USER AND GROUP MANAGEMENT


         USER AND GROUP MANAGEMENT

In this user management we can do following commands

  1. Create user
  2. List user
  3. Change user
  4. Remove user
  5. Set password for users


1. Create user

Using mkuser command we can create a new user, suppose you want to create new user Kumar,

#mkuser kumar

After this command execution, kumar home directory created in /home/kumar/
Kumar user configuration details stored in /etc/passwd

Now you can login the terminal using kumar user name without password.

Then you have to set the password for kumar user using command passwd

#passwd kumar
Enter new password: ******
Confirm password again: ******

After this command execution password assigned to kumar user and kumar user password configuration entry added in /etc/security/passwd.

NOTE: user configuration data stored in /usr/lib/security/mkuser.sys

Whenever login the server that last login information’s stored in /etc/security/lastlog file.

2. List user

Using lsuser command we can list the user properties, i.e. user home directory, shell, group, etc. except password

#lsuser all (It will list all the user information’s except password)

#lsuser kumar (It will list only kumar user information’s except password)


3. Change user

Using chuser command we can change user properties, i.e. user home directory, shell group, etc. except password

Whenever you create a user that user home directory by default created in /home file system, and default group is staff.

Suppose we want to change the kumar user group to system, then your command will be.

#lsuser kumar (it will show kumar user properties including group information)

#chuser pgrp=system kumar (now kumar user is assigned to primary group system and secondary group is assigned to staff)

#lsuser kumar (It will list modified kumar properties, group is system, staff)

Like this we can change all the user properties


4. Remove user

Using rmuser command we can remove the user, suppose you want to remove kumar user

#rmuser kumar

After this command execution, kumar user will be deleted.


5. Set password for Users

Using passwd command we can set password for user and root

#passwd kumar

Enter new password: *****
Confirm password: *****

We are changing password for kumar user from root path, it will not ask existing password for kumar user, because root is administrator login.

Suppose you are changing password from kumar login, it will ask existing password, because user should know the existing password before changing the new password.  Otherwise any user can change the kumar user password. This not recommended security.

$pwd
/home/kumar
$passwd kumar
Enter the old password: *****
Enter the new password: *****
Confirm password again: *****

NOTE: Suppose you are forgotten root password that time what you will do.

Answer: boot the server with BOS Cd and go to maintenance mode, access the rootvg, then you can change the password for root. 

Like this we can change the password for users.


GROUP MANAGEMENT

In this group management we can do following things,

  1. Create group
  2. List group
  3. Change group
  4. Remove group


1. Create group

Using mkgroup command we can create the group, suppose you want to create oracle group.

#mkgroup oracle

After this command execution new oracle group has created and this group is added in /etc/groups file.


2. List group

Using lsgroup command we can list group information’s. Suppose we want to list oracle group information

#lsgroup oracle (it will display the oracle group information’s, gname, gid, members)

#lsgroup all (It will list all group details)


3. Change group

Using chgroup command we can change the group information’s.

#chgroup options oracle


4. Remove group

Using rmgroup command we can remove a group, suppose we want to remove oracle group.

#rmgroup oracle

After this command execution oracle group removed and group configuration information removed from /etc/groups files.