You can have great control over how your Linux installation is set up and configured. You can configure users and groups and control almost all aspects of the user environment. Any variables or system-wide functions you may need to run can be kept in the /etc/bashrc or /etc/profile script.
You can set up quotas to limit the user's disk usage. You can set up one quota per partition and set soft and hard limits for users. With grace periods, you can set up a soft limit to give users an appropriate warning.
By default, Red Hat Enterprise Linux assigns unique user and group ID numbers to each new user. This is known as the user private group scheme. This scheme allows you to configure special groups for a specific set of users. The users in the group can be configured with read and write privileges in a dedicated directory, courtesy of the SGID bit.
RHEL 5 includes powerful tools for securing critical commands, using Pluggable Authentication Modules (PAM). You can use centralized account management with an NIS or LDAP service.