Building a VM suitable for distribution to a class on a USB drive

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I am teaching a class to first and second year undergrads. Since we will be using many different types of software I was discouraged by the idea of installing all of the software they would need on all of their computers. Although installing software is a very useful exercise, the many different platforms and laptops make this task prohibitively hard to manage.

In the past I have used "Portable Apps" to deliver software to windows users. This works great and eliminates the need to install a lot of software. However, typical portable apps do not work on macs and more than half of my class use macs.

So, my next thought was to use a lightweight Virtual Machine (VM). I had some supply funds for the students so I bought them all 16GB USB drives and my plan is to install the VM on the drives and use the drives to also pass around the data files the students need for their projects. I would just put all the data files on the VM but each student needs a different set of files and they would make the VM much bigger than the 16GB that I had available.

My plan is to create a USB drive with a standard Virtual Machine Image and then Individual project data for each student. Here is the process I went though to make these drives:

Choosing a VM platform and building the machine:

I created a Lubuntu VM using VMWare and installed all of the software I wanted the students to have. This included; Python (with a lot of packages), ImageJ, FFmpeg and others. Then I found out that VMWare Player doesn’t run on a mac so I had to switch to VirtualBox. I used the following instructions to convert the VM:

http://www.ubuntugeek.com/howto-convert-vmware-image-to-virtualbox-image.html

Take away : Use VirtualBox, it works the best cross platform and is available for free

Copy the VM to the USB drive (first attempt):

Once I had a working VM I copied over the file to the USB drive and tried to run it. Unfortunately, trying to boot the VM gave me all types of errors and I ended up realizing that the USB drives are formatted using FAT32 and can not contain files larger than 2gb

Take away : Can't use FAT32 to save large VM drive files

Reformat and copy the VM to the USB drive (second attempt):

So, I did some research and both mac and windows support exFAT a new files system from Microsoft specifically designed for larger files on USB drives. Great! I formatted the USB drive to use exFAT, copied over the VM and then individually copied the data files each student needed onto their USB drive.

Problem 1: exFAT drive formatted on a MAC

When I passed the drives out in class today they would not be recognized by the windows machine. It seems that exFAT only works in one direction. When I format the drive on my MAC and try to read it on windows it doesn’t work. However, if I format exFAT on windows my MAC can read it fine.

Problem 2: Missing Linux USB Drivers

Another problem I did not consider is that the exFAT drive can not be recognized in the Lubuntu VM. So, although the VM worked fine on the MACs, the students could not read their data.

Fix limitations of exFAT (third attempt):

We did some brainstorming and came up with the following possible solutions that cover both problems:

Option 1. Format exFAT on windows machines (so they will work on both MAC and windows). Figure out how to install exFAT drivers in Lubuntu.

This option ended up not being too difficult. I used the following commands to install exFAT on the Lubuntu machine:

sudo apt-add-repository ppa:relan/exFAT
sudo apt-get update
sudo apt-get install fuse-exFAT exFAT-utils

Option 2. Duel partition the USB drive with one exFAT drive (Formatted on windows) and one FAT32 drive for the data.

Seems like a lot of work and I would need to switch to the disk duplicate tool (dd) to make the copies.

Option 3. Format the entire drive back to FAT32 and break the VM down into smaller files.

I can't find a way to break the large files apart in Virtual box. I could do it with some third party splitting software but then I would need to figure out how to merge the files on each individual computer. Not really a step I prefer to take.

The VMDK files in VMWear are already broken up into 2gb or less files. I may be able to convert back to the VMDK files and load the VM in Virtual box directly.

Option 4. Try a different large-scale file system such as NTSF and get that to work on all of the platforms.

I was told that this could be tricky especially if the students to not properly eject their USB drives. So far I have avoided this option.

Final Take Aways : Option 1 worked for me. Use VirtualBox and an exFAT formatted USB drive. Make sure the exFAT drive is formatted in Windows and install exFAT drivers on your Linux VM before distribution.

- Dirk

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