What is the linux? Linux (often pronounced LIH-nuhks with a short "i") is a Unix-like operating system that was designed to provide personal computer users a free or very low-cost operating system comparable to traditional and usually more expensive Unix systems. Linux has a reputation as a very efficient and fast-performing system. Linux's kernel (the central part of the operating system) was developed by Linus Torvalds at the University of Helsinki in Finland. To complete the operating system, Torvalds and other team members made use of system components developed by members of the Free Software Foundation for the GNU Project. Linux is :- Multiusers Multitsking Client/Srver Platform Open source Nature Free Software Program Facility . Types off linux:- RedHat Linux CentOS Fedora Ubuntu

Linux fedora 10 Installation :- Hardware Requirements :- Processor:- Intel Atom 230, Atom 330, Core 2 Duo, Centrino Core 2 Duo, and Xeon; AMD Athlon64/x2, Sempron64/x2, Duron64 Ram:- At least 500 mb ram hard disk :- 50 gb

Installing Fedora 10 Step

Linux fedora Installation minium Requirent Minimum partion two:- /root /swap Maximum Partion four:- /root (35000 mb at list) /home (512 mb ) /boot (100 mb) /swap (double size gor ram) (exam:- Your ram is 521 mb, so swap size is 1024 mb ){swap is logical file system} Note:- Linux use the ext2. Ext3. Ext4 file system Fedora 10, also known as Cambridge, was released on November 25th, 2008, and it brings GNOME 2.24 and KDE 4.1, faster boot experience with Plymouth, better printing, better webcam support, improved wireless network connection sharing, better software maintenance and update (powered by PackageKit and RPM 4.6), and virtualization storage. Plus, it adds a new security tool for IDS (Intrusion Detection System) called SecTool.

The following tutorial will teach you how to install the DVD edition of the Fedora 10 operating system on your PC. Why the DVD edition? Because we believe it offers most of the applications you'll need. For those of you that don't have a fast Internet connection, we recommend using one of the Live GNOME or KDE4 editions. However, this guide will make things very simple for you, but if you get stuck somewhere in the middle of the installation and you need help, do not hesitate to use our commenting system at the end of the article.

At this stage, we simply suggest you press Enter, and wait for the system to load...

Select the "Skip" option when you're asked if you want to check the media before installation, and press "Enter"...

Anaconda (the Fedora installer) will load and you'll see the welcome screen. Click "Next"...

Choose your language...

Choose your keyboard layout...

Type a name for the computer. It can be anything you want...

Select your location (country/city)...

Enter the root (System Administrator) password. The longer, the better (WRITE IT SOMEWHERE)...

Here comes the partitioning part! If you have an empty hard drive, all you have to do is click "Next," but make sure the "Remove all partitions on selected drives and create default layout" option is selected. If you don't have an empty hard drive and you still want to install Fedora 10 on

your machine, then make sure you select the "Use free space on the selected drives and create default layout" option (10 GB minimum of free space is required). Click "Next"...

We also recommend to select the "Encrypt system" option. Enter a password (the longer, the better) for the encrypted partition...

Click the "Write changes to disk" button when asked...

The hard drive will be formatted and the partitions will be created...

Now, you can select the desired packages...

Hit the "Next" button and everything will be done automatically from now on, just sit back and watch how the packages are copied to your hard drive, or you can read the latest news while enjoying a cup of coffee. The installation process will take about 8-10 minutes (depending on your computer specs and the selected packages).

When the installation is over, you will get a "Congratulations, the installation is complete" screen. Click the "Reboot" button and your computer will automatically restart...

Remove the DVD from your optical drive. Your brand new Fedora 10 operating system will boot for the first time...

If you've chosen to encrypt your partition, then you'll be prompted for the passphrase...

The system will continue to boot and in a few seconds you will see the First Boot Configuration Wizard. Click "Forward" on the Welcome screen...

Click "Forward" on the License screen...

Create a regular user for the system...

Set the date and time...

Send your hardware profile to the Fedora Project (optional)...

Click "Finish" and you will see the login screen. Enter the password for the regular user you've just created...

That's it! Enjoy the ultimate and breathtaking Fedora 10 Linux distribution!

The Linux Boot Sequence (Process) You might remember when you installed Linux that the installation process prompted you for a list of partitions and the sizes of each in which your filesystems would be placed.

When allocating disk space for the partitions, the first sector, or data unit, for each partition is always reserved for programmable code used in booting. The very first sector of the hard disk is reserved for the same purpose and is called the master boot record (MBR).

When booting from a hard disk, the PC system BIOS loads and executes the boot loader code in the MBR. The MBR then needs to know which partitions on the disk have boot loader code specific to their operating systems in their boot sectors and then attempts to boot one of them.

