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IBM LINUXONE

The IBM LinuxONE is a family of servers built to host enterprise Linux applications. Its architecture, known as s390x (short term for 64-bit Z), is designed to pack more compute power into every CPU core (drive more processing with fewer cores).

The IBM LinuxONE Community Cloud provides free access to developers, students, and entrepreneurs to virtual servers (e.g. RedHat, SUSE, Ubuntu) and services for testing and piloting emerging applications for evaluation purposes.

The LinuxONE is a service which provides virtual servers above a virtual machine (VM) manager called Hypervisor, running on IBM Z.

Yellowdog Linux: a RedHat-based old Linux distribution. The Yellowdog Updater, Modified (YUM) is a software-package manager under RedHat.

1. SETTING UP

Register for LinuxONE:

• visit the site: https://community.ibm.com/zsystems/l1cc/

• select Try Linux Virtual Machines...

• enter data; for EventCode enter IBMZXPLORE

• press Submit

• wait for email confirmation

• service link: https://linuxone.cloud.marist.edu

• alternative is the LinuxONE Community Cloud: https://developer.ibm.com/linuxone

• sign in

Create an SSH key pair:

• Virtual Servers tab

• open personal menu and manage SSH key pairs

• if you already have a key, import it, if not, create and save one (.pem file)

• Create

Create a virtual server:

• instance name has no spaces or special characters

• RHEL with the highest version number (RedHat Enterprise Linux; other systems can be tried as well for fun)

• select SSH key pair

• Create

• VM status phases: networking, spawning, active

Get full Windows username in Powershell:

• start up Powershell

• whoami

Get full path to .pem key pair:

• Resolve-Path "path/to/.pem"

Note names:

• vmServerIPAddress: look for it in the line of the virtual server

• vmUsername: linux1

• fullWindowsUserName: what the whoami shows

• keyFileFullPath: the path what the Resolve-Path showed

Manage SSH key in Powershell:

• icacls "keyFileFullPath" /reset

• icacls "keyFileFullPath" /inheritance:r

• icacls "keyFileFullPath" /grant:r "fullWindowsUserName:(R)"

Check rights on the SSH key pair:

• the user must fit to fullWindowsUserName with R right: icacls "keyFileFullPath"

• the key must be readable and starting with -----BEGIN RSA PRIVATE KEY-----: type "path\to\your-key-file.pem"

Connect to VM:

• ssh -i "keyFileFullPath" linux1@vmServerIPAddress

Install nano small-text editor:

• sudo yum install nano

Setup prompt (works on VM-level):

• nano ~/.bashrc

• modify or add new line: PS1="\e[92m\n\w>\e[0m "

• save

• exit nano

• source ~/.bashrc

Setup compiler environment for C source files:

• software builder from a configuration file: sudo yum install make

• GNU C compiler: sudo yum install gcc

2. COMMANDS

Most of the available commands are coming the UNIX ancestry therefore there are many similarities with the USS.

The Linux1 user reaches over the system, not just the home directory, but it is a non-root user (not an administrator).

Special codes in prompt pattern (escaped characters):

• \u: username

• \h: hostname

• \H: full hostname

• \w: full path

• \W: working directory name

• \t: actual time

• \T: 12-hour time

• \d: actual date

• \!: number of command in history

• \$: $ for normal user, # for root

• \n: new line

• \e[sxm: s: colour series number, x color number

• \e[0m: reset color

Colour series codes:

• 3:basic, dark

• 4: background

• 9: bright

Colour codes:

• 1: red

• 2: green

• 3: white

• 4: blue

• 5: black

• 6: turquise

• 7: gray

Default prompt:

• [\e[0m\u@\h \W]\$

3. DIRECTORIES

In root:

• bin: programs, binaries

• etc: system-wide configuration files

• home: user directories, e.g. /home/linux1

• lib: shared code and kernel libraries

• root: sysadmin files

• usr: shared, read-only files

• var: changing file e.g. logs, printer spools, caches

4. APACHE

Install web server program:

• yum search apache

• sudo yum install httpd.s390x

Start Apache web server:

• start: sudo apachectl start

• set autostart: sudo systemctl enable httpd

• show status: sudo apachectl status

Create homepage:

• cd /var/www/html 

• sudo nano index.html

• fill the content

• save, exit

• ip addr

• note enc1000/inet

Check firewall:

• sudo iptables --list

Open port 80:

• sudo iptables --insert INPUT --protocol tcp --dport 80 --jump ACCEPT

Check firewall:

• sudo iptables --list

• new ACCEPT line must be visible (tcp dpt:http, dpt = destination port)

Check homepage:

• launch a browser

• http://148.100.112.97

Check tcp log:

• sudo tail -f /var/log/httpd/access_log

• ^C

5. DOWNLOAD, UNPACK, EDIT, COMPILE, RUN

EXAMPLE FOR UTILIZING AN OPEN SOURCE TETRIS:

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