassassin.apache.org/

3) Go for clamav http://www.clamav.net/ virus scanner, you can also use commercial anti virus for your mail server such as McAfee or others

4) You also need to setup IMAP and POP3 server such as dovecot http://www.dovecot.org/ or Cyrus IMAP http://asg.web.cmu.edu/cyrus/imapd/

5) Postfix Howtos and FAQs http://www.postfix.org/docs.html

What is Linux?

Posted on Sep 2, 2008 01:15:06 AM

Linux is a free open-source operating system based on Unix. Linus Torvalds originally created Linux with the assistance of developers from around the sphere.

Linux is a kernel that provides access to the computer hardware and control access to resources. Kernel decides who will use resource, for how long and when. You can download Linux kernel from their official web site.

However, Linux kernel itself has no use until and unless you get all the applications such as text editors, email clients, browsers, office application etc. Therefore, someone comes with idea of Linux distribution. A typical Linux distribution includes:

* Linux kernel
* GNU application utilities such as text editors, browsers
* GUI (X windows)
* Office application software
* Software development tools and compilers
* Moreover, over thousands of ready to use application software packages
* Linux Installation programs/scripts
* Linux post installation management tools for day today life work such as adding users, installing application etc

Corporate and small business need support while using Linux, so companies such as Red Hat, Novell, provides Linux tech-support and sell it as product. Nevertheless, community driven Linux distribution do exists such as Debian, Gentoo and they are entirely free. To be frank there are over 200+ Linux distribution.

Why Process are required in Linux

Posted on Sep 2, 2008 12:10:50 AM

As You know Linux is multi-user, multitasking operating system. You can run more than 2 process at the same time. For example if you want to find the number of files you have on your system you may give command like:

$ ls / -R | wc -l
This command will take lot of time to search all files on your system. So you can run such command in Background or simultaneously by giving command like

$ ls / -R | wc -l &
The ampersand (&) at the end of command tells shells start process (ls / -R | wc -l) and run it in background takes next command immediately.

Process & PID defined as:
“An instance of running command is called process and the number printed by shell is called process-id (PID), this PID can be use to refer specific running

How to de-bug the shell script?

Posted on Sep 2, 2008 12:09:51 AM

While programming shell sometimes you need to find the errors (bugs) in shell script and correct the errors (remove errors - debug). For this purpose you can use -v and -x option with sh or bash command to debug the shell script. General syntax is as follows:
Syntax:
sh   option   { shell-script-name }
OR
bash   option   { shell-script-name }
Option can be
-v Print shell input lines as they are read.
-x After expanding each simple-command, bash displays the expanded value of PS4 system variable, followed by the command and its expanded arguments.

Example:
$ cat > dsh1.sh
#
# Script to show debug of shell
#
tot=`expr $1 + $2`
echo $tot

Press ctrl + d to save, and run it as
$ chmod 755 dsh1.sh
$ ./dsh1.sh 4 5
9
$ sh -x dsh1.sh 4 5
#
# Script to show debug of shell
#
tot=`expr $1 + $2`
expr $1 + $2
++ expr 4 + 5
+ tot=9
echo $tot
+ echo 9
9

See the above output, -x shows the exact values of variables (or statements are shown on screen with values).

$ sh -v dsh1.sh 4 5

Use -v option to debug complex shell script.

AWK::Arithmetic

Posted on Sep 2, 2008 12:07:58 AM

You can easily, do the arithmetic with awk as follows:-
$ cat > math
{
print $1 ” + ” $2 ” = ” $1 + $2
print $1 ” - ” $2 ” = ” $1 - $2
print $1 ” / ” $2 ” = ” $1 / $2
print $1 ” x ” $2 ” = ” $1 * $2
print $1 ” mod ” $2 ” = ” $1 % $2
}

Run the awk program as follows:

$ awk -f math
20 3
20 + 3 = 23
20 - 3 = 17
20 / 3 = 6.66667
20 x 3 = 60
20 mod 3 = 2
(Press CTRL + D to terminate)

Note:In above program print $1 ” + ” $2 ” = ” $1 + $2, statement is used for addition purpose. Here $1 + $2, means add (+) first field with second field. Same way you can do - (subtraction ), * (Multiplication), / (Division), % (modular use to find remainder of division operation).