Linux Administrator is amazing task which is managed by Administrator. Linux Team is privileged to managed the whole Linux operating system. They Mainly support infrastructure rather than application and they try to make system available for 24X7 days across the all location if application would be on cluster environment.

Main Points for Linux Admin Topics:

1. Linux is a Multiuser Operating system – (Multi user can login at a time).

2. Roles and responsibilities of Linux Administrator:

• Who can grant access for user accounts and their rights.
• Manage system security and user groups for user management.
• Installing and upgrading Linux system and software.
• Creating Linux file system.
• Patching and Upgradation of any component.
• Resolve problem
• monitors system performance and ensure compliance and its security standard.

Basic commands:

1. Linux Administrator Task- Creating user

sudo adduser Vicky

2. Verify user created or not

Command - Finger

pwr@pwr-VirtualBox:~/Documents$ finger Vicky

pwr@pwr-VirtualBox:~/Documents$  finger vicky

Login: vicky                            Name: Vicky Anand

Directory: /home/vicky                  Shell: /bin/bash

Office: 2030, 658232522                 Home Phone: 258025626

Never logged in.

No mail.

No Plan.

3. Linux Administrator Task- Adding users to users’ groups.

sudo usermod -a -G GROUPNAME vicky

sudo usermod -a -G home vicky

cat /etc/group

sudo usermod -a -G vicky vicky

cat /etc/group

sudo usermod -a -G vicky pwr

cat /etc/group

4. Linux Administrator Task- Deleting, disabling account

Disabling the account:

pwr@pwr-VirtualBox:~/Documents$ sudo passwd -l vicky

passwd: password expiry information changed.

Deleting account:

pwr@pwr-VirtualBox:~/Documents$ sudo userdel -r vicky

userdel: group vicky not removed because it has other members.

userdel: vicky mail spool (/var/mail/vicky) not found

Verify the user has been deleted or not:

pwr@pwr-VirtualBox:~/Documents$ finger vicky

finger: vicky: no such user.

5. Linux Administrator Task – Linux and Unix user management commands.

Above screen will have all command which all executed in Linux System.

Command to use:

1. Add user : sudo adduser ‘username’
2. To see user created or not : finger ‘username’
3. Add user to user group : sudo usermod -a -G GROUPNAME USERNAME
4. Remove user from user group: sudo deluser USER GROUPNAME
5. Finger : provide all logs users information.
6. Disable user : sudo passwd -l ‘username’
7. Delete user : sudo userdel -r ‘username’

You can also learn this Linux Article : How to find top 5 largest files in directories on Linux/Unix

If you want to understand more about Linux Administrator & Management. Please watch this videos.