Technology Tales

Changing the UUID of a VirtualBox Virtual Disk Image in Linux

Recent experimentation centring around getting my hands on a test version of Windows 11 had me duplicating virtual machines and virtual disk images though VirtualBox still is not ready for the next Windows version; it has no TPM capability at the moment. Nevertheless, I was able to get something after a fresh installation that removed whatever files were on the disk image. That meant that I needed to mount the old version to get at those files again.

Renaming partially helped with this but what I really needed to do was change the UUID so VirtualBox would not report a collision between two disk images with the same UUID. To avoid this, the UUID of one of the disk images had to be changed and a command like the following was used to accomplish this:

VBoxManage internalcommands sethduuid [Virtual Disk Image Name].vdi

Because I was doing this on Linux Mint, I could call VBoxManage without need to tell the system where it was as would be the case in Windows. Otherwise, it is the sethduuid portion that changes the UUID as required. Another way around this is to clone the VDI file using the following command but I had not realised that at the time:

VBoxManage clonevdi [old virtual disk image].vdi [new virtual disk image].vdi

It seems that there can be more than way to do things in VirtualBox at times so the second way will remain on reference for the future.

Getting rid of the Windows Resizing message from a Manjaro VirtualBox guest

Like Fedora, Manjaro also installs a package for VirtualBox Guest Additions when you install the Linux distro in a VirtualBox virtual machine. However, it does have certain expectations when doing this. On many systems and my own is one of these, Linux guests are forced to use the VMSVGA virtual graphics controller while Windows guests are allowed to use the VBoxSVGA one. It is the latter that Manjaro expects so you get a message like the following appearing when the desktop environment has loaded:

Windows Resizing
Set your VirtualBox Graphics Controller to enable windows resizing

After ensuring that gcc, make, perl and kernel headers are installed, I usually install VirtualBox Guest Additions myself from the included ISO image and so I did the same with Manjaro. Doing that and restarting the virtual machine got me extra functionality like screen resizing and being able to copy and paste between the VM and elsewhere after choosing the Bidirectional setting in the menus under Devices > Shared Clipboard.

That still left an unwanted message popping up on startup. To get rid of that, I just needed to remove /etc/xdg/autostart/mhwd-vmsvga-alert.desktop. It can be deleted but I just moved it somewhere else and a restart proved that the message was gone as needed. Now everything is working as I wanted.

Lessons learned on managing Windows Taskbar and Start Menu colouring in VirtualBox virtual machines

In the last few weeks, I have had a few occasions when the colouration of the Windows 10 taskbar and its Star Menu has departed from my expectations. At times, this happened in VirtualBox virtual machine installations and both the legacy 5.2.x versions and the current 6.x ones have thrown up issues.

The first one actually happened with a Windows 10 installation in VirtualBox 5.2.x when the taskbar changed colour to light grey and there was no way to get it to pick up the colour of the desktop image to become blue instead. The solution was to change the Windows from Light to Dark in order for the desired colouration to be applied and the settings above are taken from the screen that appears on going to Settings > Personalisation > Colours.

The second issue appeared in Windows 10 Professional installation in VirtualBox 6.0.x when the taskbar and Start Menu turned transparent after an updated. This virtual machine is used to see what is coming in the slow ring of Windows Insider so some rough edges could be expected. The solution here was to turn off 3D acceleration in the Display pane of the VM settings after shutting it down. Starting it again showed that all was back as expected.

Both resolutions took a share of time to find and there was a deal of experimentation needed too. Once identified, they addressed the issues as desired so I am recording here for use by others as much as future reference for myself.

Shared folders not automounting on an Ubuntu 18.04 guest in a VirtualBox virtual machine

Over the weekend, I finally got to fixing a problem that has affected Ubuntu 18.04 virtual machine for quite a while. The usual checks on Guest Additions installation and vboxsf group access assignment were performed but were not causing the issue. Also, no other VM (Windows (7 & 10) and Linux Mint Debian Edition) on the same Linux Mint 19.2 machine was experiencing the same issue. The latter observation made the problem intrinsic to the Ubuntu VM itself.

Because I install the Guest Additions software from the included virtual CD, I executed the following command to open the relevant file for editing:

sudo systemctl edit --full vboxadd-service

If I had installed installed virtualbox-guest-dkms and virtualbox-guest-utils from the Ubuntu repositories instead, then this would have been the command that I needed to execute instead of the above.

sudo systemctl edit --full virtualbox-guest-utils

Whichever configuration gets opened, the line that needs attention is the one beginning with Conflicts (line 6 in the file on my system). The required edit removes systemd-timesync.service from the list following the equals sign. It is worth checking that file paths include the correct version number for the Guest Additions software that is installed in case this was not the case. The only change that was needed on my Ubuntu VM was to the Conflicts line and rebooting it got the Shared Folder automatically mounted under the /media directory as expected.

