Lab #5 Guide:
Installing CentOS as a
Virtual Machine
CTEC1863/2019F
Operating SystemsMike Boldin
Tools, Materials and Equipment
• Oracle VirtualBox software
– official site: https://www.virtualbox.org/
• CentOS 7 DVD-R or .iso file
– official site:https://www.centos.org
– download link:http://isoredirect.centos.org/centos/7/isos/x86_64/
• Minimum 20 GB of hard disk space
• USB 3.x flash drive (min. 32 GB) or hard diskCTEC1863 CentOS VM Guide 2
PLEASE READ FIRST!
• Important background information and examples regarding the following topics can be found in the "Installing Ubuntu as a Virtual Machine" guide
– VirtualBox
– PCs in L17
– Setting up a virtual machine (VM)
– Backing up a VM
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CentOS
• Recommended requirements:
– 1 GB RAM
– 20 GB disk space
• https://wiki.centos.org/About/Product
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CENTOS INSTALLATION GUIDECTEC1863
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New Virtual Machine Example
• The following are actual screen shots from the installation on an L17 Dell PC, eight-core i7 processor, 32 GB RAM, running Windows 10 (No Hyper-V).
• My VirtualBox version is 6.0.10.
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New
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CentOS is part of the Red Hat family of Linux distributions. It is comprised mainly of all of the GPL-licensed packages from Red Hat Enterprise Linux (RHEL).
New: Storage
I am using a maximum of 15 GB on SSD. On your own PC, you may use a larger size.
Don’t forget to also add the VBoxGuestAdditions.iso as a virtual optical drive.
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VM Created
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I used many of the same settings as for my Ubuntu VM; other settings are similar:
• 4 GB RAM• 64 GB VRAM• Bridged network
VM Created
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Start
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The default is to test the media; press the I key to switch to “Install” and then press Enter.
Installer - Language
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Installer - Settings
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2 3
4 Network (not shown here)4
1. Time Zone
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2a. Software Selection
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Choose“Server with GUI”
“FTP Server” is shown; scroll down for more…
2b. Software Selection
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Choose“Server with GUI”
Also add “Compatibility Libraries”,“Development Tools” and“System Administration Tools”
3a. Installation Destination
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2
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3b. Installation Destination
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3c. Installation Destination
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4. Network & Host Name
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Turn network ON;We are using DHCP, so IP addresses and Host name do not need to be set…
5. Ready to Begin
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After you choose your Software and set the Source, the “Begin Installation” button will become active(and the warning triangles will disappear…)
5a. Configuration
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1 2
5b. Root Password
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CentOS still creates a root (Administrator) user, which you will need to switch to, from time to time, for system admin tasks.
5c. Create User
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I prefer using root for sysadmin tasks, but you can also set up sudo(like in Ubuntu).
6a. Installing…
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6b. Installing…
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6c. Installation Complete
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The installation process may take 5 or 10 minutes (depending on your overall computer speed.)
Start: VirtualBox POST Screen
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I can press F12 to bootfrom a VirtualCD-ROMdrive;the defaultorder isdefined inthe VMSettings.
VirtualBox Boot Menu
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First Boot: CentOS Boot Menu
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7a. Initial Setup
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2
The license is simply the GPL.
I turned the network ONearlier…
7b. GPLv2
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2
7c. Initial Setup Complete
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8a. Login Screen
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List of users is here. If you click on “Not listed?”, you can log on directly as root.
Reboot and shutdown can be found here.
8b. Welcome
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8c. GNOME Help
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GNOME Desktop
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GNOME System Menu
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Volume
Network
Switch user
Control Panel
Lock screen
Shut down/Restart
Date, time & calendar
GNOME Applications Menu
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From the Applications menu, open the Utilities sub-menu. Screenshot and Terminal are near the bottom.
Terminal is also in the list of common apps.
Terminal
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From the Edit menu, choose Profile Prefences to customize
Becoming root
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The su command, which stands for "switch user", is used to temporarily log on as the root user -- the system administrator.
The command line is: su -
On success (after entering the root password), the prompt character
changes to a #.
Updating CentOS
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The yum command, which stands for "Yellowdog Updater Modified" (but could also mean "yet another update manager"), is one of the tools used to manage software on RedHat Linux. To download and install updates, the command line (as root) is:
yum update
Updating CentOS (2)
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First, yum connects to a near-by mirror site to check software repositories for updates. It will then identify the packages that require updating...
Updating CentOS (3)
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After confirmation, yum will download and then install the updates. Note, after installation, the first update is quite large, as enough time has passed since the ISO image was created.
Updating CentOS (4)
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Finally, yum will install the downloaded updates in the correct order. If critical operating system components, such as the boot manager, (especially the) kernel, or runtime libraries have been updated, it is a good idea to reboot.
Updating CentOS (5)
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From time to time, there will be no available updates…
Installing Guest Additions
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As root, you must install pre-requisite software before installing the GAs.
Read the following article:
VirtualBox Guest Additions on Fedora 30/29, CentOS/RHEL 7.6/6.10/5.11
Installing Guest Additions (2)
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Same procedure as for Ubuntu:
1) Install the pre-requisite packages first;
2) From the VM menu, “Insert the GA image…”;
3) Run the installer software.
4) Or switch steps 1) and 2) and then find the mount point for the image and run the installer from the Terminal (shown here…)
Installing Guest Additions (3)
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This is a SUCCESSFUL, command-line install…
Installing Guest Additions (4)
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When graphical system administration tasks require rootaccess, the desktop will ask for authentication (similar to Ubuntu and Windows...).
Enter the root password.
Installing Guest Additions (5)
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The VBGA installer will open up a temporary Terminal window to install itself.
Installing Guest Additions (6)
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When the installer has completed, press Enter to close the window and restart CentOS.
This is a SUCCESSFUL, Desktop install…
Changing the Display Resolution
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After restarting, from the "system" menu at the top right, start the Settings app again.
This time, select Displays.
The default resolution is 800 x 600, which is too small for a modern, graphical Linux GNOME desktop.
Changing the Display Resolution (2)
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In L17, 1280 x 960 works well on the ViewSonic or Dell monitors, butyou can choose whatever fits on your particular monitor.
THE ENDCTEC1863 CentOS Guide
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For more information, see:
https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/