subscription-manager unregister
subscription-manager clean
subscription-manager register
subscription-manager subscribe --auto

subscription-manager identity
subscription-manager list --consumed
subscription-manager list --available
subscription-manager repos --list
subscription-manager repos --refresh

subscription-manager repos --enable=repoid
subscription-manager repos --disable=repoid

systemd-nspawn - starts a namespace/chroot container environment (A Docker like environment)

1. Create a directory you want to install your container into
	mkdir /opt/DebianJessie
2. debootstrap --arch=amd64 stable /opt/DebianJessie - installs DebianJessie
3. systemd-nspawn -D opt/DebianJessie - start the container as root
	Add a b in front of the D = -bD to start the container without root

Fedora Eg.: dnf --releasever=24 --installroot=/absolute/path/ install systemd passwd dnf fedora-release - to install Fedora

loadmpi.sh 
#!/bin/bash
module load mpi
export PYTHONPATH=:/usr/lib64/python2.7/site-packages/openmpi:/usr/lib64/python2.7/site-packages/openmpi:/usr/lib64/python2.7/site-packages/openmpi
python -c "import mpi4py"

Purpose
    Connect to the company Citrix environment through Citrix Receiver on Fedora/RHEL/Centos
Process

(1) Download the latest rpm receiver web package from Citrix: https://www.citrix.com/downloads/citrix-receiver/linux/receiver-for-linux-latest.html
(2) Open a terminal windows and goto your Downloads directory: ~/Downloads
(3) Type example: sudo rpm -ivh ICAClientWeb-rhel-13.10.0.20-0.x86_64.rpm

Since our certificate comes from GoDaddy citrix receiver is not aware of our companies certificate 

(4) Type the following: sudo vi /opt/Citrix/ICAClient/keystore/cacerts/\ Trust_Go\ Daddy\ Root\ Certificate\ Authority\ -\ G2
(5) Enter your password if needed
(6) Press i - in vi
(7) Copy and paste the following:
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----
(8) Select: ESC
(9) Type: :wq - Press Enhttps://www.citrix.com/downloads/citrix-receiver/linux/receiver-for-linux-latest.htmlter
(10) In a web browser goto https://citrix.companyname.com
(11) Login
(12) Select your application option - You should be prompted to open the ica file. Open with "Citrix Receiver Engine"
(13) If you do not want to be continually prompted select - "Do this automatically for files like this from now on."
(14) Click OK
(15) If you were already in the browser you are using you may have to close out and restart it.

When setting up Fedora 28 for enterprise login on installation there is a bug goes not allow root access for your enterprise user. As a result there is no way to sudo or su with out doing the following fix:

Open a shell in initrd, mount /sysroot as read-write and edit /sysroot/etc/group

Steps:
1. Reboot
2. In grub press "e" to edit the menu entry
3. Search for a line that starts either with linux16 or linuxefi and append the string " rd.break"
4. Press ctrl+x
5. Mount the /sysroot as read-write: mount -oremount,rw /sysroot
6. Open /sysroot/etc/group in a text editor
7. search for the line "wheel:x:10:" and append your user
8. You may run into selinux issues, so either set it to permissive (edit /sysroot/etc/selinux/config) or touch /sysroot/.autorelabel
9. reboot again
10. If in step 8 you set selinux to permissive, restorecon /etc/group and reset selinux back to enforcing and reboot again.