Technofunction

This post is the second half of my earlier post of installing and configuring Vmware to install CentOS/RedHat Linux . This post is also relevant if you need basic configuration. By basic we means using 3 options to create default partition and not using the custom partition options during installation. So considering that either you have already installed and configured Vmware to run Linux or You are installing Linux on a system. We begin with the installation.

Once you have successfully installed vmware you would see your virtual machine in the left column as shown below in the screenshot with virtual machine name is Virtual Machine Linux OS. Select it and turn it on by selecting power on on right side column.

Next select the console tab.

You will see the black console screen. This might give you an error as it cant find the plugin needed by Vmware. Simply click on the Install Plug-in option so that it install the plugin for you. Once initiated it will install the plug-in as you can see in the screen-shot below

Next you will see the Console window.

Note:- See that you have already inserted the CentOS/RedHat Linux Dvd/Cd in the Dvd/Cd drive to start the installation once your virtual machine is started.

Simply click anywhere to start the virtual machine and start with CentOS/RedHat installation.

Click Next to start the installation.

Select your desired Language here. In Our Case its English select it and click next

Select the Keyboard type that matches yours. In our case is U.S. English select it and click Next

Now this screen is important as it is asking you to select the partition in here. You have 3 default choices i.e Remove all partition and create defaults this will remove all the partitions on your drive and create Linux partition. Second is that it will create the partition on the free space on your drive remember you must have free space on your drive to use this option. Third one is to remove all previous Linux partitions and create new. And fourth is create a custom layout for your partition here you yourself specify the size for each partition(/, /boot, /home etc).

Since we have created a new virtual machine here so we will go with remove all partition and create default. Since there are no data on this virtual machine previously. With default partition Linux uses LVM(Logic Volume Manager) to manage your hard disk and partitions. Select the review and modify Layout option at the end and click next.

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The Linux is all about hands-on. You need to practice as much as possible in order to do the things correctly. Although there are utilities in Linux which helps you to make your work easier like Bash shell(Bourne Again Shell) which is the default shell allotted to a user once he login to the Linux server. It is more suitable for system administrators and moreover if you simply wanna navigate and use Linux. The unique feature of bash is the after typing a partial command, if you press tab it will complete it or otherwise show you the possible commands which becomes very useful in finding paths and file names. But to do all this you first need to install a Linux so that you can start exploring and practicing on it.

There are two types of installation of Linux:-

1. Default: In this type of installation all the partitions are created by Linux itself using default settings and it uses LVM(Logical volume manager) to manage the partitions.
2. Custom: This one is the best and you should use this as it helps to troubleshoot easily and moreover you can make better utilization of your hard drive by allotting desired space to each partition manually. But than again it requires good understanding and is recommended for advanced users more to the system administrators.

In this post we will be going through the default installations i.e. we will be using default settings for partitions in Linux. Apart from that we will be using Vmware to install Linux over windows so that Linux can be run on Windows under Vmware.

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Windows developer integrated the GUI(Graphical user interface) with the core system. Which simply means one simply doesn’t exist without the other. The advantage of this lies in the consistency of the appearance of the system. However, Microsoft does not impose rules as strict with Apple’s w.r.t appearance of applications.

Linux has kept the two elements—i.e. user interface and operating system—separate. The X Window System interface responsible for (GUI) in Linux is run as a user-level application, which makes it more stable. If the GUI (which is very complex for both Windows and Linux) fails, Linux’s core does not go down with it unlike that of the windows. The X Window System also differs from the windows 2000 GUI in that it isn’t a complete user interface in itself but rather it only defines how basic objects should be drawn and manipulated on the screen.

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This is a very basic question for a new user migrating from windows and giving a try to Linux.  There are enormous advantages of Linux over windows so I will be considering very common advantages and that to in a much summarized points:-

• While Linux is multi-user operating system windows is only a single user operating system. So in Linux more than one user can log on to a server at the same time and can write and modify files. While windows is meant for only end-users working on their desktops.

• Linux is free for its user and believes in open source development carried out by thousands of volunteers around the world. On the other hand you need to pay for windows and its product. Companies like Red Hat charge you only for support that they provide you.

• Linux is more about freedom in the way that you can alter its code to fulfill your own needs while you are not provided with same functionality in windows.

• Linux is customizable while windows are 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.

• Microsoft allows a single copy of its Windows to be used on only one computer. This has been started with Windows XP initially and continued even today with windows7, they use Windows activation to enforce this rule. In contrast, once you have purchased Linux, you can run it on any number of computers for no additional charge.

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Every computer in the world has a system administrator. By definition, the Linux system administrator is the person who has “root” access, which is to say the one who is the system’s “super user” (or root user). A standard Linux user has limitations. But the “root” user has unfettered access to everything — all user accounts, their home directories, and the files therein; all system configurations; and all files on the system. While a administrator has got so much privilege in the Linux system and hence comes the responsibilities and duties. Some of the common duties of Linux system administrators are:-

1. Installing and Configuring Servers:-

Red Hat Linux is shipped with a support for quite a number of servers. Essentially servers are off unless they are manually enabled and configured. The duty of configuring servers and looking after them ensuring that they properly function falls to the system administrator. Administrator need to know what servers are needed within an organization and how to employ them.

