WhiteWinterWolf Practical IT security, *nix systems & networking

This the first of a short series of posts introducing vmtools main features. We will start in a gentle way by focusing on a single but central command: vmup.

Feel free to contact me if anything seems unclear or would warrant more explanation.

vmtools installation and uninstallation

Use the provided install.sh script to install vmtools on your system. The default is to install it system-wide:

sudo sh ./install.sh

To install it as unprivileged user, create a ~/.local directory and use it as installation prefix:

sh ./install.sh -p ~/.local

To uninstall vmtools, use the provided uninstall.sh script.

Centralized configuration file

System-wide settings are stored in the file /etc/vmtools/vmtools.conf, this file is optional and must be manually created.

This file lets you centrally configure the default settings to apply to all your virtual machines.

Here is an example file:

# Use VNC as the default display output:
vm_display_type=vnc

# Set the default keyboard mapping to use:
vm_keyboard_mapping=fr

See vmtools.conf(5) for more information.

Use vmup to boot a disk image

Simply pass a file of a URL as argument to vmup to boot it.

Here we are booting from a remote .iso file:

user@host:~$ vmup "http://tinycorelinux.net/7.x/x86/release/TinyCore-current.iso"
-----------------------------------------------------------------
Answer to the questions below to define the guest properties.
You can type '?' to display the help screen at any time.
-----------------------------------------------------------------

Number of vCPUs (default: 2)?

RAM size (default: 2G)?
TinyCore-current.iso: Virtual machine started.
user@host:~$

The configuration questions are handled by the enabled plugins. The virtual machine creation and startup process can be completely revamped by defining your own plugins.

Third-party and legacy image formats are also supported (including .ova images¹ not natively supported by Qemu). vmtools proposes to automatically convert such images:

user@host:~$ vmup turnkey-lamp-14.2-jessie-amd64.ova
-----------------------------------------------------------------
Answer to the questions below to define the guest properties.
You can type '?' to display the help screen at any time.
-----------------------------------------------------------------

Number of vCPUs (default: 2)?

RAM size (default: 2G)?

Auto-conversion: /home/user/turnkey-lamp-14.2-jessie-amd64.ova
This file seems to be either a third-party or a legacy file, it is recommended to
convert it for regular usage.
Create a Qcow2 copy of this file [yN]? y
    (100.00/100%)
turnkey-lamp-14.2-jessie-amd64.ova: Virtual machine started.
user@host:~$

Main vmup options

-y: bypass interactive questions

Most vmtools commands propose a -y (think “yes”) flag to silently bypass all interactive questions:

user@host:~$ vmup -y tails-amd64-3.1.iso
tails-amd64-3.1.iso: Virtual machine started.
user@host:~$

-c, -d: Add virtual disk devices

Use the option:

• -c path to add a supplementary virtual hard-disk drive to the guest.
• -d path to add a supplementary CD/DVD ROM drive.

Think of Windows’ traditional C: and D: drives³ to remember the option letters.

These options can take either a path to an image file or to a directory as parameter, the latter case is a convenient way to pass files from the host system to the guest (and is pretty unique to vmtools AFAIK):

user@host:~$ vmup -d ./WSUS_Offline/ ./Windows-7-pro_amd64.qcow2
-----------------------------------------------------------------
Answer to the questions below to define the guest properties.
You can type '?' to display the help screen at any time.
-----------------------------------------------------------------

Number of vCPUs (default: 2)?

RAM size (default: 2G)?
Windows-7-pro_amd64.qcow2: Virtual machine started.
user@host:~$

The command above starts the Windows-7-pro_amd64.qcow2 hard-disk image while making the content of the WSUS_Offline directory (most probably a set of offline Windows updates) available to the guest as a virtual CD/DVD ROM reader.

-s: Enable snapshot (non-persistent) mode

-s allows to start a virtual machine in snapshot (non-persistent) mode:

user@host:~$ vmup -s -c ./hdd.raw ./kali-linux-2016.1-amd64.iso
-----------------------------------------------------------------
Answer to the questions below to define the guest properties.
You can type '?' to display the help screen at any time.
-----------------------------------------------------------------

Number of vCPUs (default: 2)?

RAM size (default: 2G)?
kali-linux-2016.1-amd64.iso: Virtual machine started.
user@host:~$

In the example above, the following parameters have been used:

• -s: Access all hard-disk image files in snapshot mode, disk image files will not be modified⁴.

  A similar result can be obtained by prefixing hard-disk image paths with the snap: prefix or by removing the write permission (chmod a-w ./hdd.raw) on the image files.

• -c hdd.raw: Add a supplementary hard-disk image to the virtual machine.

• ./kali-linux-2016.1-amd64.iso: The local .iso image to boot, as seen in the previous examples.

Here the user boots Kali Linux with a read-only raw hard-disk disk image, possibly to do some forensic analysis on a disk dump.

Conclusion

You should now be able to use vmup to boot disk image files more conveniently.

This post covered only the most common options and use-cases. The complete list of vmup options is available through vmup -h and on vmup(1) man page.

While this is a useful feature in itself, and might even be enough for some users, vmtools is able to do far more but this will be discussed in the second part of this guided tour.