= INVESTIGATION 1: User/Group File System Management =
User account management is a very important operation that a Linux sysadmin does on a consistent basis. The sysadmin not only needs to add or remove user accounts by issuing commands, but may need to automate user account creations a large number (batch) of potential employees. There are many features with the Linux command to create new users including: specification of a home directory, type of shell used, name, password and time-limit (referred to as "aging") for a new user account. Remove user accounts also have options such as removing the user account but keeping the home directory for reference or evidence of "wrong-doing"
In your ULI101 course, you learned to change permissions for directories and files relating to user, same group members and other group members. In this course, since you are the sysadmin with root privileges, you can create or remove groups as well as change the ownership of directories and files! We will now learn to perform key user account management operations in this section.
== Part 1: The /etc/passwd file ==
'''Answer the Part 4 observations / questions in your lab log book.'''
=INVESTIGATION 2: Managing Adjusting File System Services and Run-levelsSizes with LVM=
Many students may think that the following topic is small and "not a big deal". Those students may say, '''"How hard is running Monitoring and stopping services?"''' The process may not be hard, but knowing how to stop, start, restart and check the status of services is absolutely critical to ensuring adequate space for a Linux server. '''Aside from learning to troublefile-shoot problems''' by checking the status of running services, '''understanding how to manage services is critical to help protect a Linux server from penetration''' (this term is referred to as "'''Hardening a system'''"). Sometimes it is "what we don't know" that can harm us. One key element in hardening a computer system is considered to disable non essential networkng services to allow IDSs ('''Intrusion Detection Systems''') to focus on be an important task for a narrower range of policy violations. A Debian-based penetration testing distribution called Kali (formerly referred to as '''BackTrax''') allows sysadmins and security professionals to identify vulnerabilities in their computer systems, and thus improve (harden) their systems against penetration. Learning to monitor the status, enable and disable networking services underlies the '''Backtrax''' motto:<br><br>'''''"The quieter you are, then more you will hear..sys admin."'''''<br><br>
=== Part 1: How do we Manage System Services? ===