Difference between revisions of "Linux for Sys-Ads"

Revision as of 04:02, 27 April 2020

Linux System Administration

Linux is one of the most popular Operating Systems used in today's world. Linux refers to the family of Unix-like computer operating systems using the Linux kernel. Linux can be installed on a wide variety of computer hardware, ranging from mobile phones, tablet computers and video game consoles to mainframes and supercomputers. It is open source software and the Linux kernel is released under the GNU General Public License and hence can be freely created, modified and distributed.

As Linux is a free operating system, it can be widely used in educational or business institutions without incurring extra cost for licensed operating systems. So, it becomes extremely important to manage Linux computer systems efficiently for configuration, resource allocation and reliable operation.

The job of a Linux systems administrator is to ensure all the above mentioned parameters, specifically creating groups and user, modifying process execution priorities, manage storage and memory, logging, data backup, task automation etc. This series of tutorials on Linux System Administration will help you master all of topics that are needed for becoming successful system administrator.

In this series of tutorials, we will learn the following topics:

User and Group Management

1. Creating user account
   • adduser command
   • Define specify user ID
   • Define specify home directory
   • Define specify login shell
   • Give comments during user creation
   • About user id's
   • /etc/passwd file
   • /etc/shadow file
   • About the fields in /etc/passwd and /etc/shadow files
2. Assigning Groups on User Creation
   • Creating a user group
   • addgroup command
   • Group id
   • Assigning user to the group
   • Creating user group with specific group id
   • Assigning groups to users at the time of account creation using "ingroup" option
   • Assigning groups with gid to users at the time of account creation
   • /etc/group file
   • /etc/passwd file
   • Fields of /etc/group file
   • "id username" command
3. User Password management
   • Changing user password
   • Locking user password
   • Unlocking a password
   • Password removal
   • Changing the password expiry information
   • passwd command
   • passwd -S
   • passwd -aS
   • passwd -d
   • Minimum age, maximum age, warning period, and inactivity period for the password.
   • /etc/shadow file
4. Modifying User Account
   • usermod command
   • Modifying attributes of user account
   • Locking user account
   • Unlocking user account
   • Change home directory
   • Change shell
   • Change comments
   • Locking user password
   • Unlocking a password
   • Man command
5. Group Password and Login
   • newgrp command
   • /etc/group
   • /etc/gshadow
   • Changing current group
   • Securing a group with password
   • Login to a group as group member
   • Login to a group as non-member
   • Login to group with password
   • Login to group without password
   • Exit from group login
6. Administrating Group with gpasswd Command
   • Group password
   • Adding group member
   • Adding group administrator
   • Deleting member
   • Removing password
   • Restricting password
   • Login to a group as group member
   • Login to a group as non-member
   • gpasswd
   • newgrp
7. Modifying and Deleting Groups
   • groupmod command
   • groupdel command
   • Change group name
   • Change GID
   • Check existing GID
   • Set same GID
   • Set GID for the files
   • Delete group
   • Delete user
   • /etc/passwd

Process Management

Memory management

Storage management

System startup and runlevel

Network management

Logging

Automating and scheduling tasks

Backup

The Spoken Tutorial Effort for Linux System Administration has been contributed by Antara Roy Choudhury, Praveen S., Nancy Varkey and Srikant Patnaik.