Managing users in Linux Systems.

09 May 2017

Managing users and groups

In all machines, we should create an user to manage the system.
Best way to create users and groups, Recommended:

  • Create/Delete new group:

    sudo addgroup jclustergroup
    sudo delgroup jclustergroup
    
  • Add/Delete user to a specific group or system (empty):

    sudo adduser juser [jclustergroup/empty]
    sudo deluser juser [jclustergroup/empty]
    
  • Add/Change password to user:

    sudo passwd juser
    

We can use lower/upper case in names, Not recommended:

  • Create/Delete new group:

    sudo groupadd JClusterGroup
    sudo groupdel JClusterGroup
    
  • Create/Delete new user:

    sudo useradd Juser
    sudo userdel Juser
    
  • Create new user with a group named JClusterGroup with home /home/juser and with CLI /bin/bash

    sudo useradd -g JClusterGroup -d /home/Juser -m -s /bin/bash Juser
    
  • Change users permissions:

    sudo chown -R <username> <files>
    

    own

  • Change groups permisions:

    sudo chgrp -R <groupname> <files>
    

    grp

  • Change actions permissions:

    sudo chmod ugo-rw+x <filename>
    

    We add execution permission without read/write permission.