gnome


Install Gnome Boxes on Kali Linux

Our solution in getting Gnome Boxes to work on Kali Linux (which is a Debian-derived Linux distribution just like Ubuntu) is the following:

First install Gnome Boxes along with all needed virtualization software:

sudo apt-get install -y gnome-boxes qemu-kvm libvirt0 virt-manager bridge-utils;

Then, edit the file /etc/libvirt/qemu.conf to uncomment the following line:

#user = "root"

Finally, restart the host machine and your Gnome Boxes will be ready to use.

Long story

Recently, we were setting up a Kali Linux machine and one of the requirements was to add virtualization support so that the user could execute virtual machines doing.. other stuff. We started by installing gnome-boxes only (hoping that would be enough)

sudo apt-get install -y gnome-boxes;

.. but we got an error:

Boxes cannot access the virtualization backend

Apparently, installing gnome-boxes only, the dependency system did not automatically assume we would need to install an engine to handle the virtual machines, so we had to install the following as well:

sudo apt-get install -y qemu-kvm libvirt0 virt-manager bridge-utils;

After the installation, we tried  to create a new virtual machine but it would fail when we tried to start it. After looking into the logs we found the following useful information:

State: GVIR_DOMAIN_STATE_SHUTOFF

It seems that our user (even if it was root) could not start the QEMU process. To fix this issue we had to modify the file /etc/libvirt/qemu.conf and uncomment the following line:

#user = "root"

from this section

# The user for QEMU processes run by the system instance. It can be
# specified as a user name or as a user id. The qemu driver will try to
# parse this value first as a name and then, if the name doesn't exist,
# as a user id.
#
# Since a sequence of digits is a valid user name, a leading plus sign
# can be used to ensure that a user id will not be interpreted as a user
# name.
#
# Some examples of valid values are:
#
# user = "qemu" # A user named "qemu"
# user = "+0" # Super user (uid=0)
# user = "100" # A user named "100" or a user with uid=100
#
#user = "root"

# The group for QEMU processes run by the system instance. It can be
# specified in a similar way to user.
#group = "root"

After doing this change and restarting the host machine we were able to start and use any virtual machine in Gnome Boxes.

Extra information

In this case, we were using Kali Linux, where people usually operate it using the root account only.
On other installations, like on an Ubuntu installation you would need to handle differently the last step that requires you to edit the /etc/libvirt/qemu.conf file.

Specifically, the best way to handle this issue on a multi-user environment (like Ubuntu) would be to replace the following line:

#group = "root"

with this

group = "kvm"

and then add yourself to the kvm group before restarting the host machine

sudo usermod -a -G kvm $USER;

Doing so, it allows you to enable access to the virtualization services to multiple users of you choice instead of limiting it to one account.

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Fedora 25 with GNOME 3: Making a Wi-Fi hotspot 7

Recently we tried to create a Wi-Fi hotspot on Fedora 25 running GNOME 3.

When we clicked on the Use as Hotspot... button  on the network manager it did not activate the hotspot.
Actually, nothing changed after we clicked on the button.
We tried this several times, some while being disconnected from all networks, others with having the Wi-Fi device disabled etc. None of the tests payed out.

To mitigate the problem, we used nm-connection-editor to create the hotspot configuration and then activate it from the network manager.

After we starter nm-connection-editor, we pressed the Add button to create a new configuration:

From the prompt, we selected the option Wi-Fi and then clicked on the Create... button.

In the newly appeared window, we filled in

  • the Connection name (which is not used by the system, it is only for us to identify which configuration this is),
  • then the SSID (which is the name of the network you will create and connect to),
  • we set Mode to Hotspot

Then we switched to the Wi-Fi Security tab where we filled in the type of protection we want the hotspot to have and the password for it.

We clicked Save and then we closed the Network Connections window as well.

From the network manager, we clicked on Use as Hotspot... button and then the Turn On button on the confirmation popup to finish the activation.

After this, the network manager changed its screen and showed a page which had all the necessary information that are needed to connect to our newly created hotspot.

Note:

In case you cannot connect because the password verification fails even though you are providing the correct password, you can always do the ugly hack of setting up a hotspot with no security to get your job done…


A couple of notes on moving a VirtualBox ‘.vdi’ disk image to a GNOME Boxes virtual machine

Recently we had a CentOS virtual machine on VirtualBox which we wanted to use in GNOME Boxes.
We copied the .vdi disk image and we used it to create a new virtual machine in Boxes.

Note A:

By doing this we realized that the system did not reuse the .vdi image.
It merely created a copy at ~/.local/share/gnome-boxes/images/ that was suitable for GNOME Boxes.
So, be sure to have enough space when doing an import like this.
You will need at least twice the space of the .vdi image to complete the migration.

Note B:

When the guest OS started the window manager crashed and it did not allow us to login.
We assumed that this issue occurred due to the VirtualBox Guest Additions that were installed on the guest OS.
As we could not login with the graphical interface, we could not verify this claim.

Fortunately, CentOS (and many other Linux distributions) allow you to switch to a console login using the key combination alt + ctrl + F3.
(There are more than one valid key combinations to do this. In some systems alt + ctrl + F4 is also valid or alt + ctrl + F1 etc).
We hoped that by trying to login via a console login, the Guest Additions would not start and the system would not crash, which luckily this was the case, and we managed to login through the console!

After we logged in, we had to remove the Guest additions. To do so we had to execute the uninstall script that was located at /opt/VBoxGuestAdditions-X.Y.Z/uninstall.sh
(X.Y.Z is the version number of the installed VirtualBox Guest Additions).

When the removal was complete, we executed sudo reboot to restart the system and unload any VirtualBox services that could be executing at the time.
Once the system completed the restart we were able to login properly from the GUI of GNOME and use our virtual machine properly.


Gnome3: How to scale background image 2

Issue in your terminal the following to change the mode of how the background is displayed

gsettings set org.gnome.desktop.background picture-options "scaled"

We used “scaled” which will center the image to and will resize it to fit the screen if needed.
You could use another option if you like. To get the full list of available options issue the following in your terminal.

gsettings range org.gnome.desktop.background picture-options

It will produce a list similar to this

enum

  • ‘none’
  • ‘wallpaper’
  • ‘centered’
  • ‘scaled’
  • ‘stretched’
  • ‘zoom’
  • ‘spanned’

To reset to the default option use the following

gsettings reset org.gnome.desktop.background picture-options