How unit 1 is examined
This unit covers what Unix/Linux is, how it is installed and what hardware it needs, why it is popular, and its features with the kernel. No topic was asked in recent papers, so each is kept short.
Concepts, Unix/Linux Installation and Hardware Requirements
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Definition. <mark>Unix is a multiuser, multitasking operating system developed at Bell Labs in 1969, and Linux is a free, open-source Unix-like operating system built around the kernel written by Linus Torvalds in 1991.</mark>
Key points.
- Installation steps are: boot from a live USB or DVD, choose language and keyboard, partition the disk (at least root
/and swap), select the time zone, create the user and password, then copy files and install the boot loader (GRUB). - A typical desktop needs a 1 GHz or faster processor, 2 GB RAM, and 25 GB of disk space.
- A text-only server install runs in far less, for example 512 MB RAM and 2 GB disk.
- Swap space is usually kept about equal to RAM on small systems.
Advantages of Unix/Linux and Reasons for Popularity
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Definition. <mark>Linux is popular because it is free, stable, secure and customizable, and it runs on everything from phones to supercomputers.</mark>
Key points.
- It is free and open source, so anyone can use, modify and share it without licence fees.
- It is stable and reliable, and servers run for months without a reboot.
- It is secure, because of strict file permissions, multiuser design and quick community patches.
- It is portable and flexible, running on many hardware types, with a large community and many free tools.
Features of Unix/Linux, Kernel and Kernel Functions
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Definition. <mark>The kernel is the core of the operating system that sits between hardware and programs and controls the CPU, memory and devices.</mark>
Key points.
- Main features are multiuser, multitasking, portability, a hierarchical file system, shell and pipes, and security through permissions.
- Everything is treated as a file, including devices.
- Kernel functions are process management, memory management, file system management, device management and system calls.
- The Linux kernel is monolithic but loads modules dynamically.
Last-minute revision
- Unix was created at Bell Labs in 1969; Linux kernel by Linus Torvalds in 1991.
- Linux is free, open source and multiuser.
- Install steps: boot, partition, user setup, copy files, GRUB.
- Minimum desktop: 1 GHz CPU, 2 GB RAM, 25 GB disk.
- Partitions needed: root
/and swap. - Advantages: free, stable, secure, portable, community.
- Kernel manages processes, memory, files and devices.
- The kernel is monolithic with loadable modules.
- Everything in Linux is a file.
Memory hooks
- "FSSP": Free, Stable, Secure, Portable for advantages.
- "PMFD": Process, Memory, File, Device for kernel functions.
- Kernel is the hub between hardware and software.
Coverage checklist
- Concepts, Unix/Linux Installation Process, Hardware requirements for Unix/Linux: no past questions.
- Advantages of Unix/Linux, Reasons for Popularity and Success of Linux/Unix Operating System: no past questions.
- Features of Linux/Unix Operating System, Kernel, Kernel Functions: no past questions.