Samuel Miller

HONR 269L:

Here, my research group installed centOS 7 on some linux machines in the computing cluster.

To start, one would download centOS 7 on a usb and created a bootable drive (this was already done and we did not do this part)

To create a bootable drive, use: # dd if=/iso/CentOS-7-x86_64-DVD-1602-99.iso of=/dev/sdb

Next, the centOS guide gives five steps to begin installation:

1. Disconnect any drives which you do not need for the installation. See USB Disks (x86) for more information.

2. Power on your computer system.

3. Insert the media in your computer.

4. Power off your computer with the boot media still inside.

5. Power on your computer system. Press F11 for BIOS settings (boot menu).

On the boot menu, choose 'install centOS 7'.

After installation, run initial setup: # systemctl enable initial-setup.service

- To change boot options previously set: # touch /.unconfigured

- Reboot machine.

Note: I did not actually perform these tasks, but researched about them.

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Here, I install centOS 7 onto my virtualbox vm as a 'practice run':

- I downloaded the official dvd iso from centOS website

- I hit new to make a new configuration in virtualbox

- I gave appropriate name and chose linux, then redhat, what centOS is based on, then set memory allocation, and created a virtual hard disk (First 2 rows of images)

- Next, I hit settings > storage. On the IDE controller, I added a new optical drive and click on the downloaded iso file (third row of images)

- Then I ran the vm, and a language selection screen appeared. I then selected configuration settings (software as a computational node), and began installation. (fourth row)

- Then, I created a root password and an admin user and ran configuration, then rebooted. Then I logged in with the credentials I had made and it works!! (fifth row)

- Trouble I ran into: The vm locks your mouse inside. A quick workaround is to use the swiping three fingers down gestures, which will minimize all tabs

Next, I had to ensure that the network was set up properly:

- I ran # dhclient to set up the initial network settings

- Then, # ping google.com, and it pinged over and over ([Ctrl] + c to stop)

- Then, # yum search redis

- Then, I edited a yum repo: # nano /etc/yum.repos.d/CentOS-Base.repo

- In the repo, I uncommented the baseurl (remove the '#")

- Lastly, I ran # yum update to update

However, the screen resolution this whole time was tiny, and in an effort to fix that, I updated virtualbox and broke the whole network connection

- This happened:

> # ping google.com

< Network or Hostname Unknown

> # ping 8.8.8.8

< connect: Network is unreachable

After over an hour of searching and (maybe) crying, I found a fix:

- In /etc/sysconfig/network-scripts/ifcfg-enp<number>, I changed the setting ONBOOT="yes"

- Then, I performed a network reset: # service network restart

Note: I wanted to do this manually instead of reinstalling centOS in order to get a better sense of how centOS functions. A clean reinstall may also work, but this is for practice, so I was messing around in the name of research.

In an effort to change the screen resolution:

- I downloaded the virtualbox guest additions iso and added it as an optical drive for the centOS 7 vm.

- Then, I made a directory for it and mounted the drive:

> # mkdir /media/VirtualBoxGuestAdditions

> # mount -r /dev/cdrom /media/VirtualBoxGuestAdditions

Problem they encountered when installing on the real system: BIOS vs UEFI (We need to use UEFI)

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HONR 268N:

Here I learned about basic linux commands (such as cd, mkdir, etc), and how to navigate a linux system.

Here I learned how to write C++ code in emacs and compile and run it using a linux terminal.

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Here I learned how to use logic statements and if-else statements in C++, as well as how to define pointers and get the address and value of pointers.