INSTALLATION Q & A - 3

INSTALLATION  INTERVIEW QUESTIONS AND ANSWERS

PAGE - 3

21..Describe Linux boot-up sequence?

BIOS (Basic Input-Output System) --> MBR (Master Boot Record ) --> GRUB ( Grand Unified Bootloader ) --> Kernel --> INIT ( First Process ) --> RUNLEVEL

22..What is  INODE in Linux?

In Linux every thing is FILE. And we store our data in the file. The information about these file are called metadata. these meta data are nothing but it's "INODES" which contain information about files.

23..What is the file server in Linux server?

A file server differs from a personal computer (PC) in that the server is dedicated to storing files in a centralized location while permitting access to networked computers

24..How does the linux file system work?

Linux file structure is a tree like structure. It starts from the root directory, represented by '/', and then expands into sub-directories. All the partitions are under the root directory. If a partition is mounted (The mount point defines the place of a particular data set in the file system) anywhere apart from a “device”, the system is not aware of the existence of that partition or device. Directories that are only one level below the root directory are often preceded by a slash, to indicate their position.  

25..What is  fork? and how  does it work in linux?

System call fork() is used to create processes. It takes no arguments and returns a process ID. The purpose of fork() is to create a new process, which becomes the child process of the caller. After a new child process is created, both processes will execute the next instruction following the fork() system call. Therefore, we have to distinguish the parent from the child. This can be done by testing the returned value of fork():

26..What is the difference between ssh and telnet in Linux operating system?

Both Telnet and SSH is used for remote Log-In and to trasnfer data.   

Telnet -> Telecommunication network 
It is not secure and anyone can use it. It uses ASCII format. 
Information sent and received can be easily read by anyone (Hackers) in that network. 

SSH -> Secure Shell 
It is highly secure. 
Information passed accross the network is encrypted. 
Hackers will not be able to read your data. 

27..What is the core of Linux Operating System?

A..The kernel is the core of an operating system: it manages communication between devices and software, manages the system resources (like CPU time, memory, network,

B..The system libraries contain program methods for developers to write software for the operating system.

C..The system tools are built using the system libraries and enable administrators to administer the system: manage processes, navigate on the file system, execute other applications, configure the network, ...

D..The development tools provide the means to build new software on (or for) the system.

28..How you will troubleshoot system if boot partition is missing in linux?

Reinstall  the  corrupted  boot partition

29..Explain  the   linux  boot process?

Linux startup process is the multi-stage initialization process performed during booting a Linux installation. It is in many ways similar to the BSD and other Unix-style boot processes, from which it derives.

Booting a Linux installation involves multiple stages and software components, including firmware initialization, execution of a boot loader, loading and startup of a Linux kernel image, and execution of various startup scripts and daemons. For each of these stages and components there are different variations and approaches; for example, GRUB, LILO,SYSLINUX or Loadlin can be used as boot loaders, while the startup scripts can be either traditional init-style, or the system configuration can be performed through more modern alternatives such as systemd or Upstart.

30..How to keep the track of all the commands run by the user(s) in Linux

Check the .bash_history file in user's home location

# less /home/raju/.bash_history