Birmingham mumbai

[
 37 
]
2
Managing Users and 
Permissions
In the previous chapter, we set up our very own Ubuntu Server installation, and we 
can now learn how to maintain it, starting with a look at managing who is able to use 
our server.
As an administrator of Ubuntu servers, users can be your greatest asset and also 
your biggest headache. During your career, you'll add countless new users, manage 
their passwords, remove their accounts when they leave the company, and grant or 
remove access to resources across the filesystem. Even on servers on which you're 
the only user, you'll still find yourself managing user accounts, since even system 
processes run as users. To be successful at managing Linux servers, you'll also 
need to know how to manage permissions, create password policies, and limit who 
can execute administrative commands on the machine. In this chapter, we'll work 
through these concepts so that you'll have a clear idea of how to manage users and 
their resources.
In particular, we will cover:
•  Understanding users and groups
•  Understanding when to use 
root
•  Creating and removing users
•  Understanding the 
/etc/passwd
 and 
/etc/shadow
 files
• 
Distributing default configuration files with 
/etc/skel
•  Switching users

---

Managing Users and Permissions