Tài liệu Adding Users in Linux pdf

Lab 10.2.2: Adding Users in Linux Estimated Time: 20 minutes Objective In this lab, the student will learn how to create user accounts using the Linux Red Hat 7.X operating system.. Th

Lab 10.2.2: Adding Users in Linux

Estimated Time: 20 minutes

Objective

In this lab, the student will learn how to create user accounts using the Linux Red Hat 7.X operating system

Equipment

The following equipment is required for this exercise:

• Computer with Linux installed

• The computer will boot to the CLI not the GUI (not to X window at startup)

Scenario

The XYZ Company has just installed a server running Linux The company need a IT person to log onto the server and create users

Procedures

Until now, each workstation has acted independently from other computers Each student will create user accounts and these accounts will be used in later labs

To complete the steps below, each student will need to be at the command line If X Window was launched at boot up, then students will need to open a terminal window

Step 1: Account Planning

From the drawing below, plan out how many accounts will need to be added

Assign each computer a name, which will also identify its location User accounts may be added to the system name to identify not only the computer but also the user at that location

For example, systemA1 is used by students therefore a user account with the name: studentA1 will be used

Assign a password that is the same as the computer name in order to make the initial login easier

SystemA1 is in the first computer in row

A The computer name (host name) will

be systemA1 and the student account will be studentA1

In the space below, write out a user account list Include the computer being worked on

as well

Computer

Name/Location

User Account/Name Password Comments

Example of user accounts and host names

Computer

Name/Location

User Account/Name Password Comments

Windows Computer

Linux Computer

Step 2: The useradd Command

At the command prompt, type the command:

man useradd

What do the following switches do?

-c

-d

-e

Does the useradd command create a home directory for the user by default? If so where?

Step 3: The passwd Command

The useradd command by itself does not automatically allow a user to login A

password must first be assigned to the user account This is done with the passwd

command

At the command prompt, type the command:

man passwd

Briefly describe the following passwd switches:

-k

-l -u -d What other means of password protection does the man passwd page discuss?

Step 4: Adding Users

For this step, make sure to be logged in as the root user If not already root, use the su – root command with the root’s password

With the list from step 1, create accounts for all other users in the lab

Example:

Note: Part of the password for these accounts can be found in a dictionary (the word

“student”) Linux will warn against using these passwords for security reasons, but it will accept them All passwords must be entered twice

Notice that in the example above, this is a two-step process First, create the account with the useradd command and then give the new user account a password with the

passwd command

1 Type:

useradd studentXX

(where XX is the username from the table in step 1), and then press Enter

2 Type:

passwd studentXX

Use the student account for the password Linux will ask the user to enter the password twice to check for accuracy

Step 5: Account Verification

In this step, verify that the accounts were created correctly in step 4 by using the finger

command

To learn about the finger command type:

man finger

Experiment with the finger command, type:

finger root

Briefly describe the output of this command?

Verify that the accounts were created correctly in step 4 Randomly pick six accounts and use the finger command to see if they were created correctly, List the results in the table below

Account name Verified Y/N

Step 6: Deleting Users

To delete an account, the Linux administrator uses the userdel command Read the man page on the userdel command, type:

man userdel

Describe the –r switch when it is run with the userdel command

To test the userdel command create a temporary account, type:

useradd temp123

Note: This account does not need a password since this is only a temporary account

To see if the account was created, type:

finger temp123

Was a home directory created? Y/N

Next delete the temp account, type:

Does the account still exist? Type:

finger temp123

What was the output of this command?

Troubleshooting

To create accounts in Linux, the user must be logged onto the server as an

Administrator If problems are encountered while creating these accounts, verify that the user has the necessary administrative privileges by logging off of the server and logging

on again using the Administrator account

Reflection

Why is it important that only an administrator is allowed to create user accounts?