Redhat: Users

User, Groups and Redhat

In order to make use of a system, users need to be able to access it. The administrator must understand how to create, remove and modify users and groups of users. There are several ways this can be done, using the useradd command, manually editing the passwd files or through the GUI.

By default there is only one user of a fresh install of Redhat - the Root user. No other users are needed, but for security purposes it is better to have at least one regular account so that the root account is only used when needed.

Types of Users

There are three types of users on Redhat:

Regular Users	Users of the system to which rights can be given if needed	michael, dave, roshan
Admin / Root Users	the Admin User	root
Service Users	services running on the system, cannot be logged into (otherwise theres a security issue)	apache, samba

User IDs

Redhat User IDs for Regular Users and Groups start at 500. The maximum User ID is set the the login.defs file. This is usually set at 60000 by default. But Redhat can support user IDs upto 4 billion. Limited the User IDs to 60000 allows otehr services to use the higher IDS.