Red Hat Enterprise Linux 5 Administration Unleashed

CHAPTER 9Managing Users andGroupsIN THIS CHAPTER. What Are Users and Groups?. Managing Users. Managing Groups. How It All Works. Best PracticesWith Red Hat Enterprise Linux, all users must enter ausername and password combination to use the operatingsystem and applications for security. Privileges and accessto specific files and directories can be granted or deniedbased on a person’s username. Thus, part of an administrators’duties is to manage their company’s database of usersand groups as employees change, request more storage, andtransfer to different departments. Although adding usersand groups seems like a simple task on the surface, it doesrequire forward planning and preparation for a large usergroup such as one for a large company or corporation orfor an organization that requires users to have access tomultiple computers throughout the same building or evena set of worldwide offices.This chapter explains how to manage local users andgroups. Local users and groups are authenticated by thesystem on which they are logging in to. The files storingusernames, groups, and passwords are all on the localsystem. Users and groups can also be authenticated from anetwork server. For details on network services that allowidentity management from a central server, refer to Chapter12, “Identity Management.”Even if you are using remote identity management, it isrecommended that you read the first section “What AreUsers and Groups?” and the last section “Best Practices.”The last section provides tips on managing usernames,managing passwords, deleting accounts, and structuringhome directories. The methods in this section apply to usermanagement regardless of whether the authentication takesplace on the local system or from a remote server.