2.  In June 1971, Richard Matthew Stallman joined MIT Artificial Intelligence Laboratory as a programmer where he gained popularity with the hacker community and came to be known by his now popular name RMS. At that time, all the programmers used to share their code freely among each other cutting across various institutions.  In 1980, with the advent of portable software - ie software that can be compiled to run on different computers, a business model emerged where in, the companies developing the code refused to share the code with their clients and began restricting copying and redistribution of their software by copyrighting it.  In response to this trend, Stallman, who believed in the principle that software has to be free always, founded the Free Software Foundation and in 1985, published the GNU Manifesto. This manifesto outlined his motivation for creating a free OS called GNU, which would be compatible with Unix.Free Software Foundation GNU Manifesto  In the same year (1985), a professor by name Andy Tanenbaum wrote a Unix like Operating system from scratch based on System V standards POSIX and IEEE for the Intel i386 platform. He named it Minix.Minix  In 1989, Stallman released the first program independent GNU General Public Licence now popularly known as GPL or copyleft.GNU General Public Licence  In 1990, A finnish student by name Linus Torvalds studying in the University of Helsinki came into contact with Andy Tanenbaum's OS, Minix. Linus wanted to upgrade Minix by putting in more features and improvements. But he was prohibited by Tanenbaum to do so. Then Linus decided to write his own kernel and released it under GPL. This kernel is now popularly known as Linux.

3.  Reliability Linux is known for reliability often referred to as “uptime” and can easily manage the necessary workloads in today’s business environment. In addition to enterprise focused applications, the stability and relative low cost of Linux has prompted companies to integrate Linux technology into consumer devices such as Sony’s PlayStation 2  Scalability The release of the 2.4 kernel means the fastest growing OS can handle large business workloads that once could only be addressed by closed, proprietary platforms and solutions. Some examples: - 16-way symmetrical multi-processing - Network stack and file system modifications to enhance performance and scalability - Support for up 64Gb of RAM on Intel-- RAM now limits the number of run-time processes  Security Linux is one of the most secure operating systems. “Walls” and flexible file access permission systems prevent access by unwanted visitors or viruses  Open Source Licencing Model (ROI) If you develop software that requires knowledge or modification of the operating system code, Linux’s source code is at your fingertips. Most Linux applications are Open Source as well.

4.  The central module of an operating system. It is the part of the operating system that loads first, and it remains in main memory. Because it stays in memory, it is important for the kernel to be as small as possible while still providing all the essential services required by other parts of the operating system and applications. Typically, the kernel is responsible for memory management, process and task management, and disk management.moduleoperating systemmain memory applicationsprocesstaskdisk A kernel connects the application software to the hardware of a computer.

5.  In a monolithic kernel, all OS services run along with the main kernel thread, thus also residing in the same memory area.  This approach provides rich and powerful hardware access. Some developers, such as UNIX developer Ken Thompson, maintain that it is "easier to implement a monolithic kernel“ than microkernels.  The main disadvantages of monolithic kernels are the dependencies between system components — a bug in a device driver might crash the entire system — and the fact that large kernels can become very difficult to maintain.  E;g linux

6.  A micro kernel prefers an approach where core functionality is isolated from system services and device drivers (which are basically just system services).  For instance, VFS (virtual file system) and block device file systems (i.e. minixfs) are separate processes that run outside of the kernel's space, using IPC (Inter-process communication is any mechanism which allows separate processes to communicate with each other, usually by sending messages)to communicate with the kernel, other services and user processesInter-process communicationmessages  advantage to a micro kernel is that any failed service can be easily re- started, for instance, no kernel halt if the root file system throws an abort.  disadvantage to a micro kernel is that asynchronous IPC messaging can become very difficult to debug  E,g minix

