Multiple servers Hosting
Posted on Sep 5, 2008 10:00:31 PM
If you have decided that you need to add few more server to your setup. It can be done easily by following the exapmles given below:-
1)You must add a new database server. Taking away the load of database processing from the single server is one of the most common steps most growing sites will do.
2)Add a new server for load balancing a web server. To provide increase processing power for dynamic web applications and also add a redundancy level to the setup. This move is very common for dynamic applications powered by PHP for example.
3)Add a new server to serve static content. Another common start is to separate static content from dynamic content. A separate server with a quick stripped web daemon can serve much faster and much more than a server that is handling also dynamic pages, etc.
4)These are just a few examples on how you can start your multiple-server setup. You are able to implement those changes in your application and configure the technical solution.
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.
Who developed the Linux?
Posted on Sep 2, 2008 01:14:04 AM
In 1991, Linus Torvalds studding UNIX at the University, where he used special educational experimental purpose operating system called Minix (small version of UNIX and used in Academic environment). However, Minix had its own limitations. Linus felt he could do better than the Minix. Therefore, he developed his own version of Minix, known as Linux. Linux is Open Source From the start of the day.
What is Linux Kernel?
Posted on Sep 2, 2008 01:11:44 AM
Kernel is heart of Linux operating system. It manages resource of Linux. Resources include facilities available in Linux:
* File management
* Multitasking
* Memory management
* I/O management
* Process management
* Device management
* Networking support including IPv4 and IPv6
* Advanced features such as virtual memory, shared libraries, demand loading, shared copy-on-write executables etc
Kernel decides who will use these resources and for how long and when. It runs your programs or set up to execute binary files.
The kernel acts as an intermediary between the computer hardware and various programs/application/shell.
What is Linux Shell?
Posted on Sep 2, 2008 01:10:23 AM
Computer understands the language of zeros and ones known as binary language. In early days of computing, instruction provided using binary language, which is difficult for all of us, to read and write. Therefore, in operating system there is special program called shell. Shell accepts your instruction or commands in english language and if it is a valid command, kernel will process your request.
Shell is a user program or it is environment provided for user interaction. It a command language interpreter that executes commands read from the standard input device (keyboard) or from a file.
To find all available shells in your system type following command:
$ cat /etc/shells
Note that each shell does the same job, but each understand different command syntax and provides different built-in functions.
Under MS-DOS, shell name is COMMAND.COM which is also used for same purpose, but it is not as powerful as our Linux Shells are!
Command line interface (CLI)
Shell provides an interface to the Linux where you can type or enter commands using the keyboard it know as command line interface (CLI).
To find out your current shell type following command:
$ echo $SHELL
$ ps $$
How to use Linux Shell?
Posted on Sep 2, 2008 01:08:37 AM
To use shell you have to simply type Linux and shell commands. A command is a computer program to perform a specific task. An example of commands:
* ls
* clear
* cal
* date
* vi
You start to use your shell as soon as you log in into your Linux system.
Define::Shell Scripting
Posted on Sep 2, 2008 01:06:40 AM
Normally shells are interactive. It accept command from you and execute them. However, if you store (sequence of ‘n’ number of commands) sequence of commands to text file and tell the shell to execute text file instead of entering the commands, known as a shell program or shell script.
It is defined as “Shell script is a series of command(s) stored in plain text file. Shell script is just like batch file is MS-DOS but have more power than the MS-DOS batch file”.
Each shell script consists of the following:-
* Shell commands such as if..else, do..while
* Linux text processing utilities such as grep, awk, cut
* Linux binary commands such as w, who, free etc
What are the advantages of Shell script?
1) It is the shell that lets you run different commands without having to type the full pathname to them even when they do not exists in current directory
2) The shell expands wildcard characters, thus saving you laborious typing
3) It gives you ability to run previously run commands without having to type the full command again
4) It is the shell that does input, output and error redirection
Why shell scripting?
Posted on Sep 2, 2008 01:05:24 AM
1) Shell script can take input from user or file and output them on screen
2) Whenever you find yourself doing same task again and again you should use scripting i.e. repetitive task automation
3) Time saving
4) Creating your own power tools/utilities
5) Customizing administrative task
6) Since scripts are well tested, chances of errors reduced while configuring services or system administration task such as adding new users
7) Practical examples where shell scripting actively used:
o Monitoring Linux system
o Data backup and creating snapshots
o Dumping Oracle or MySQL database for backup
o Creating email based alert system
o Find out process which eats up more system resources
o Find out available and free memory
o Find out all logged in users and what they are doing
o Find out if all necessary network services are running or not. For example if web server failed send an alert to system administrator via a pager or an email
o Find out all failed login attempt, if login attempt are continue repeatedly from same network IP automatically block all those IPs accessing our network/service via firewall
o Find out process which eats up more system resources
o User administration as per your own security policies
o Find out information of local or remote servers
o Configure server such as BIND (DNS server) to add zone entries
Shell scripting is fun, I enjoy it because not every handy little functionality available in built into command or program library. It is useful to create nice (perhaps ugly) things in shell scripting. Here are few script example I use everyday:
* Find out todays weather (useful when you are busy in chat room)
* Find out what’s that site running (just like netcraft)
* Download RSS feed and display them as long as you login or email them
* Find out name of MP3 file you are playing (useful when you are busy in chat room)
* Monitor your domain expiry day