Creating a VirtualBox virtual disk image using the Linux command line

Much of the past weekend was spent getting a working Debian 10 installation up and running in a VirtualBox virtual machine. Because I chose the Cinnamon desktop environment, the process was not as smooth as I would have liked so a minimal installation was performed before I started to embellish as I liked. Along the way, I got to wondering if I could create virtual hard drives using the command line and I found that something like the following did what was needed:

VBoxManage createmedium disk --filename <full path including file name without extension> -size <size in MiB> --format VDI --variant Standard

Most of the options are self-explanatory part from the one named variant. This defines whether the VDI file expands to the maximum size specified using the size parameter or is reserved with the size defined in that parameter. Two VDI files were created in this way and I used these to replace their Debian 8 predecessors and even to save a bit of space too. If you want, you can find out more in the user documentation but this post hopefully gets you started anyway.

Enlarging a VirtualBox VDI virtual disk

It is amazing how the Windows folder manages to grow on your C drive and on in a Windows 7 installation was the cause of my needing to expand the VirtualBox virtual machine VDI disk on which it was installed. After trying various ways to cut down the size, an enlargement could not be avoided. In all of this, it was handy that I had a recent backup for restoration after any damage.

The same thing meant that I could resort to enlarging the VDI file with more peace of mind than otherwise might have been the case. This needed use of the command line once the VM was shut down. The form of the command that I used was the following:

VBoxManage modifyhd <filepath/filename>.vdi --resize 102400

It appears that this also would work on a Windows host but mine was Linux and it did what I needed. The next step was to attach it to an Ubuntu VM and use GParted to expand the main partition to fill the newly available space. That does not mean that it takes up 100 GiB on my system just yet because these things can be left to grow over time and there is a way to shrink them too if you ever need to do just that. As ever, having a backup made before any such operation may have its uses if anything goes awry.

Lightening of desktop background images on Linux Mint Debian Edition running in Virtualbox

After a recent upgrade to Linux Mint Debian Edition 3 in a VirtualBox virtual machine that I had running its predecessor, I began to notice that background images were being loaded with more washed out of faded colours. This happened at startup so selecting another background image worked as intended until the same thing happened to that after a system restart.

This problem is not new and has affected the Cinnamon desktop in the main Linux Mint variant (the one that is based on Ubuntu) and issuing the following command in a terminal session is a suggested solution:

gsettings set org.cinnamon.muffin background-transition fade-in

In my case, that solved the problem and desktop background image display is as it should be since I executed the above. All it took was a change to a system setting.

Using PowerShell to reinstall Windows Apps

Recently, I managed to use 10AppsManager to remove most of the in-built apps from a Windows 10 virtual machine that I have for testing development versions in case anything ugly were to appear in a production update. Curiosity is my excuse for letting the tool do what it did and some could do with restoration. Out of the lot, Windows Store is the main one that I have sorted so far.

The first step of the process was to start up PowerShell in administrator mode. On my system, this is as simple as clicking on the relevant item in the menu popped up by right clicking on the Start Menu button and clicking on the Yes button in the dialogue box that appears afterwards. In your case, it might be a case of right clicking on the appropriate Start Menu programs entry, selecting the administrator option and going from there.

With this PowerShell session open, the first command to issue is the following:

Get-Appxpackage -Allusers > c:\temp\appxpackage.txt

This creates a listing of Windows app information and pops it into a text file in your choice of directory. Opening the text file in Notepad allows you to search it more easily and there is an entry for Windows Store:

Name                   : Microsoft.WindowsStore
Publisher              : CN=Microsoft Corporation, O=Microsoft Corporation, L=Redmond, S=Washington, C=US
Architecture           : X64
ResourceId             :
Version                : 11607.1001.32.0
PackageFullName        : Microsoft.WindowsStore_11607.1001.32.0_x64__8wekyb3d8bbwe
InstallLocation        : C:\Program Files\WindowsApps\Microsoft.WindowsStore_11607.1001.32.0_x64__8wekyb3d8bbwe
IsFramework            : False
PackageFamilyName      : Microsoft.WindowsStore_8wekyb3d8bbwe
PublisherId            : 8wekyb3d8bbwe
PackageUserInformation : {S-1-5-21-3224249330-198124288-2558179248-1001
IsResourcePackage      : False
IsBundle               : False
IsDevelopmentMode      : False
Dependencies           : {Microsoft.VCLibs.140.00_14.0.24123.0_x64__8wekyb3d8bbwe,
Microsoft.NET.Native.Framework.1.3_1.3.24201.0_x64__8wekyb3d8bbwe,
Microsoft.NET.Native.Runtime.1.3_1.3.23901.0_x64__8wekyb3d8bbwe,
Microsoft.WindowsStore_11607.1001.32.0_neutral_split.scale-100_8wekyb3d8bbwe}