8.  Ubuntu  Mint  Fedora  Debian  openSUSE

9.  CLI (non-graphical Linux) Minimum Requirements  486dx or 100% compatible processor  8mb ram (16mb recommended)  CDROM drive  1.44mb floppy drive (for boot floppy, if needed)  Monochrome (2 color) monitor  Minimum Requirements for with X-window  486dx or 100% compatible processor  16mb ram (24mb recommended)  dual-speed CDROM (quad-speed or better recommended)  1.44mb floppy drive (for boot floppy, if needed)  VGA monitor and video card  a mouse (serial, ps/2, usb)  Recommended Specs  Pentium 200MHz  64MB ram  8x CDROM  1.44mb floppy drive (for boot floppy, if needed)  VGA monitor and video card capable of handling at least 16 bit color  a mouse with a scroll wheel

10.  Minimum › 512 MB RAM › 750 MB hard disk space for software › 750 MB hard disk space for user data  Recommended › 512 MB to 4 GB RAM, at least 256 MB per CPU › 4 GB hard-disk space › Network interface (Ethernet, wireless or modem) › For Xen virtual host server—atleast 512 MB RAM for each virtual host server › For KVM virtual host server—the limits are equal to those of SUSE Linux Enterprise Server › For print servers a relatively faster processor or additional processors to improve server-based printing › For web servers additional RAM to improve caching, and additional processors to improve web application performance › For database servers—additional RAM to improve caching, and using multiple disks for parallel I/O › For file servers—additional memory and disks, or a Redundant Array of Inexpensive Disks (RAID) system to improve I/O throughput

11. Installation from one or more CD-ROMs, DVD From packages located on the hard disk FTP server across the network HTTP web server across the network NFS server across the network SMB server across the network VNC (Virtual Network Computing) server across the network

12.  Reasons To create multiple OS To create multiple partitions within an OS To differentiate the types of file systems  Methods Automatically partitions Manual partitioning with graphical partitioning tools such as Disk Druid Use fdisk utility Use GNU parted

13.  It is the act or practice of dividing the storage space of a hard disk drive into separate data areas known as partitions.  A partition editor program can be used to create, delete or modify these partitions.  Once a disk is divided into several partitions, directories and files of different categories may be stored in different partitions.  More partitions provide more control but too many may become cumbersome.

14.  MINIMUM › Partition for root directory (Primary) › Partition for virtual memory (swap memory)

15. Partition Purpose /usr This is where most executable binaries, the kernel source tree and much documentation go. /var This is where spool directories such as those for mail and printing go. In addition, it contains the error log directory. /opt This directory is reserved for all the software and add-on packages that are not part of the default installation /tmp This is where most temporary data files stored by applications. /boot This is where the kernel images and boot loader configuration go. /homeThis is where users home directories go.

16.  It is the first software program that runs when a computer starts.  It is responsible for loading and transferring control to the kernel software.  Then the kernel, initializes the rest of the operating system.

17.  which is installed by default  is a very powerful boot loader.  GRUB can load a variety of free OS, as well as proprietary OS with chain-loading (the mechanism for loading unsupported operating systems, such as DOS or Windows, by loading another boot loader).

18.  is a versatile boot loader for Linux.  It does not depend on a specific file system,  can boot Linux kernel images from floppy diskettes and hard disks.

19.  loadlin is a Linux boot loaderthat runs under DOS or Microsoft Windows (95, 98 or Me only). It allows the Linux system to load and replace the running DOS/Windows without altering existing DOS/Windows system files.  loadlin and the Linux kernel are both files on a file system accessible to DOS/Windows. It loads the Linux kernel into memory from a file.  It also places various configuration parameters into memory, and transfers control to the kernel. The kernel reads these parameters, initializes and runs, replacing DOS/Windows completely.

20.  The original SYSLINUX, used for booting from FAT filesystems (such as floppy disks and USB drives  SYSLINUX is not normally used for booting full Linux installations since Linux is not normally installed on FAT filesystems  it is often used for boot or rescue floppy discs, Live USBs, or other lightweight boot systems