Add server OS documentation

Author: duvallj

SUMMARY.md

@@ -120,6 +120,7 @@
     * [QEMU](technologies/virtualization-stack/qemu.md)
     * [KVM](technologies/virtualization-stack/kvm.md)
     * [Libvirt](technologies/virtualization-stack/libvirt.md)
+  * [Netboot](technologies/netboot.md)
   * [Advanced Computing](technologies/advanced-computing/README.md)
     * [MPI](technologies/advanced-computing/mpi.md)
     * [Tensorflow](technologies/advanced-computing/tensorflow.md)
@@ -232,4 +233,3 @@
 * [Policies](policies/README.md)
   * [Data Release Policy](policies/data-release-policy.md)
   * [Upgrade Policy](policies/upgrade-policy.md)
-

technologies/netboot.md

@@ -0,0 +1,3 @@
+# Netboot
+
+<https://netboot.xyz/>

technologies/servers/README.md

@@ -1,4 +1,13 @@
 # Servers
 
+The CSL currently runs two separate operating systems on its servers:
 
+{% page-ref page="./ubuntu/" %}
 
+{% page-ref page="./centos/" %}
+
+The CSL used to run a multitude of other operating systems, mostly on Sun hardware. These included:
+* (Sun) Solaris
+* Gentoo
+* FreeBSD/OpenBSD
+* Whatever the [Cray SV1 ran](../../machines/obsolete/cray-sv1-supercomputer.md)

technologies/servers/centos.md

@@ -1,4 +1,19 @@
 # CentOS
 
+[CentOS](https://www.centos.org/) is a stable Linux distribution derived from the sources of the popular [RedHat Enterprise Linux](https://www.redhat.com/en/technologies/linux-platforms/enterprise-linux).
 
+The CSL only has a few servers running on CentOS; namely, [The Cluster](../../cluster/README.md). The rest run on [Ubuntu Server](./ubuntu-server.md).
 
+## Notable Features
+
+* Slightly higher stability than Ubuntu
+* Has a different package manager (`yum` + `rpm`)
+* Slightly smaller package ecosystem, made up for by large 3rd party repositories.
+
+## Notable CSL Modifications
+* We use [Netboot](../netboot.md) to install it
+
+## Trivia
+* All of the system configuration and log files are named slightly differently than Ubuntu, making things slightly annoying.
+* CentOS actually beats out Ubuntu in how old its Python is; there is no Python 3, only Python 2.7.5 in the official repository!
+* You can pry my CentOS-specific Ansible plays from my cold, graduated hands.

technologies/servers/ubuntu-server.md

@@ -1,4 +1,28 @@
 # Ubuntu Server
 
+Ubuntu Server is a Linux distribution developed by Canonical Inc., noted for its stability and ease of use. You can find out more on [the Ubuntu Wiki](https://wiki.ubuntu.com/BionicBeaver/ReleaseNotes).
 
+Almost all of the CSL runs on Ubuntu Server, except for [Workstations](../../services/workstations/README.md) (which run Ubuntu Desktop) and [The Cluster](../../cluster/README.md) (which runs [CentOS](./centos.md)).
 
+## Notable Features
+
+* Easy-to-use installer ISO (download link [here](https://www.ubuntu.com/download/server)
+* Extremely large, if not *the* largest, package ecosystem
+* Has included some unpopular software, including (but not limited to):
+  1. The Unity desktop environment
+  2. Integrated advertising
+  3. netplan
+
+## Notable CSL modifications
+
+* Instead of installing from a usb, we prefer to use [Netboot](../netboot.md)
+
+## Trivia
+* Ubuntu gets a significant portion of its packages from Debian, and shares the same package manager (`apt`).
+* One of Ubuntu's offical help channels is actually found on [StackExchange](https://askubuntu.com/).
+* Ubuntu major releases are referred to by alliterating `<adjective> <animal>` codenames. As of this writing (Jan 2019), the current stable release (18.04.1) is codenamed **Bionic Beaver**.
+* The default version of Python is 2 on all Ubuntu releases.
+  * Plus, the minor version of Python 3 available is always 1  behind the latest.
+* `nano`, arguably the superior console text editor, is installed by default (as it should be).
+* Netplan can act as a configuration proxy for NetworkManager, in case you ever wanted to double the amount of cancer you handle.
+* 16.04.5 LTS (**Xenial Xerus**) will always be the best release in my heart <3