With Linux the word server has a much broader meaning, the standard Red Hat Linux graphical user interface (GUI) requires a graphical layer called XFree86. XFree86 is a server. Similarly, printing in Linux takes place after you have configured a print server.  And whenever a server is connected to other machines on network outside ones physical control (remotely), there are security implications — As a system administrator you want users to have easy access to the things they need, but you don’t want to open up the system you’re administering to the whole wide world.

2. Installing and Configuring Application Software

As you know Linux is a multi-user operating system i.e. more than one user can log onto to server at same time and work at a same time. These users have their account in the Linux. Each user has a home directory and has permissions to use applications and program which they are allowed to access by the root or superuser.

Although Individual users are allowed to install some applications in their home directories —these applications are not available to other users. If an application is to be used by more than one user like forms used in your enterprise, it needs to be installed higher up in the Linux file hierarchy, which is a job of the system administrator only. (The administrator can even decide which users may use which applications by creating a “group” for that application and assigning each individual user into that group.)

3. Creating and Maintaining User Accounts:-

Anyone logging on to a Linux server needs a user account and these accounts are created and managed by Linux administrator. There are decisions that an administrator has to make like he may allow users to select their own passwords, which would be simple and easier for them to remember, but which probably would be easier for an external factor to crack. On the other hand he may assign them passwords, which are more secure in theory but it increases the chances that users will write them down on a conveniently located scrap of paper — a risk if many people have access to the area where the machine(s) is located. You can configure Red Hat Linux so that users must change their passwords periodically (like every week, month etc).

Also you may want to keep an account of the user who have left the company because it might contain some useful data, but you surely don’t want them to have access to companies data.

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In my previous post on Overview of Linux I already discussed some distinct advantages of using Linux let’s see some more advantages of Linux OS.

With the stagnant budgets of I.T Companies, a number of them have shifted to Linux system already. Some companies to name which are using Linux to power there server are Goldman Sachs, Merrill Lynch, Morgan Stanley, Amazon, Google, IBM, Hewlett-Packward and various other corporate and small companies. Infact according to a survey, Linux/Unix share has increased to 60%-70% in corporate world which includes hosting, software’s, manufacturer, production and other companies. The Advantages of using Linux are as follows:-

1. Linux is Inexpensive:-

Since Linux is an open source project and freely distributed so you can download it absolutely free and even update it as well.

2. Linux is Reliable:-

Linux kernel and software’s are very stable and also as they kept CUI and GUI separate there is an increase in the reliability. And by using a single user mode you can actually troubleshoot any problem which is unlikely to happen if you have good system administrators. You can rely on Linux to take care of your servers and data.

3. Linux is Secure:-

Linux is very much secure since it involves different levels of security for all users in the form of permissions which can be assigned to a directory, file etc. Also by default Linux kernel doesn’t execute a program until it is told to do so by the user. Also you don’t need any third party program like antivirus or firewall a number of tools are shipped along with Linux to check intrusion and prevent network attacks. Also the Linux ports are closed by default so it provides safety against advanced hacking practices like port knocking etc.

4. Free or Limited cost applications:-

With Linux OS you get a lot of software’s in the form of packages on Linux cds/DvD itself and even download many more which doesn’t cost you money or may cost you a fraction of it for their licensing unlike in other OS where you need to spend hundreds of dollar for software’s which only run on a single server.

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Tux - Linux Mascot

Linux is generally regarded as an operating system but technically Linux is not a complete operating system in itself. Since Linux is basically a name of the kernel which was developed by LINUS TORVALDS, who was a computer science student back in the year 1991 and now considered as one of the most influential person in the field of Information technology.

It is important to note that an operating system consist of two parts i.e. system software and an application software. Since kernel is system software which is Available for free on the Linus Torvalds site “kernel.org” and is distributed freely under the GPL (GENERAL PUBLIC LICENSE).

But back in the 1984, the GNU Project (GENERALLY NOT UNIX) project was started which is also popularly known as free software foundation. The word “free” used here is not regarded in terms of money but infact it has been derived from the word “freedom”. The main idea behind it was to develop software with the help of the volunteers around the world and provide the software as well as the code along with it which is even followed today in the form of the source code available along with each Linux distribution. The code is supplied with a view that if user wants to add some additional functionality to the software which may be helpful for him to make is work easier, he can do it. Unlike the other paid software shipped which doesn’t allow you to edit or make changes to them which means if you buy a software for 200$ or so and not able to fulfill your need some time in future than either you need to wait for the next release and buy it again or find some other way out. So in order to deal with this problem and also give a boost to software development free open source projects were created

Linux is the best example of an open source project that has been built by thousands of volunteers around the world starting from the scratch. Because the Linux is developed by users around the world it keeps the user needs intact so that you won’t face any problem in your work. Also as it is freely available under GNU and GPL License you can download it, update it and even sell it by adding some more software’s with it. But you may not sell it with the distributions name now and use your own suitable name. More about it can be found in the License details of GPL and GNU.

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