Sahara

This page describes how to install and configure the Sahara virtual machine for use in this class.

Installing VMware

Some of what we'll be doing involves making system-wide changes, so you'll need a Linux system to experiment on. The best way to do this is to use a virtual machine. Roughly, the procedure is as follows:

Install virtual machine management software on your computer.
Using the management software, define a virtual machine (VM). This means selecting how much memory and disk space you want to allocate to your VM, as well as perhaps other settings.
Install a "guest" operating system into your VM.
Using the management software, boot your VM and interact with it as if it were a regular computer.

The beauty of using virtual machines is that you can install various guest operating systems into multiple VMs and experiment with them, all in the context of your regular system. You don't need to locate any additional physical hardware, nor do you need to repartition your system to "dual-boot" it.

Most virtual machine management software also allows you to create "snapshots" of your VM that you can easily restore if something goes wrong. This enables the following workflow:

Take a snapshot of your VM.
Attempt a complex and challenging configuration task.
If successful, you can delete the snapshot (or not). If the task fails, you can restore the snapshot and undo the effects of your broken reconfiguration attempt.

For this course, I recommend using VMware Workstation Pro (the latest version is 17.6.3 at the time of this writing). If you are a Mac user, you will want to use the related product called VMware Fusion.

The official way to get the installer for VMware is to go to the URL: https://www.vmware.com/products/desktop-hypervisor/workstation-and-fusion. You will find a button on the page that says, "Download Fusion or Workstation." This will bring you to a Broadcom login page. Broadcom recently purchased VMware. You will need to make a (free) account with Broadcom. Click on the link that says, "Free Software Downloads." Scroll to the bottom where the VMware products can be found and select Workstation Pro (for Windows) or Fusion (for macOS). To download, you need to accept the terms and conditions, but you need to view them before you can accept them.

As a convenience I put the Windows installer here.

Note that VMware Workstation/Fusion were commercial products. However, Broadcom makes them available under a personal use license that allows you to install them on your machines and use them how you like, provided you aren't being paid for what you are doing with them.

Setting up the Sahara VM

Proceed as follows:

Go to the Ubuntu Downloads page and select a suitable ISO file for the version of Ubuntu you want to use. We will be using the "server" version. If you are running on an Apple M-series processor, you will need to download the ARM64 version, otherwise download the x86_64 version.
Start VMware and select "Create a New Virtual Machine." Select the "typical" configuration type. Specify the ISO file you downloaded when prompted about the "installer disc."
Specify the name "Sahara" for the virtual machine, but otherwise accept the other defaults.
During the installation of Ubuntu, you can accept the defaults except you should uncheck the box saying to set up the disk as an LVM group. We won't be using LVM in this course. It would be helpful to take note of the IP address used for the system during installation. You will need that address later.
Be sure to install the OpenSSH server but do not install any other software packages at this time.
When the installation compiles, let the system reboot inside the virtual machine. You should see it come up with a login prompt on the console containing the host's name (sahara, assuming that is what you used).

Connecting to Sahara

Start your favorite SSH client and set up a session using the IP address for the virtual machine (hopefully, you noticed it during the installation above). You should be able to log into the VM via your SSH client.

This is a nicer way to interact with the VM than logging in directly to the console. The console interface is fairly primitive. Your SSH client is likely much more comfortable (and if it's not, you should investigate a better SSH client).
Execute the following commands in Sahara to bring it fully up to date:
```
$ sudo apt update
$ sudo apt upgrade
$ sudo apt autoremove
```
Execute the following command to reboot Sahara once the updates have been applied:
```
$ sudo shutdown -r now
```
This command shuts the system down with reboot (-r) right away ("now").
Once you are convinced the system is running normally, you can shut it off using the command:
```
$ sudo shutdown -h now
```
Here the -h option means "halt."