Using the information from the InstallLocation field, the following command can be built and executed (here, it has gone over several lines so you need to get your version onto a single one):

Add-AppxPackage -register “C:\Program Files\WindowsApps\Microsoft.WindowsStore_11607.1001.32.0_x64__8wekyb3d8bbwe\AppxManifest.xml” -DisableDevelopmentMode

Once the above has completed, the app was installed and ready to use again. As the mood took me, I installed other apps from the Windows Store as I saw fit.

Forcing an upgrade to Windows 10 Anniversary Update

There remain people who advise those on Windows 7 or 8.x to hold fire on upgrading to Windows 10. Now that the free upgrade no longer is available, that advice may hold more weight than it did. Even so, there are those among us who jumped ship who do not mind having the latest versions of things at no monetary cost to see what is available and I must admit to being one of those.

After all, I do have a virtual machine with a pre-release version of the next update to Windows 10 installed on there to see what might be coming our way and to get a sense of what changes that may bring so that I am ready for those. Otherwise, I usually am happy to wait but I noticed that the Windows 10 Anniversary Update only came to my HP Pavilion dm4 laptop and not other machines with Windows 10 installed so I started to wonder why there was a lag when it came to automatic upgrades.

So that these things do not arrive when it is least convenient, I took advantage of a manual method in order to choose my timing. This did not involve installation from a disk image but was in-situ. The first part of the process is standard enough in that the Settings app was started and the Update & security item chosen. That dropped me onto the Windows Update and I first clicked on the Check for updates button to see what would happen. When nothing came of that, the Learn more link was clicked to bring me onto part of the Microsoft support website where I found that the Windows 10 Anniversary Update installer could be downloaded so I duly did just that.

Running it produced a screen asking whether or not I wanted to proceed. Since I wanted to go ahead, the appropriate button was clicked and the machine left alone until the process complete. Because the installer purely is a facilitator, the first stage is to download the rest of the files needed and that will take a while on any connection. Once downloading was completed, the actual process of installation commenced with several restarts before a log-in screen was again on offer. On logging in to the machine, the last part of the process started.

The process took quite a while but seemingly worked without a hitch. If there was anything that I needed to do, it was the re-installation of VirtualBox Guest Additions to restore access to shared folders as well as dealing with a self-inflicted irritation. Otherwise, I have found that previously installed software worked as expected and no file has been missed. Waiting a while may have had its advantages too because initial issues with the Anniversary Update will have been addressed but it is best not to leave it too long or you could have the feeling of being forgotten. A happy balance needs striking.

Compressing a VirtualBox VDI file for a Linux guest

In a previous posting, I talked about compressing a virtual hard disk for a Windows guest system running in VirtualBox on a Linux system. Since then, I have needed to do the same for a Linux guest following some housekeeping. The Linux distribution used is Debian so the instructions are relevant to that and maybe its derivatives such as Ubuntu, Linux Mint and their kind.

While there are other alternatives like dd, I am going to stick with a utility named zerofree to overwrite the newly freed up disk space with zeroes to aid compression later on in the process for this and the first step is to install it using the following command:

apt-get install zerofree

Once that has been completed, the next step is to unmount the relevant disk partition. Luckily for me, what I needed to compress was an area that I reserved for synchronisation with Dropbox. If it was the root area where the operating system files are kept, a live distro would be needed instead. In any event, the required command takes the following form with the mount point being whatever it is on your system (/home, for instance):

sudo umount [mount point]

With the disk partition unmounted, zerofree can be run by issuing a command that looks like this:

zerofree -v /dev/sdxN

Above, the -v switch tells zerofree to display its progress and a continually updating percentage count tells you how it is going. The /dev/sdxN piece is generic with the x corresponding to the letter assigned to the disk on which the partition resides (a, b, c or whatever) and the N is the partition number (1, 2, 3 or whatever; before GPT, the maximum was 4). Putting all this together, we get an example like /dev/sdb2.

Once, that had completed, the next step is to shut down the VM and execute a command like the following on the host Linux system ([file location/file name] needs to be replaced with whatever applies on your system):

VBoxManage modifyhd [file location/file name].vdi --compact

With the zero filling in place, there was a lot of space released when I tried this. While it would be nice for dynamic virtual disks to reduce in size automatically, I accept that there may be data integrity risks with those so the manual process will suffice for now. It has not been needed that often anyway.