Fedora Linux is supplied with the GRUB boot loader which is fairly sophisticated and therefore cannot entirely fit in the 512 bytes of the MBR. The GRUB MBR boot loader merely searches for a special boot partition and loads a second stage boot loader. This then reads the data in the /boot/grub/grub.conf

configuration file, which lists all the available operating systems and their booting parameters. When this is complete, the second stage boot loader then displays the familiar Fedora branded splash screen that lists all the configured operating system kernels for your choice.

Boot sequence summary

• BIOS • Master Boot Record (MBR) • GRUB • Kernel • init • Run Levels

•

1. BIOS • BIOS stands for Basic Input/Output System • Performs some system integrity checks • Searches, loads, and executes the boot loader program. • It looks for boot loader in floppy, cd-rom, or hard drive. You can press a key (typically F12

of F2, but it depends on your system) during the BIOS startup to change the boot sequence. • Once the boot loader program is detected and loaded into the memory, BIOS gives the

control to it. • So, in simple terms BIOS loads and executes the MBR boot loader.

2. MBR • MBR stands for Master Boot Record. • It is located in the 1st sector of the bootable disk. Typically /dev/hda, or /dev/sda • MBR is less than 512 bytes in size. This has three components 1) primary boot loader info in

1st 446 bytes 2) partition table info in next 64 bytes 3) mbr validation check in last 2 bytes. • It contains information about GRUB (or LILO in old systems). • So, in simple terms MBR loads and executes the GRUB boot loader.

3. GRUB • GRUB stands for Grand Unified Bootloader. • If you have multiple kernel images installed on your system, you can choose which one to

be executed. • GRUB displays a splash screen, waits for few seconds, if you don’t enter anything, it loads

the default kernel image as specified in the grub configuration file. • GRUB has the knowledge of the filesystem (the older Linux loader LILO didn’t understand

filesystem). • Grub configuration file is /boot/grub/grub.conf (/etc/grub.conf is a link to this). The

following is sample grub.conf of CentOS. #boot=/dev/sda

default=0

timeout=5

splashimage=(hd0,0)/boot/grub/splash.xpm.gz

hiddenmenu

title CentOS (2.6.18-194.el5PAE)

root (hd0,0)

kernel /boot/vmlinuz-2.6.18-194.el5PAE ro root=LABEL=/

initrd /boot/initrd-2.6.18-194.el5PAE.img

• As you notice from the above info, it contains kernel and initrd image. • So, in simple terms GRUB just loads and executes Kernel and initrd images.

4. Kernel • Mounts the root file system as specified in the “root=” in grub.conf • Kernel executes the /sbin/init program • Since init was the 1st program to be executed by Linux Kernel, it has the process id (PID) of

1. Do a ‘ps -ef | grep init’ and check the pid. • initrd stands for Initial RAM Disk. • initrd is used by kernel as temporary root file system until kernel is booted and the real root

file system is mounted. It also contains necessary drivers compiled inside, which helps it to access the hard drive partitions, and other hardware.

5. Init • Looks at the /etc/inittab file to decide the Linux run level. • Following are the available run levels

• 0 – halt • 1 – Single user mode • 2 – Multiuser, without NFS • 3 – Full multiuser mode • 4 – unused • 5 – X11 • 6 – reboot

• Init identifies the default initlevel from /etc/inittab and uses that to load all appropriate program.

• Execute ‘grep initdefault /etc/inittab’ on your system to identify the default run level • If you want to get into trouble, you can set the default run level to 0 or 6. Since you know

what 0 and 6 means, probably you might not do that. • Typically you would set the default run level to either 3 or 5.

6. Runlevel programs • When the Linux system is booting up, you might see various services getting started. For

example, it might say “starting sendmail …. OK”. Those are the runlevel programs, executed from the run level directory as defined by your run level.

• Depending on your default init level setting, the system will execute the programs from one of the following directories.

• Run level 0 – /etc/rc.d/rc0.d/ • Run level 1 – /etc/rc.d/rc1.d/ • Run level 2 – /etc/rc.d/rc2.d/ • Run level 3 – /etc/rc.d/rc3.d/ • Run level 4 – /etc/rc.d/rc4.d/ • Run level 5 – /etc/rc.d/rc5.d/ • Run level 6 – /etc/rc.d/rc6.d/

• Please note that there are also symbolic links available for these directory under /etc directly. So, /etc/rc0.d is linked to /etc/rc.d/rc0.d.

• Under the /etc/rc.d/rc*.d/ directories, you would see programs that start with S and K. • Programs starts with S are used during startup. S for startup. • Programs starts with K are used during shutdown. K for kill. • There are numbers right next to S and K in the program names. Those are the sequence

number in which the programs should be started or killed. • For example, S12syslog is to start the syslog deamon, which has the sequence number of 12.

S80sendmail is to start the sendmail daemon, which has the sequence number of 80. So, syslog program will be started before sendmail.

There you have it. That is what happens during the Linux boot process.