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<u>Accessing the Administrative Account (root)</u> Many administrative tasks require the root administrative account. There are many ways to access this administration account:<ul><li>Login: '''root''' (enter root password)</li><li>Switch User to root (without login):<ul><li>'''su''': Remains in regular user's directory, does not run root's startup script(s).</li><li>'''su -''' : Changes to root's home directory (/root) and runs root's start script(s).</li></ul></li></ul> <u>Obtaining System Information</u> It is always recommended to document information regarding a newly-installed Operating System for a company or organization. This information usually contains information regarding the OS (Linux distribution, Kernel version, etc) as well as running processes, hostname, etc. The following table lists the common Linux commands to help generate this OS documentation: {| cellpadding="5" border= Thinking Ahead "1" cellspacing="0"|- valign="top"|<b>Linux Command</b>|<b>Purpose</b>|- valign="top"|''' grep -i packaging /var/log/anaconda/anaconda.packaging.log ¦ wc -l'''|Obtain information regarding the initial Linux OS installation (including installed packages)|- valign="top"|'''rpm -q -a ¦ wc -l''' |Obtain number of files required to allow package(s) to be installed|- valign="top"|'''hostname''' |Display hostname of Linux machine |- valign="top"|'''uname -rv''' |Display version of Linux kernel |- valign="top"|'''ifconfig''' |Display networking information (including IP ADDR, Netmask) |- valign="top"|'''route -n''' |Display gateway information |- valign="top"|'''nslookup''' |Display nameserver information |} <u>Pathname for USB Stick</u> The default mount location has been changed in linux distributions newer than CentOS. So while we will get '''/media/usb-device-name''',<br> in newer distributions you'll see '''/run/media/userloginid/usb-device-name''' <u>Disabling SELinux</u> SELinux stands for '''Security-Enhanced Linux'''. It is a component that helps to better secure the system to protect against intrusion (hackers). SELinux is enabled upon the default install of CentOS. SELinux can be a good thing, if you take care of it and know how it works. For this course it is strongly recommended that you '''disable SELinux by default''' because we won't have the time to reconfigure it every time the labs make it necessary == Common Mistakes / Warnings == {{Admon/important |Be Aware of the Following Issues| Be aware of these common mistakes that students make that can cause problems for their future labs.}}
<u>Bring Required Materials to Class</u>
<u>Notes / WarningsParitioning</u> * '''Failure to properly following lab instructions may result in re-doing lab again!''' * '''Make certain to create the correct partitions''' (Have instructor or lab monitor confirm before proceeding with install)::'''Primary Partitions (ext4)::*'''30GB''' for '''/''' (i.e. "root"):*'''40GB''' for /home:*'''100GB''' for '''/var/lib/libvirt/images''' (need to manually enter this "mount-point"):'''Swap Partition:''':*'''16GB''' (Note: "swap" must be selected from the drop down menu) * '''NOTE:''' Remember that the sizes are recorded in MB (eg. 30 GB = 30000 MB) and you should multiply GB by a factor of 1024 to get the correct size.<br> (eg. '''30 GB x 1024 = 30720 MB''')<br><br>
* How many files (correct to the nearest hundred) were installed?
* How many users were created automatically on your system (regular, admin)?
* List 3 2 ways that you can access your root account
* What is the difference between the commands '''su''' and '''su -''' ?
* What is the home directory for the user "root"?
