Summary and Resources

Users and groups work essentially the same way in Linux that they do in Windows, except that only one group can be associated with a system resource. To think about groups in Linux, consider groups to be cheap and don't be afraid to create a lot of them for a complex environment. Create your groups based on resource access rather than on business units.

User and group information are stored in the /etc/passwd and /etc/group files, respectively. Your system will also probably have an /etc/shadow and /etc/gshadow file, which contain the encrypted passwords for added security. It is possible to work with users and groups by editing these files directly, but this should be done with great care.

All user and group functions can be handled from the console, which makes them scriptable. Tools, such as Webmin, also provide graphical ways of working with users and groups.

Resources

• Check out the other parts in the Windows-to-Linux roadmap series.
  
  
• The Linux System Administrator's Guide, Chapter 11. Managing user accounts is an older document, but is still relevant as general user and group techniques haven't changed. The guide is also a good read to learn more about console-based administration of Linux.
  
  
• The Linux Headquarters site features some good basic tutorials and tips covering many topics. Their tag line is "I've installed Linux... now what???" You may also be interested in their tutorials.
  
  
• The Linux Documentation Project also has a list of HOWTOs by category to help you find relevant documentation quickly and easily.
  
  
• Adding users with GUI system tools is also covered in "Basic tasks for new Linux developers."
  
  
• User administration is also covered in the developerWorks tutorial, "LPI certification 101 exam prep, Part 3: Intermediate administration".
  
  
• IBM Directory Server implements the Lightweight Directory Access Protocol (LDAP) for accessing directory services, especially those that are X.500 based. Read "Authenticating Linux users with IBM Directory Server" for details.
  
  
• File permissions and security are addressed in Chapter 3 of the Introduction to Linux guide at the Linux Documentation Project.
  
  
• Read more about Users and Logins in this chapter from Linux Unleashed (Macmillan Computer Publishing, 1998) and in Managing Accounts and Groups from The Official Red Hat Linux System Administration Primer (Red Hat, 2002).
  
  
• The University of Maryland shares words of wisdom on the selection of secure passwords
  
  
• The Red Hat Linux Manual documentation offers more detail on the use of Shadow password file.
  
  
• The Linux Shadow Password HOWTO gives background history and rationale on the shadowing system as well as step-by-step guidelines for implementation.
  
  
• System security is a vast and complex topic, but in an interconnected world, it affects everyone. Luckily, it is never too early nor too late to get started with it. The documents Adding Security to Common Linux Distributions and Strategies for Keeping a Secure Server (which is the twelfth chapter from the earlier referenced Linux Administration Made Easy guide) will help you to do just that.
  
  
• The IBM developerWorks article "Addressing security issues in Linux" will help you get started with basic security.
  
  
• "Technical FAQ for Linux users" (developerWorks, July 2001) offers another perspective on making the change from Windows to Linux.
  
  
• For getting started with IBM software on Linux, there's no better resource than the Speed-start your Linux app page. You'll find installation tips and links to resources for DB2, Lotus Domino, WebSphere Application Server, WebSphere Studio, and more. You can also sign up to receive a free Linux Software Evaluation Kit, containing trial software and training resources.
  
  
• Find more resources for Linux developers in the developerWorks Linux zone.