DADA: HW 1: Virtual Machine

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Introduction

VirtualBox is a free program that allows you to run another operating system on your machine without needing to reinstall anything. You have to install the VirtualBox client, which installs like any other program and is available for many different platforms (Windows, Mac, Linux). We provide you with a pre-configured VirtualBox image that contains an Ubuntu Linux installation that you can use for this course.

The homework part of this is at the end of this document.

Parts of this document were inspired by, or copied with permission from, a similar homework by Charles Reiss (original was here).

Quick start

• A bit of terminology: the ‘host’ machine is the physical computer (laptop, desktop, etc.) that you are using. The ‘guest’ machine is the virtual machine that is running in VirtualBox, and is often just called the ‘guest operating system’.
  • You are welcome to try this on a netbook host machine, but the computing power of a netbook may not be enough
• Ensure your computer has VT-x support enabled (see below)
• You will need to install the Virtual Box client. It can be downloaded for free from here. Download the latest version.
• Download the provided VirtualBox image (given out in class). You will need to unzip this file before using it.
  • This file is rather large (about 2.6 Gb), so you may want to try downloading it during off hours, such as late at night. If you have problems downloading it, let us know. If you do not have sufficient bandwidth to download it, please see us after lecture, and we will provide it on a different media for you.
  • Unzip this file; it will take up about 8 Gb on your machine. Once uncompressed, you can download the .zip file that you downloaded.
    • Your unzip program may complain about needing some insane amount of space (like 700 petabytes, where a petabyte is 1,000 terabytes); this is a bug in many unzip programs. Try 7-zip, which has had more success.
• Run VirtualBox, and import the image:
  • To do that, click on ‘New’, and choose the right OS/version (“Ubuntu (64 bit)” – don’t choose the 32 bit version!). Give it a name to help differentiate it from other virtual machines that you may end up using in other classes.
  • Increase the default memory – 2 Gb is reasonable. But if your computer doesn’t have as much, then consider a lower amount.
  • At the ‘Hard drive’ screen select ‘use an existing virtual hard drive file’, and click the folder icon to the right of the drop-down list. You want to use the file you unzipped above.
  • That should be it for the Wizard
• Boot the machine (click the Start icon at the top - it’s a green rightward pointing arrow). You may notice some display artifacts during boot-up as the virtual machine changes video modes, but that will stabilize once booting has completed.
• The login is ‘student’ (although you’ll probably click on the ‘L33t Hax0r’ button on the login screen), and the password is ‘password’. You can click on the command-prompt icon on the bottom toolbar to get a terminal window.
  • The documentation is available online in either HTML format or PDF format, although most of the salient details are listed on this page.

Notes

• No root password is set (you can use sudo instead); to change the root password, run sudo passwd.
• The ‘host key’ is defined by your host machine’s operating system (it’s the right control button under Linux, for example). This key is used for a number of contexts, including un-capturing the mouse. To have VirtualBox warn you about what the host key is, you can reset all warnings via the VirtualBox help menu, and it will warn you about this at boot-up. It may also be listed in the lower-right of the VirtualBox window.
• We did not install the latest version of Ubuntu, but instead installed the Long-Term Support (LTS) version, which is 16.04. The difference is that the LTS versions are supported for far longer (3 years or so) than the non-LTS versions (which are only supported for a year or so). For this class, there won’t be a noticeable difference between 16.04 and more recent versions.
• Sound and network should work automatically, as the VirtualBox program will connect those to your host machine’s sound and network device drivers.

VT-x support

For 64-bit VMs, VirtualBox requires some hardware support from your processor. This support is present on almost all processors made recently (including all laptop or desktop processors introduced by Intel since 2013). However, some computer manufacturers disable this support by default. When they do this, you can usually re-enable the feature in BIOS or “the Setup Utility”.

How you access the BIOS/Setup varies between manufacturers. Common ways include pressing Enter or F2 or F12 or Del while booting the machine. If you are using Windows 10, you may need to first shut down the machine while holding shift - some Windows 10 installations default to not performing a “complete” shut down. You should be able to look up full instructions online for accessing BIOS/Setup based on the model of your laptop or desktop.

Once in the Setup utility, the option to change is likely to be called something like “Intel VT-x”, “Intel Virtualization Technology”, “virtualization technology”, or “AMD-v”. Confusingly, this setting is sometimes under category called “Security” instead of something more obvious. After changing it, save the settings and reboot.

If you have trouble setting getting 64-bit VMs to work on your machine, please do not hesitate to contact the course staff for assistance.

In the unlikely event that you have a laptop that does not support running 64-bit VMs with VirtualBox, we will make alternate arrangements such as making the assignments only use 32-bit, or finding a way for you to do the assignments by remote logging into lab machines.

How-Tos

• To load a terminal (a.k.a. command prompt): it’s towards the bottom of the menu on the left-hand launcher column.
• To load emacs: it’s also in the menu on the left-hand launcher column, right above the terminal launcher icon
• To change the password: when logged in, you enter the ‘passwd’ command from a terminal window. You should do this. The original password is ‘password’.
• To toggle between full-screen and windowed mode, click on the host key and ‘f’. Don’t know what the host key is? Read the bullet point about this in the ‘Notes’ section, above.
• To change the screen resolution: from the top menu bar, click on the circular power button icon on the far right, and select ‘Displays’. Note that there are not many resolutions available, but you can use full-screen mode which will change the resolution to your host machine’s resolution.
• To set up printing: it’s probably easiest to print to a PDF, transfer that file to your host machine (see below), and print from your host machine.
• Load up a file manager (like Windows Explorer): from the ‘Places’ menu (upper-left of the screen), select ‘Home Folder’
• Make emacs show one screen (and not be a split-screen): press control-x then press ‘1’ (this should not be necessary, by the way)

Transferring files back and forth

A few options:

• You can use an e-mail client or use a web browser and e-mail your files back and forth. Or use an online file server.
• If you are using a github repository, then that will “save” your files and allow transfer back and forth.
• You can set up ‘shared folders’ to directly read and write files back and forth. To do so, see here.
• Dropbox may be the easiest way to sync files between your virtual machine and your host machine. To install:
  • download the 32-bit Ubuntu version downloaded from here - be sure to save the file, not open it, from Firefox
  • install it from the command-line via ‘sudo dpkg -i dropbox_1.4.0_i386.deb’ but note that the file name may change as a new version is released
    • note: dropbox requires a supporting package (python-gpgme), but I already installed that on the image
  • once installed, a vibrating icon will appear in the left-hand launcher; click on that, then click on “Start Dropbox”
  • this will download the proprietary daemon (a daemon is a background process) and install it
  • at that point, the standard dropbox registration wizard will appear

Image creation details

Here (md) are the details of how the image was created.

C exercise

• Open a terminal window.
• Open a text editor, such as gedit or emacs, and create a file called hello_world.c in your home directory containing the following:

    #include <stdio.h>
    int main(int argc, char **argv) {
        printf("Hello world! I am a Wizard in Training.\n");
        return 0;
    }

• Run clear command to clear the terminal
• Compile the C source file you created with for 64-bit with gcc -o hello64 hello_world.c
• Run this file and to make sure it works with ./hello64
• Compile the C source file you created with for 32-bit with gcc -m32 -o hello32 hello_world.c
• Run this file and to make sure it works with ./hello32
• Run the command uname -a
• Take a screen shot of your terminal window. Name it hw1.png or hw1.jpg. There are several options for doing this:
  • Research, for example with web search, how to do this in your host OS
  • Take screen shot in the VM’s OS using gnome-screenshot -i
  • Research an alternate way to take a screen shot in your host OS
• Submit the screen shot via Collab as your submission for this assignment.

Items to submit

Just the screen shot taken as the last step of the above section. To make it viable for us to grade, please name it hw1.png or hw1.jpg (but make sure that the file type matches the extension).